All offices must be well ventilated. To meet increasingly stringent Health and Safety regulations, a continuous supply of fresh air is necessary.
Adequate ventilation is also a pre-requisite for a healthy and productive workforce. Studies show that workers who are comfortable in their working environment are over 60% more productive. Workers in a well-ventilated office are also less likely to become ill.
There are several methods to ventilate an office space. The best choice for you will depend on the office size and the range of equipment in use. An office with lots of staff, computers, and machinery will generate more heat, thus requiring better ventilation. When ventilating your office, it’s important to consider these options.
A natural ventilation system circulates air in a building without using a mechanical system. External air is directed through the internal space by using advanced control systems.
The control system can be connected to a variety of different sensor types including rain, wind, and temperature sensors. The control system can also be linked to a manual controller such as a switch or remote control to activate the ventilation process.
When designing your natural ventilation system, you must consider several factors. These include:
Building location – Whether it’s urban or more isolated. Sheltered or exposed.
Building height – The higher the building, the more external conditions will influence its natural ventilation.
Indoor layout and partitions – The interior set up will both restrict and enable air flow.
Window types – The size, shape, and opening arc of any windows will directly affect the ventilation capacity.
The type of natural ventilation system suitable for a building will ultimately be determined by a combination of the building’s natural external environment and the interior layout and building structure.
In the event of fire, all office buildings must be designed to facilitate the safe escape of workers. A smoke ventilation system will release smoke from stairwells, atriums, and corridors to allow a safer exit.
Smoke ventilation systems can be manually or automatically activated. Smoke sensors or smoke alarms can directly link to the smoke vent, automatically triggering its opening when smoke is detected.
Smoke vents can also be manually activated by an emergency break glass point or by a Fire Officer at an override switch. Once the smoke ventilation system is activated, the vent will remain open until all smoke has dissipated or the system has been manually reset.
Alongside Window Actuators connected to natural and smoke ventilation systems, there are a range of independent automatic window opening systems available. Remote window opening actuators are perfect for large office spaces, particularly where windows are situated out of reach at a high level.
Window actuators can be controlled by a selection of switches, key switches, remote transmitters and receivers, and 24V DC transformers. Window automation can be designed and implemented into the ventilation system or work separately to allow increased airflow when necessary.
At Teal Products, we have over 17 years’ experience supplying high quality window control products and ventilation systems.
We pride ourselves on our outstanding customer service and are always happy to offer advice on product specification and installation. When you want to create a comfortable and well-ventilated office space, Teal Products can provide you with the best solution.
Today, glass used in the building industry must combine a number of different functions. POLFLAM® fire-resistant glass meets those requirements. It is a perfectly flexible and multifunction product which lives up to the current market trends.
Fire-resistant glass – why did it happen? For optical lightness of a building and to fill it with natural daylight. It was in no time that fire-resistant glass replaced ordinary opaque indoor walls or the old-type construction glass for facades.
Today, we also have it in ceilings and stairs which is not the end of the story. POLFLAM® fire-resistant glass may have a number of different functions beside its basic one.
Firstly: resistance to fire
POLFLAM® glass has been made in all the fire-resistance classes, from EI 30, through EI 60, EI 90 and EI 120, up to EI 180. Following the PN-EN 1363-1 standard, it meets the fire tightness criteria, which has been confirmed with many tests carried out in notified European laboratories.
In the production process, POLFLAM® uses a state-of-the-art hydrogel technology. The latter accounts for ideal functional parameters of the glass units, like high transparency or acoustic insulation. What’s more, the glass acquires extra functionalities thanks to the technology allowing sealing additional panes to the unit.
Secondly: enhanced resistance
POLFLAM® fire-resistant glass with an extra glass pane of higher safety class (P), is a model example of the multifunction product. It can be a curtainwall being, at the same time, resistant to impact, which means that the glass also protects against burglary.
POLFLAM laminated glass is available in all the resistance classes, from P2 to P7. It has been applied in floors or display windows, and in doors, windows or facades.
Thirdly: acoustic insulation
Curbing noise levels in buildings designed for use by people has currently been such an important issue to have it regulated by construction law. Therefore, architects will ask for materials, including glass, of high sound control and sound absorption parameters.
These are of particular importance when we take conference rooms or glass walls separating open-space areas, needless to mention concert halls, where sound control is absolute priority.
POLFLAM® fire-resistant glass lives up to the sound proofing parameters recommended in spaces of particular noise load. Its bear unit’s Rw factor is 40-47 dB, depending of the EI class, while the unit with appropriate extra glass panes sealed to it easily achieves Rw of up to 52 dB!
Fourthly: PD-LCD, that is, changeable transparency
When adding to the unit a so called intelligent glass pane based on the liquid crystals technology, POLFLAM® fire-resistant glass partitions acquire a completely new function.
Glass units passing from transparency to full opacity make it possible, if need be, to isolate office spaces without using any blinds or to make ad hoc overhead screens in museums or art galleries, or partitions in hospital spaces. This type of glass when applied in facades allows architects to abandon traditional sunshades.
Fifthly: self-cleaning function
The self-cleaning layer is an ideal solution for fire-resistant glass applied in hard to reach or difficult to clean places, like facades or skylights. Under the influence of UV radiation, the dirt on the glass decomposes in the process of photocatalysis and flows down completely with the rain. With this layer, POLFLAM® glass keeps the facade shiny and transparent with no sign of dirt or stains.
Sixthly: thermal insulation
Heat losses are another important issue for facades, including those resistant to fire. POLFLAM® glass can be sealed with most float glasses available on the market that have perfect thermal properties.
For double cavity units sealed to POLFLAM® glass, the Ug factor is as low as 0.5 [W/m2 K]. The lower the Ug, the lower the heat losses through glass and the better the savings all through the heating period.
Seventh: solar control
This issue is of utmost importance for facades exposed to the south or west, especially in the summer. Through using a selective-layer glass pane added to POLFLAM® fire-resistant glass solar radiation can be reflected and, thus, solar penetration controlled.
The latter protects buildings against overheating, which not only means better working conditions but also tangible financial benefits – bearing in mind the cost of cooling and air conditioning that is higher than the cost of heating.
Today, glass used in the building industry must combine a number of different functions. POLFLAM® fire-resistant glass meets those requirements. It is a perfectly flexible and multifunction product which lives up to the current market trends.
Post-Grenfell, Tim Kempster, managing director of Wrightstyle, looks at fire safety in tall buildings.
The Grenfell Tower disaster will cast a long shadow for many years to come, helping to define official attitudes to social housing and the imperative of fire safety in tall buildings.
While it’s too early to point fingers, it seems apparent that UK authorities have been complacent in believing that current regulations were fit for purpose and that, once again, it will be a case of “codifying by catastrophe.”
But it’s worth remembering that, while official enquiries grind forward, the building industry is still building upwards – and that fire safety in tall buildings is in a spotlight like never before.
Most of the UK’s tall buildings are in London, with others in Manchester, Birmingham, Leeds, Liverpool, Sheffield, Swansea and Brighton.
In London, there are 450 tall buildings in the pipeline. Of those, over 90 are being constructed, and the pace of upward development in the capital is accelerating, with 28 tall building completions this year, and 40 more in 2018. Brexit, it would appear, has yet had little dampening effect.
Those figures come from the London Tall Buildings Survey, which charts the number of towers of 20 storeys or more completed, proposed or currently in planning across the capital’s 33 boroughs.
The tallest residential building both in London and Europe will be the 67-storey Spire London at 235 metres high, near Canary Wharf, and scheduled for completion in 2020.
Or Chelsea Waterfront which will have two glass residential towers of 37 and 25 storeys, and Keybridge, the UK’s tallest residential brick tower, at 37 storeys, and 1 Undershaft, which will be the second-tallest building in western Europe – and the tallest building in the City of London.
The Shard remains the tallest building in both the UK and Europe, topping out at 310 metres with 87 storeys. It has 11,000 panes of glass and a total surface area of 56,000 square metres, and is partly residential.
Its early designs were influenced by a report from the US National Institute of Standards and Technology (NIST) into the collapse of the Twin Towers in September 2001, which were just over 400 metres tall, which found that “the towers withstood the impacts and would have remained standing were it not for the dislodged insulation (fireproofing) and the subsequent multi-floor fires.”
While the Shard is the tallest building in Europe, it will be dwarfed by the tallest of them all, the Kingdom Tower in Jeddah, Saudi Arabia – the first habitable building to pass the one kilometre mark, and due for completion in 2019.
The £780 million Kingdom Tower will stand at just over 1,000 metres, have 200 storeys, and require some 500,000 cubic metres of concrete and 80,000 tons of steel. It will also be partly residential.
It will be three times higher than the Shard and 173 metres taller than Dubai’s Burj Khalifa, currently the world’s tallest building at over 828 metres – with 160 storeys.
The challenges will be immense, not least how to pump wet cement half a mile upwards. To erect the Burj Khalifa, cement pumping took place at night to reduce heat.
World Trade Center
But it’s China that is setting the pace, with a number of ultra high-rise developments, including the Shanghai Tower which, at 632 metres, is China’s tallest building – and the second tallest in the world.
The new 541 metre One World Trade Center, the building that replaced the Twin Towers, is the only US skyscraper in the Top 10 tallest buildings in the world at 541 metres – but not for long as other countries build further into the sky.
Third in the super-tall list is the Makkah Royal Clock Tower Hotel, in Mecca, Saudi Arabia. Besides hotel rooms, the tower has a conference centre, an Islamic Museum and prayer room for up to 10,000 people, a Lunar Observation Centre for watching the moon during the Holy Month, and a shopping mall with five storeys.
In London, with high land prices, the logic of building upwards is inescapable, and creating high-rise residential blocks will help to alleviate the city’s chronic housing shortage – if design lessons from the past can be learned.
Glasgow’s Red Road flats are a case in point. Built in the early 1960s, and Europe’s highest residential blocks when they were built, the steel-framed buildings were fire-proofed with asbestos, which blighted the flats for years.
But the biggest lesson for architects, building designers and fire safety experts must be to take heed of Grenfell Tower and to never again lapse into false security. That’s the real lesson from that disaster – that complacency is the enemy of fire safety.
At Wrightstyle, we have worked on fire safety on a number of high-rise developments in the UK and internationally. We have also publicly raised concerns about fire regulations in both the UK and UAE, and changed our certification processes, so that a fire certification on one of our glazing systems could not be unilaterally applied on another project.
In the new generation of super-buildings, fire safety takes on a whole new dimension, because – beyond sprinkler systems – how do you tackle a fire a kilometre up in the sky?
The answer is: with great difficulty, and there have been several notable cases where a sprinkler system has made things worse, with cold water coming into contact with non-fire rated glass and causing the glass to break and allowing more oxygen to reach the seat of the fire. The same is true of tempered glass, with a limited fire-rating.
The most effective way of dealing with fire at high altitude is by fire compartmentation: keeping the fire contained in one protected area and preventing it from spreading. A contained fire can be dealt with; an uncontrolled fire can’t.
A rule of thumb for fire safety in supertall buildings is that any fire should be able to burn itself out, without external intervention, and without building collapse. That allows for a limited evacuation of people on the affected floor and on floors immediately above and below the fire.
In that context, in the 1950s, Frank Lloyd Wright once proposed The Illinois, a mile-high skyscraper of nearly 550 storeys, with enough room for 100,000 people. It was fanciful then, but not so fanciful now. It’s probably only a matter of time before human imagination and construction technology make it possible.
Over the years, we’ve seen the good, bad and the ugly of fire safety design, and hope that the new cities in the sky pay heed to the absolute need for a whole new level of fire safety and, if the worst does happen, have fire containment strategies to ensure everyone’s safety.
After Grenfell, that’s the least that we in the UK can do.
A comprehensive fire protection program addresses at least three things: detection, suppression and compartmentation. Detection devices such as smoke and fire alarms provide early warnings and are essential for alerting people to danger.
Strategically placed sprinklers and extinguishers can make a tremendous difference in how quickly a fire can be suppressed.
The important job of compartmentation is often overlooked, because it is the work of more passive forms of protection. The very materials a building is constructed with do the job of containing a fire in a limited area, keeping it from spreading unchecked throughout a building. Walls, ceiling tiles and sealants all serve as firestops.
One practically invisible firefighter can be glass. Great advances have been made in fire-rated glazing materials, making glass a powerful ally in efforts to provide life safety.
Ordinary window glass cannot withstand the high temperatures associated with a structure fire, and it will break and fall out of its frame at about 250° F, only a few minutes into a fire. On the other hand, glass that is classified as “fire-rated” for at least 60 minutes can tolerate heat in excess of 1600° F.
For decades, fire-rated glazing was limited to one product: polished wired glass. It was the only glass able to survive the rigorous testing process. Yet wired glass has its drawbacks. Many people mistakenly assume that the wires make the glass stronger and more impact resistant. In reality, wired glass is only 1/4 as strong as tempered or laminated glass and provides a minimal amount of protection against impact.
With such low impact resistance, current building codes have eliminated the use of traditional wired glass in what are considered “hazardous” locations (doors, sidelites, windows near the floor, etc.).
When wired glass was the only fire-rated glass option available, it posed a real dilemma: Which priority takes precedence — fire safety or impact safety? One or the other had to be compromised in many locations, simply because no product existed that could fully satisfy both needs.
Fortunately, the situation has changed dramatically. A number of newer, “wire-free” products have emerged that are greatly expanding choices. Diverse in make-up and characteristics, these new materials have been able to substantially surpass wired glass in terms of fire and impact safety performance.
One category of fire-rated glass that has emerged isn’t technically a glass at all. In fact, it is ceramic. Ceramic has long been known for its outstanding heat tolerance, which is why you’ll find it used in everything from kitchen cooktops to car engines. Utilizing state-of-the-art technology, manufacturers have developed the ability to create transparent sheets of ceramic that look like ordinary window glass. Glass ceramic (such as the FireLite® family of products) has earned fire ratings up to 3 hours.
Ceramic also is available with high impact safety ratings, making it an ideal option for high traffic areas such as busy corridors and lobbies in schools and hospitals. It can be specified in insulated units to meet energy codes for exterior applications.
Another category of wireless fire-rated glass found in the market today is specially tempered glass. This group offers limited fire protection, because specially tempered glass cannot withstand what is known as “thermal shock.” When glass is tested for a fire rating for more than 20 minutes, it is blasted with water from a fire hose immediately after being heated in a furnace fire.
This important test makes sure the glazing product, hot from the fire, will stay in place if sprayed with water from sprinklers or other sources. Specially tempered glass cannot survive this portion of the test, and so the codes dictate that it can only be given a 20-minute rating. The limitations of this product category are important to keep in mind, because specially tempered glass is sometimes marketed inappropriately as carrying higher ratings “without the hose stream test,” when in reality, passing that test is not optional for a 45 or 60 minute rating.
Simply stated, do not accept the use of products listed for 45 or 60 minutes that have not passed the required fire hose stream portion of national test standards. If you do, you may be accepting unneeded risks and liability.
Glass firewalls are another classification of fire-rated glass. These products are actually tested to the same standards as solid walls, with ratings up to 2 hours. In addition to stopping flames and smoke, glass firewalls block the transfer of heat, similar to a fire-rated masonry wall. As little heat passes through the glass during a fire, glass fire walls can be installed from wall to wall and floor to ceiling, and include glass doors, if desired. Designers then can divide space without the use of solid walls that diminish visibility, security and light.
Of course, all these glass options need to be installed in frames. Until recently, framing options lagged behind fire-rated glazing in terms of new developments. In most cases, designers were forced to resort to traditional hollow metal steel frames. However, new narrow profile European style doors and framing have changed that. Products such as Fireframes® now offer new opportunities for architects seeking alternatives to traditional wrap-around framing.
Some code officials will occasionally allow trade-offs, where architects can substitute sprinklers and ordinary window glass for fire-rated glazing. However, testing has shown that in some cases, sprinklers can actually cause non fire-rated glass to shatter and fall out of the frame. Unless the glass is completely bathed in water early in the fire, the glass experiences the thermal shock mentioned earlier. When it vacates the opening, flames and smoke are no longer restricted from entering a space.
What’s more, since sprinklers are “active” systems, they require a number of steps to occur as planned in order to function properly. Human error, power outages, interrupted water supplies, melting pipes and even paint have interfered with sprinkler performance.
Sprinklers have saved countless lives and are a critical component in fire safety. However, reliance on a single system for fire protection may create unnecessary risk, particularly when the system can be affected by so many variables. The ideal fire protection plan should include passive systems such as fire-rated glass in addition to more active systems such as “deluge” sprinklers where glass is in the area.
The new developments in fire-rated glazing and framing continue to raise the standard for both performance and design. When properly specified and installed, fire-rated glazing and framing systems can be powerful friends in the fight against the devastating effects of fire.
by Jerry Razwick
Jerry Razwick is founder and president of Technical Glass Products (TGP), a distributor of specialty glass and framing as well as architectural products. He has been a glass factory agent in foreign and domestic markets for over 25 years. Mr. Razwick has served on the Industry Advisory Committee for Underwriters Laboratories, Inc. and is an active member of AIA, CSI, NGA and GANA.
Glass is one of the most popular and versatile building materials used today, due in part to its constantly improving solar and thermal performance. One way this performance is achieved is through the use of passive and solar control low-e coatings. So, what is low-e glass? In this section, we provide you with an in-depth overview of coatings.
In order to understand coatings, it’s important to understand the solar energy spectrum or energy from the sun. Ultraviolet (UV) light, visible light and infrared (IR) light all occupy different parts of the solar spectrum – the differences between the three are determined by their wavelengths.
Ultraviolet light, which is what causes interior materials such as fabrics and wall coverings to fade, has wavelengths of 310-380 nanometers when reporting glass performance.
Visible light occupies the part of the spectrum between wavelengths from about 380-780 nanometers.
Infrared light (or heat energy) is transmitted as heat into a building, and begins at wavelengths of 780 nanometers. Solar infrared is commonly referred to as short-wave infrared energy, while heat radiating off of warm objects has higher wavelengths than the sun and referred to as long-wave infrared.
Low-E coatings have been developed to minimize the amount of ultraviolet and infrared light that can pass through glass without compromising the amount of visible light that is transmitted.
When heat or light energy is absorbed by glass, it is either shifted away by moving air or re-radiated by the glass surface. The ability of a material to radiate energy is known as emissivity. In general, highly reflective materials have a low emissivity and dull darker colored materials have a high emissivity. All materials, including windows, radiate heat in the form of long-wave, infrared energy depending on the emissivity and temperature of their surfaces. Radiant energy is one of the important ways heat transfer occurs with windows. Reducing the emissivity of one or more of the window glass surfaces improves a window’s insulating properties. For example, uncoated glass has an emissivity of .84, while Vitro Architectural Glass’ (formerly PPG glass) solar control Solarban® 70XL glass has an emissivity of .02.
This is where low emissivity (or low-e glass) coatings come into play. Low-E glass has a microscopically thin, transparent coating—it is much thinner than a human hair—that reflects long-wave infrared energy (or heat). Some low-e’s also reflect significant amounts of short-wave solar infrared energy. When the interior heat energy tries to escape to the colder outside during the winter, the low-e coating reflects the heat back to the inside, reducing the radiant heat loss through the glass. The reverse happens during the summer. To use a simple analogy, low-e glass works the same way as a thermos. A thermos has a silver lining, which reflects the temperature of the drink it contains. The temperature is maintained because of the constant reflection that occurs, as well as the insulating benefits that the air space provides between the inner and outer shells of the thermos, similar to an insulating glass unit. Since low-e glass is comprised of extremely thin layers of silver or other low emissivity materials, the same theory applies. The silver low-e coating reflects the interior temperatures back inside, keeping the room warm or cold.
Low-e Coating Types & Manufacturing Processes
There are actually two different types of low-e coatings: passive low-e coatings and solar control low-e coatings. Passive low-e coatings are designed to maximize solar heat gain into a home or building to create the effect of “passive” heating and reducing reliance on artificial heating. Solar control low-e coatings are designed to limit the amount of solar heat that passes into a home or building for the purpose of keeping buildings cooler and reducing energy consumption related to air conditioning.
Both types of low-e glass, passive and solar control, are produced by two primary production methods – pyrolytic, or “hard coat”, and Magnetron Sputter Vacuum Deposition (MSVD), or “soft coat”. In the pyrolytic process, which became common in the early 1970’s, the coating is applied to the glass ribbon while it is being produced on the float line. The coating then “fuses” to the hot glass surface, creating a strong bond that is very durable for glass processing during fabrication. Finally, the glass is cut into stock sheets of various sizes for shipment to fabricators. In the MSVD process, introduced in the 1980’s and continually refined in recent decades, the coating is applied off-line to pre-cut glass in a vacuum chambers at room temperature.
Because of the historic evolution of these coating technologies, passive low-e coatings are sometimes associated with the pyrolytic process and solar control low-e coatings with MSVD, however, this is no longer entirely accurate. In addition, performance varies widely from product to product and manufacturer to manufacturer (see table below), but performance data tables are readily available and several online tools can be used to compare all low-e coatings on the market.
In a standard double panel IG there are four potential surfaces to which coatings can be applied: the first (#1) surface faces outdoors, the second (#2) and third (#3) surfaces face each other inside the insulating glass unit and are separated by a peripheral spacer which creates an insulating air space, while the fourth (#4) surface faces directly indoors. Passive low-e coatings function best when on the third or fourth surface (furthest away from the sun), while solar control low-e coatings function best when on the lite closest to the sun, typically the second surface.
Low-e Coating Performance Measures
Low-e coatings are applied to the various surfaces of insulating glass units. Whether a low-e coating is considered passive or solar control, they offer improvements in performance values. The following are used to measure the effectiveness of glass with low-e coatings:
U-Value is the rating given to a window based on how much heat loss it allows.
Visible Light Transmittance is a measure of how much light passes through a window.
Solar Heat Gain Coefficient is the fraction of incident solar radiation admitted through a window, both directly transmitted and absorbed & re-radiated inward. The lower a window’s solar heat gain coefficient, the less solar heat it transmits.
Light to Solar Gain is the ratio between the window’s Solar Heat Gain Coefficient (SHGC) and its visible light transmittance (VLT) rating.
Here’s how the coatings measure up by minimizing the amount of ultra-violet and infrared light (energy) that can pass through glass without compromising the amount of visible light that is transmitted.
When thinking of window designs: size, tint and other aesthetic qualities come to mind. However, low-e coatings play an equally important role and significantly affect the overall performance of a window and the total heating, lighting, and cooling costs of a building.
HOMEOWNERS, BUILDERS AND architects choose to use low-E Glass in their windows for one reason: energy efficiency. Of Course, low-E glass brings other benefits such as increased Comfort and condensation resistance, but the primary function is Improved energy efficiency – whether the driving force is to meet Building codes or to reduce utility costs. However, those who use Low-E glass must be careful in their selection, as not all low-E Glass is the same.
The impact of sunlight
All low-E glass improves the insulating value of the window in Basically the same way. A thin coating based on either silver or tin Oxide is deposited on the glass. This coating transmits visible Light, but reflects longer wavelength infrared light associated with Radioactive heat emitted by all warm objects. By reflecting this Radioactive heat back into the room, the coating reduces heat loss From the building, resulting in a lower overall heat transfer Coefficient (U or K).
Because of its relative simplicity, there has been a tendency to Compare only the U value for different windows and glazing Options, just as one would do for wall insulation. However, it is Inaccurate to treat a window as if it were an opaque wall, ignoring The effect of sunlight coming through the window. Sunlight is a Significant source of free energy into the building, which can be Either beneficial or detrimental, depending on the building Location. Thus, to accurately evaluate window performance, the Solar heat gain coefficient (SHGC or g) must also be considered, As its impact on energy consumption can be the same or even Larger than that due to the U value. For this reason, modern Window rating programmers such as the European Window Energy Rating System (EWERS) and performance-based building codes Are moving away from considering only U value to formulas Including both U and SHGC.
Those who use low-E glass must be aware of both properties, Because although all low-E glass will have a reduced U value, Different products can vary widely in actual performance by having either high or low solar heat gain. In warm climates, where Energy consumption is dominated by air conditioning, windows With low solar heat gain are preferable to reduce cooling Demand. In colder climates where heating is the major concern, High solar gain windows are preferable, as they let in the free Energy of the sun to reduce heating fuel consumption. Special Care must be taken in cold climates, because as the U value is Reduced, the solar heat gain is reduced even further for many Coatings. Therefore, although a low-E glass with a very low U Value appears to be the best choice, it may actually have worse Performance if it has low solar heat gain that blocks the warmth Of the sun and increases heating requirements. For example, the energy rating of an insulating glass unit (IGU)
With U=1.1 W/m2K and SHGC=0.30 is actually worse than an IGU
With U=1.6 W/m2K and SHGC=0.55 for typical homes in the UK and
Denmark, despite the lower U value. The improved insulating level
Is offset by low solar heat gain, which reduces the benefits of Passive solar heating. In conclusion, it is not enough to only look at U value when Selecting low-E glass. The solar heat gain, which can vary widely Between products, must also be considered, based on the local Climate. Window rating systems that include both U and SHGC in A simple energy rating, such as EWERS, is useful tools in making This decision.
Authors & Company Profile
Dr Thomas D Culp is manager of energy policy and New technologies, and Rein de Varies is European Marketing manager, both at Atofina Chemicals Inc, A branch of the oil group Total. Atofina Chemicals Supplies the glass industry with technology for manufacturing low-E coatings. Atofina enjoys leading Positions both in Europe and the world in each of its Three core activities: base chemicals and commodity Polymers, intermediates and performance polymers, and specialty chemicals.
Low E glass, E stands for emissivity, was introduced in 1979 and is now a great favorite among contractors. Low E glass works by reflecting heat the same during the winter and summer, using a thin metallic coating on or in the glass. These windows can be installed almost in all regions of the world, but the main factor is related to the building design and window position. As a builder, you can use them for your new projects or even in major renovations, ideally for healthcare facilities as maintaining temperatures is critical in some of these facilities.
These windows can provide many benefits for the building owner as they can save as much as 50 percent in energy use, provide greater operational efficiency, improved access to daylight and natural views for occupants without increasing energy costs for heating and cooling.
Why choose low-e windows Instead of regular windows?
Low-E windows can provide aesthetic value to building occupants, and they will not reduce the amount of light entering the building while maintaining the natural look of windows. However, windows can also represent a large source of heat gain or loss, because when the right window is not used, it can increase heating costs and A/C usage, making it more costly to operate your building.
Similarly, windows with a poor ability to keep heat in allow warm air to escape the building in the winter, increasing the demands on heating systems. Window manufacturers have developed many new insulating and glazing techniques to improve the performance of windows.
The National Fenestration Rating Council defines five performance areas to consider when choosing windows most suited for your local climate:
Look for Lower U-Factor Values – These numbers will represent how well a product prevents heat from escaping a home or building. Always look for U-values between 0.20 and 1.20, where lower numbers indicate a product better at keeping heat in.
Lower Solar Heat Gain Coefficient is Better – (SHGC) measures how well a product blocks heat from the sun from entering the building. SHGC is expressed as a number between 0 and 1, with a lower SHGC indicating a product that is better at blocking unwanted heat gain.
Visible Transmittance (VT) measures how much light comes through a product. VT is expressed as a number between 0 and 1 with a higher VT indicating a higher potential for day lighting.
Air Leakage (AL) measures how much outside air comes into a home or building through a product. AL rates typically fall in a range between 0.1 and 0.3 with a lower AL indicating a product that is better at keeping air out.
Condensation Resistance (CR) measures how well a product resists the formation of condensation. CR is expressed as a number between 1 and 100 with a higher CR indicating a product better able to resist condensation.
Not all low-e windows are suitable for all climates, so be sure to choose the right window for the climate where you are building. It is important to note that facilities in warmer climates should install windows with a lower SHGC and those in a cooler climate should install windows with a lower U-factor. Low-e coatings applied to exterior window panes prevent heat gains from exterior radiation; whereas low-e coatings applied to interior windows prevent heat loss.
Manufacturers often offer several low-e coatings with varying degrees of solar gain.
Low-E Windows Benefits and Costs
Windows manufactured with low-e coatings typically cost about 10 to 15 percent more than regular windows, but they reduce energy loss by as much as 30 to 50 percent.
Furthermore, this improvement in the building envelope—particularly when coupled with other strategies that improve the efficiency of the building envelope—ultimately impacts the demands of building HVAC systems. These benefits should be included in evaluating the lifecycle costs of installing efficient windows.
Efficient windows are defined by the climate of the building in which they will be installed. Engineers and vendors are able to make recommendations based on local climate and building orientation. Efficiency improvements to the building envelope directly impact the heating and cooling needs of the building; therefore, HVAC systems should be adjusted accordingly to account for decreased demands on the systems.
For a long time, the thermal performance of façades in research buildings has been undervalued because of the large volumes of air being moved through the space. Using the arsenal of strategies currently available to lab designers—such as chilled beams and low-flow fume hoods—air volumes in many contemporary research labs have been reduced to the minimums needed to maintain health and safety, and the performance of the building envelope is having an increasing influence on the building’s energy usage and thermal comfort.
Thermal bridging in building construction is a well-understood phenomenon frequently resulting from structural elements that penetrate through insulation layers and create a path for unimpeded heat transfer. While the construction industry has begun to develop materials and assemblies intended to mitigate this effect, there is little available research documenting the extent of the problem or the performance benefit that will result from the use of these new products. Anecdotal reports suggest that thermal bridges in conventional construction may reduce insulation effectiveness by as much as 40%.1
Payette received funding from the American Institute of Architect’s Upjohn Research Grant to better understand and quantify the impact of thermal bridging on the overall performance of the building envelope. The intent of this research is to bring rigor to the investigation of thermal bridges in commercial construction by using thermal imaging equipment to quantify actual performance of built installations; and use these results along with heat-transfer modeling software to suggest and then analyze performance improvements. Preliminary results suggest that through the use of readily available construction materials and careful detailing, it’s possible to effect a 50% or greater reduction in the impact of common thermal bridges (Figure 1).
In order to understand how façades are performing in the field, we used a thermal imaging camera to determine the R-value and identify sources of thermal bridges in recently completed projects designed by the firm. Teams were deployed to locate and document a range of façades and conditions. Using the methodology tested by Madding,2 we were able to measure the exterior air temperature, interior air temperature and radiant temperature in order to calculate the R-value of the assembly.
We collected thousands of images from visits to 15 buildings. These images were then organized by assembly type, and we noted conditions that were likely to affect performance, such as the transition to a foundation wall or adjacency of a window. Having established a library of data that was primarily focused on thermal bridging, the research team was able to identify typical problem areas thematically. We noted that they fell generally into two categories: one that is related to structure that supports façade and roof systems, and one that is more about material transitions.
Existing building façade renovations.
Masonry wall systems.
Metal panel wall systems.
Rainscreen wall systems.
Transitions and penetrations:
Transitions between new and existing façades.
Transitions between different wall systems.
Transitions between windows and walls.
Seismic and movement joints.
Using heat flow simulation software, such as Lawrence Berkley National Laboratory’s THERM, it’s possible to study alternative designs. The research team prepared THERM models of the areas being studied which were calibrated to the performance measured in the field with the thermal imaging camera. With validated THERM models in place, the research team is currently testing the quantitative impacts of potential design improvements.
The THERM modeling platform enables us to probe a detail and effectively measure the changes in heat transfer associated with different detailing or materials selections. Using this approach, we’re able to make quantifiable recommendations for improvements that can then be rigorously evaluated on a lifecycle basis for a specific project.
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Figure 2: Thermal images and details of the three cases studied.
Case study: Interior spray foam in existing buildings
Preliminary findings in our research show the actual R-value of many façades is approximately 40 to 70% less than the design-intended R-value, so our findings suggest far greater significance than was originally anticipated. As the amount of insulation we specify continues to increase, the conductive losses resulting from thermal bridging will continue to grow as a percentage of the building’s total energy load. Adding more insulation will have a diminishing return as the heat flow through the envelope is increasingly determined by the thermal bridges. Our research suggests that we are near a point now where the key to improving thermal performance lies in better detailing rather than increasing insulation thickness. A simple illustration of this is featured in the renovation case studies of three existing masonry façades.
Spray-applied insulation is once again gaining popularity particularly because of its ability to fill unseen voids and often provide an integral vapor barrier. In the northeast, it’s a particularly popular technology for renovating existing un-insulated masonry façades. Conventional details often call for metal studs to support interior gypsum board, and spray foam is installed between the studs following manufacturers’ recommendations. Unfortunately, this typical installation creates discontinuities at 16-in or 24-in center spacing. While the web of the steel stud is quite slender, they are highly effective heat-transfer devices because of the conductivity of the material and the flanges which provide significant contact area to collect and disperse heat.
Thermal images of three existing building’s renovations revealed dramatically different results. The first case, Building 1, had applied 3-in of insulation, Building 2 employed 2-in of insulation and Building 3 had used 4-in (Figure 2). While hand calculations of the thermal resistance would show the façade with the least insulation to be the poorest performer and the one with the most insulation to be the best, the thermal images revealed a different story. Building 1 had placed the steel studs flush against the exterior construction, resulting in an R-value that was 54% less than the calculated R-value. Building 2 pulled back the studs 1-in, allowing for half of the applied insulation to be continuous and decreasing the R-value by only 16%. As a result, Building 2 was observed to have a higher R-value than Building 1, despite having less insulation. Building 3 took the studs even further back, completely separating them from the insulation and resulting in a simulated R-value that was essentially identical to the design intention (Figure 3).
Our study showed that the continuity of the first inch is critical for the efficiency of the spray foam insulation performance. By simply pulling the studs in-board, even by a small amount, to allow a percentage of the insulation to be uninterrupted, the assembly R-value can be increased by about 70%. In the event that the studs are required to support exterior sheathing, it should be possible to fasten the sheathing using discontinuous shims or spacers so that once again, the majority of the insulation in that outer 1-in layer remains continuous. It’s important to remember that other factors—such as the continuity of the slab through the insulation, or window openings—will often decrease the thermal performance from our ideal conditions. But these too can be improved through careful detailing. The ultimate lesson is that small changes in the design that permit as little as an inch of continuous insulation can lead to dramatic improvement in overall performance.
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Figure 3: Simulations of the three spray foam cases studied.
Case study: Rainscreen supports
Rainscreens are a common exterior cladding used in the design of contemporary research labs. Because the insulation typically lies behind the cladding and ventilated cavity, but before the supporting stud or structural wall, the rails, hat channels, Z-girts and clips required to support that exterior rainscreen all become thermal bridges. Typically made of highly conductive aluminum, continuous supports such as Z-girts were observed to decrease the R-value of the assembly by 45 to 60% from the design-intended R-value. Rainscreens that employed discontinuous supports, like clips, showed a significant improvement in thermal performance, though the R-value was still determined to fall short of the theoretical design value by 15 to 25%.
Because supports like Z-girts are so widespread in commercial construction today, and have been noted in the industry as common thermal bridges, a number of manufactures have developed alternative solutions. These thermally broken, off-the-shelf products have been developed to meet the structural requirements to transfer the load of the exterior cladding, while not allowing continuous aluminum to pass through the insulation. By limiting the penetrations to only screws and fasteners, and providing insulating pads between metal attachments, we can now achieve the elusive goal of providing continuous insulation. Based on our heat flow simulations, these thermally broken support systems allow a wall to achieve an R-value that is only about 5% less than the clear wall R-value. While each manufacturer has their own strategy deterring the flow of heat, the options that exist give designers the opportunity to find the rainscreen attachment system that works best for their project conditions.
The significant impact observed from thermal bridging suggests a more substantial problem than simply one of condensation risk in a humidified lab environment. The data collected thus far shows that thermal bridging can easily double the conductive heat transfer over what was intended for the design. As we strive to reduce air change rates within the lab environment, we are seeing that envelope heating and cooling loads are an increasingly significant portion of the building energy demand. This research shows that thermal bridging already has a significant impact on the performance of our buildings, and that controlling this path for heat transfer is the key to achieving to truly high-performance façades.
Not surprisingly, the majority of the typical problems identified in this research have centered on transitions between systems and the structural assemblies necessary to support exterior cladding. While many building products exist on the market and it’s easy to implement alternative designs that improve thermal performance, it’s clear that not all manufacturers are equally sensitive to the magnitude of the problem and marketing material must be scrutinized carefully. As we seek to achieve higher-performing research buildings, careful attention and analysis is needed during design to minimize thermal bridges and deliver buildings that perform as anticipated.
1. Morrision Hershfield. (2011). “Thermal Performance of Building Envelope Details for Mid- and High-Rise Buildings” (ASHRAE 1365-RP). Atlanta: ASHRAE Technical Committee 4.4.
2. Madding, R. (2008). “Finding R-Values of Stud Frame Constructed Houses with IR Thermography.” Inframation 2008 Proceedings vol. 9. Reno.
Charles Klee drives Payette’s Research and Innovation Initiative, bringing a detailed understanding of emerging building science and sustainable technologies. Andrea Love leads Payette’s sustainability initiatives. Combining her background in architectural practice and building science, she provides sustainable design knowledge and energy expertise.
Switchable technology has revolutionised the way we see window privacy.
From offices to homes, windows are a widely known architectural device used to bring a number of benefits to a room that would otherwise see isolation from the outside world.
One such benefit is the wonders of natural light; a traditional window brings a snapshot of the outside world indoors without exposing the occupants to the elements.
As the differences in artificial and natural light are generally understood to impact mood, productivity and health, a source of natural light in a room is an important consideration for designers, architects and occupants.
However, with these considerations come inevitable complications in the form of privacy. The bigger the natural light source supplied, the bigger the requirement for a privacy solution.
Traditional solutions used to solve this privacy burden usually come in the form of blinds or curtains. Often, these solutions bring with them even more complications, requiring the designer to source a solution that meets all the specified requirements, which isn’t always easy.
For example, coverage inconsistencies in blinds may allow sections of light to spill into the room, creating an irregular light level in the room.
Furthermore, it is well known that blinds and curtains bring with them more operational maintenance than many would like; gathering dust, tangled cords, sun damage and even the basic yet unproductive time wasted in opening / closing them.
Switchable technology solves these problems, as well as bringing new and exciting aspects to window privacy. For example, being able to control your window privacy using an RF remote control from up to 25m away is an efficient novelty that you will become very comfortable with.
Unlike the slow and often noisy motors used in remote controlled blind or curtains, our switchable products change in an instant without drawn-out mechanical humming.
Available from Intelligent Glass in the form of either a retrofit self-adhesive film or a rigid glass screen, these core technologies have been integrated into various products that allows Intelligent Glass to proudly boast one of the most diverse ranges of switchable solutions in the world.
Our switchable products work by changing the state of transparency from frosted to clear using electrically charged PDLC crystals.
When the electric charge is passed through the PDLC layer, the crystals polarise, causing them to change state from frosted to clear. This offers clients an incredibly powerful privacy tool that not only looks stylish but can also satisfy a variety of additional requirements.
The versatility of switchable technology is one of the areas we see it excel and due to the nature of PDLC film, Intelligent Glass is able to use its clean room facilities to manufacture a range of switchable products with specialist options, such as sound insulating glass, double glazed units, fire resistant glass or even bi-fold door options.
Switchable technology also has the ability to be integrated into smart home and office applications, putting users more in touch with their environment than ever, allowing them to change the window from frosted to clear by a simple voice command.
What’s more is that many of our switchable products can be combined with both rear projection and touch screen technology, serving a multitude of possible commercial and corporate requirements, but also offering the opportunity to dream up creative and exciting residential applications.
For example, a switchable glass rear projection screen can be used incredibly effectively in a shop window display for merchandising or even as part of a glass partition, creating an innovative presentation screen in an office environment.
But in residential applications, we have seen specialist switchable products vary from switchable glass stairs to gaming projection glass partitions.
It’s clear that for window privacy, switchable technology is the future solution that will eventually replace the messy, high maintenance and archaic privacy solutions we see today.
But for now, you can invest in switchable technology safe in the understanding that it is a highly impressive aspirational product; that is, not many people are familiar enough with it to be expecting it in your property.
So when you make that switch in front of your guests for the first time, you are sure to make a big impact. Not forgetting, of course, the ways in which switchable glass will change your daily life for the better.
Window privacy is an aspect that impacts almost everyone, so it’s important that it is considered appropriately.
The SC95 sliding window and door system from Auk is a superior, high performing sliding solution with aesthetics and design appeal. The product comes with sturdy rollers tested for many cycles of operation and a trusted and proven AluK product worldwide for decades.
This versatile sliding window solution comes with lot of choices and customized options and is an ideal lifetime sliding solution for tropical and hot climate applications in high-rise buildings, individual residences and commercial establishments.
■ SC95 sliding system is based on non-insulated profiles. The thermal break insulated profile option is available in SC95TT.
■ A 95 mm frame in two track and 143 mm frame in three track, single and double glazed slider with 85 mm interlock profile at centre. Slimmer option of 55 mm interlock is also available.
■ SC95 comes with a glazing bead based solution; hence convenience in glass interchangeability for users.
■ Superior aesthetics with international design appeal: 45 degree join for sashes and 90 degree join for frames.
■ Well-designed sloped bottom track with effective drainage solution.
■ Anodized rail on bottom track for extra smooth sliding.
■ Solid and robust in performance works for very high design wind pressure; a thoroughly tested window system for demanding weather criteria of tropical zones. A tested and certified product as per EN norms for air/water/wind.
■ Possibility of fixed light, fly screen/casement integration.
■ All accessories, fittings, gaskets are AluK branded and tested for performance.
■ Value added features like perimeter gasket for added protection at edges of the window application surface.
■ Single, multipoint locking with flush spring locks, thumb pull lever locks or cremone handles for convenience of usage.
■ This system is adapted for large dimensions with sash weight up to 160 kg of load bearing capacity per sash.
■ Infill glass can be single or double glazed (thickness can vary from 6 to 24 mm).
Steel-free Schüco LivIng Alu Inside window system with patented aluminium profile rolling technology for the best thermal insulation efficiency (Uf value of 0.87 W/m²K) | Image: Schüco Polymer Technologies KG
The new Schüco LivIng Alu Inside PVC-U system allows steel-free windows suitable for passive houses to be produced economically on an industrial scale.
The weldable EPDM rubber gaskets rolled in the factory have excellent recovery properties, guaranteeing the best weathertightness and ensuring the windows have a long service life. Schüco is currently the only systems provider with this sealing technology, purchased in Germany from Semperit.
Patented aluminium profile rolling technology
Schüco LivIng Alu Inside does not require any steel reinforcement. Instead, the company uses its tried-and-tested and patented aluminium profile rolling technology, whereby continuous aluminium strips are simultaneously extruded into PVC-U profiles.
They provide the entire construction with a level of stability which almost rivals that of steel-reinforced profiles. It also has excellent heat reflection and can be easily recycled. Prior to welding, the aluminium insulating bars can be milled back simply and quickly using an insulating bar milling machine.
No time-consuming screw fixing for steel reinforcements is necessary. All other fabrication steps are carried out in the usual way and using conventional production facilities. The lack of steel reinforcement also has a positive effect on the unit assembly: the units are lighter and therefore easier to handle.
As this construction is part of the Schüco LivIng system range, fabricators can combine it in a variety of ways and make use of a number of identical main and accessory profiles as well as the matching range of aluminium cover caps.
Weldable EPDM gasket
In close collaboration with Semperit, Schüco has developed and launched the first weldable EPDM gasket for window and door systems. Even after welding, the gasket remains elastic and soft in the otherwise critical corner area, creating a permanent sealing effect.
The fabrication of PVC-U profiles is also made considerably easier by the simultaneous welding of the gaskets. The EPDM gaskets, which are UV-resistant and stable in cold temperatures, provide permanent elasticity for all climate zones in temperatures ranging from -40 to +120°C. Semperit has been granted the patent for this technology.
The 7-chamber profile construction, the dispensation with steel reinforcement and the specific positioning of the aluminium hinges mean that Schüco LivIng Alu Inside has no thermal bridging.
The centre gasket system with three drainage levels, optimum division of the chambers and its large-volume additional insulation zones for the optimum accommodation of insulating blocks achieves excellent thermal insulation (Uf value of 0.87 W/m²K) – making it suitable for passive houses in accordance with Dr Feist (Uf value of 0.79 W/m²K).
The optimised rebate base geometry allows the optional use of additive adhesive technology. For special design requirements, the system is available with a solid-grey base material. The construction can be coloured with external Schüco TopAlu cover caps, the metallic colours of Schüco AutomotiveFinish and a wide range of foils.
Energy-saving windows in the Schüco LivIng Alu Inside profile system range are 100% recyclable. The PVC-U and aluminium materials are recycled by Rewindo GmbH and used for the manufacture of new profile systems.
The market launch of Schüco LivIng Alu is scheduled for September 2018.
Schüco Polymer Technologies KG presented Schüco LivIngSlide, its new PVC-U lift-and-slide door system, at FENSTERBAU FRONTALE 2018 in Nuremberg.
Designed for demanding requirements with regard to stability, joint weathertightness and watertightness, the system features rolled and weldable EPDM gaskets as standard. Fabricators benefit from quick and easy fabrication and installation. The vent frame, for example, can be fabricated by machine in a processing centre.
Patented sealing technology
The unique feature of the new Schüco LivIngSlide lift-and-slide door construction is the weldable and rolled EPDM glazing gasket in the vent frame which comes as standard. It combines the advantage of long-term weathertightness which is typical of EPDM gaskets with the weldability of, for example, TPE gaskets.
This creates a continuous gasket frame with soft inner corners even after the welding process – with increased watertightness in the corner areas and a closed corner design. The top-quality material retains its high sealing effect throughout its useful life.
It is UV-resistant, stable in cold temperatures and suitable for use in all types of buildings and climate zones, offering permanent elasticity in temperatures ranging from -40 to +120 degrees Celsius.
Schüco is currently the only system provider to offer its customers such a high-quality EPDM gasket rolled as standard. Schüco first presented the sealing technology, developed with Semperit for the Schüco LivIng system platform and since patented by Semperit, at Fensterbau 2016.
Schüco LivIngSlide is based on a 6-chamber vent profile construction. With a vent basic depth of 82 mm, the system achieves Uf values to 1.2 W/(m2K). In a white design, unit sizes up to 6500 mm wide and 2600 mm are possible – taking into consideration the maximum vent weight of 400 kg.
The stability of such large-format constructions is achieved with steel reinforcements in the vent frame, designed as closed rectangular tubes. Moving and fixed vents can be combined to make easy-to-operate two, three and four-vent units, and designed as one or two-track sliding systems.
A roller carriage support is used for secure centring and fixing, guaranteeing easy operation. Depending on the vent types, burglar resistance up to RC2 is possible. With a frame trim basic depth of 194 mm, the system is suitable for newbuilds and renovations in any climate zone.
Added value for fabricators
Schüco LivIngSlide is integrated in the Schüco LivIng range and therefore compatible with the window and door system of the same name. Fabricators can therefore use a large number of identical accessory articles, such as glazing beads and other glazing accessories. Using a processing centre allows for efficient vent fabrication.
Fabricators also benefit from additive adhesive technology and glazing beads that vary by 2 mm in their strength. This means that glazing from 24 mm up to a maximum of 52 mm, and therefore special glazing as well, can easily be precisely accommodated, without having to switch the glazing bead gaskets. This saves fabrication time.
The stable, closed vent cross section, which does not require stabilising additional measures, also helps shorten fabrication time. The subsequent installation is made simpler by connector kits with moulded parts, among other things.
This reduces the amount of sprayable sealant and simplifies fabrication considerably. Fabricators can also order the profiles cut to the optimum length with the right fittings and handles as a complete package from a single source at Schüco.
In terms of colour, the profiles can be designed with a wide range of foils, the exclusive Schüco AutomotiveFinish surface finish technology or the clip-on Schüco TopAlu aluminium cover cap.
The system is scheduled to be available at the end of 2018.
Roof Maker’s new Passive House Flat Rooflight has set a new standard in energy efficiency.
The rooflight is the first in the world to achieve the prestigious Passive House standard and to receive accreditation from the Passivhaus Trust.
If you’re wondering what all this means and how it could benefit your property, read on.
What is Passive House?
Passive House is an aspirational standard of energy efficiency, designed to dramatically reduce a building’s ecological footprint.
The standard originated in Europe, back in 1988. Its name comes from the German term, Passivhaus. The first Passivhaus residences were built in Germany in 1990.
The Passive House standard
Achieving the Passive House standard is no mean feat. To do so, a product must pass rigorous testing and meet strict criteria.
Two of these criteria are that the building must:
Prevent heat loss, achieving a set limit on the amount of air that can leak out
Maintain a comfortable temperature, achieving set limits on its heating/cooling requirements
The importance of Passive House
Passive House standards:
Keep your energy bills to an absolute minimum
Reduce your CO2 emissions by reducing your use of fossil fuels
Help to counter the threat of climate change
Save our limited natural resources, giving us more time to find renewable alternatives
The cost of installing Passive House elements is generally outweighed by their energy saving potential.
Roof Maker is a world leader in green innovations
Since 2001, Roof Maker has been designing innovative, contemporary products that combine outstanding energy efficiency with timeless style.
To avert climate change, we understand the need to cut carbon emissions and conserve our precious natural resources. While UK Building Regulations have tightened to meet these ends, we have always strived to do better.
Through ongoing research and development we have created products that far exceed the requirements of the Building Regulations, offering superior insulation and significant energy savings.
Meeting the Passive House standard with a rooflight is a world first and a momentous achievement. It is also a huge step forward in the development of housing that is healthier for its occupants and the environment.
Impressively the rooflight has achieved Passive House standard with a three-pane triple glazed unit, rather than the four or five panes you might expect. Keeping the number of panes to a minimum results in a lighter unit that transports easily and is quicker to fit.
Listening to our customers
At Roof Maker we work closely with our customers, using your feedback to continually research and develop better products.
When it comes to rooflights, you have told us you want:
To increase the natural light in your home
Classic designs that will suit your property — whether it’s old or new
Glass that is easy to keep clean
A manageable unit that is quick and easy to fit
A built-in upstand, prefabricated to the optimum angle
A durable product, guaranteed to last
But you don’t want:
Your heating bills to increase
Your rooflight to create a ‘greenhouse effect’ in hot weather
Chunky frames that collect dirt and obstruct the light flow
Sun damaged fabrics and furnishings
The Passive House Rooflight fulfils all these criteria.
Benefits of the Passive House Flat Rooflight
The Passive House Flat Rooflight:
Features a contemporary frameless design to let in more natural light
Offers exceptional insulation to prevent heat loss, draughts and condensation
Retains the warmth from your heating appliances in cold weather
Keeps your heating requirements and bills to a minimum
Has Solar Control to keep your room cool and comfortable in warm weather
Blocks harmful UV rays and prevents your furnishings and fabrics from fading
Has a self-cleaning coating, which reduces the need for manual cleaning
Is triple glazed for a lighter, more manageable unit that can be moved easily
Has a built-in upstand for quick and easy fitting
Carries an industry-leading 20-year unit seal warranty and a 10-year guarantee against frame discolouration, cracking and shape deterioration
Energy saving potential
Like many Roof Maker products, the Passive House Flat Rooflight is triple glazed as standard. The unit comprises three 6mm panes of glass, separated by argon-filled cavities.
Research has shown that replacing single glazed or old double glazed units with triple glazing can cut your energy bills by 50%, if your home is properly insulated.
Find out more
Roof Maker is a world leader in the design, manufacture and supply of high quality rooflights and bi-fold door systems — including the new Passive House Flat Rooflight.
Our premium glazed products are designed to transform your living space into a bright, comfortable and energy efficient space you will enjoy for many years to come.
Impelling window profiles not only to look like wood, but also feel like it too.
Cool and cosy. At first glance these current design trends seem contrary to each other. But behind the words the two senses, touch and sight, are currents which move slowly and steadily closer. Impelling window profiles not only to look like wood, but also feel like it too.
RENOLIT developed the three-dimensional VLF emboss to realize desire for greater authenticity. The dynamic deep grain structure displays a brushed and sandblasted surface. The surface finish is linear and uniform, and despite its contoured structure it is also very robust.
“We combined the matt and even feel with proven scratch resistance”, confirmed Franz Josef Weber, Product Manager in the RENOLIT EXTERIOR business unit.
Natural and refined
VLF has a very natural appearance and is therefore in keeping with current hardwood trends. Since the popularity for oak designs is unwavering, the company will be presenting the new emboss in four different oak designs at Nuremberg.
The light “Ginger Oak” woodgrain embodies the natural wood concept, whilst the dark “Amaranth Oak” occupies the other end of the colour scale. Somewhere in the middle lies “Honey Oak”, a woodgrain that radiates a special warmth, whereas the light grey sheen of the bleached “Weissbach Eiche” appears more distant and restrained.
Common to all designs however is their authentic appearance and a subtle silver shimmer that varies with perspective, which sheds a noble kind of light.
When combined with solid colours, VLF is a stylish accompaniment to modern architecture and reminiscent of freshly painted solid wood. At Fensterbau Frontale, six popular plain colours were on display with this emboss, for example White, Cream White, Dark Green, Grey and Anthracite Grey.
In contrast, the flat matt emboss “Ulti-Matt” is strikingly stylish. “A gloss level between 1.0 and 3.5 gives the surface an almost sanded appearance.” Leon James, Product Manager at RENOLIT’s UK manufacturing site, is responsible for its development.
Produced in RENOLIT EXOFOL PX high-performance film grade, it provides an alternative to powder coating. Ulti-Matt’s appeal was displayed in conjunction with white, cream and anthracite grey and with the new real “Black”. This exact black is also available with the modern VLF and classic woodgrain textures.
The presentation of the new product introductions broke new ground at this year’s leading trade fair. As an oversized simulation the various colours were demonstrated in combination with façades and window profiles.
RENOLIT also presented a selection of nine new colours and woodgrains live in product pillars. Carefully lit, the visitor was able to see the original patterns in all their details.
Professional Corner Pen from the original film manufacturer
The launch of the RENOLIT EXOFOL Professional Corner Pen, a small but important tool for window manufacturing was celebrated at Nuremberg. Using the pen, imperfect welds and mitre joints can be precisely matched to the colour of film-laminated surface.
“With our service products, as the original film manufacturer, we offer customers additional reliability” says Harald Neunzehn, head of the RENOLIT Film Service, which also distributes the RENOLIT EXOFOL Professional Cleaner. It is such attention to detail that has contributed to the original foil manufacturer’s success.
Architecture began to be substantially impacted by the development and the opportunities of glass manufacturing at the time when glass production became affordable, i.e. with the advent of float glass processes, which made it possible to produce glass in larger sizes.
Over the last few years there has been quite an Olympic size contest among glass manufacturers. Lengths up to 18 metres are now feasible, and one company already has its sights very firmly on the 20-metre mark for 2018. Glasses in XXL sizes can still only be found in selected projects – and of course at glasstec 2018 in Düsseldorf.
For a long time, whenever the issue of transparency was discussed in architecture, expertise and technology in glazing were measured in terms of the most efficient U-value.
And it’s certainly true that, over a period of 50 years, it has been possible to move from single glazing through the first generation of insulation glass to today’s triple thermal insulation glazing.
This has reduced the Ug value from over 5.0 W/(m2K) to 0.7 W/(m2K), bringing it down to almost one tenth. However, the contest for the most efficient heat insulation in thermal glazing has more or less come to an end now.
Although further improvements are technically possible through quadruple or vacuum glazing, they involve so much more effort and costs, and they have so many other functional drawbacks that they cannot currently cover the full range of the market. They seem unlikely to gain much ground in the future or to be genuinely worthwhile.
Glass has increased in size
However, the heat insulation of glass is only one aspect among many that play a role in architecture. We only need to remind ourselves of fire and sound protection and shading – a feature which can now be handled by the actual glazing, thanks to electrochromic (switchable) glass.
It involves no mechanical components such as external Venetian blinds or external roller blinds, which are often susceptible to malfunctioning and can no longer withstand wind impact at high altitudes.
And where superlatives are concerned, glass sizes are currently a much discussed issue in the glass industry, moving away from the significance of glazing for architecture as a purely practical matter and focusing more on aspects of design and aesthetics.
We might even say that glazing has become a big issue again – gaining quite literally in size. With active support from planners – though also challenged by them – glass manufacturers are now engaged in a fierce contest that will decide who eventually succeeds in manufacturing, processing and finishing even bigger glasses.
The glass manufacturers that are currently setting the tone for what is feasible in the development of XXL glasses are Sedak, along with Thiele Glas, AGC Interpane, Saint-Gobain and others. Each of these companies is now able to produce 18 × 3.21 metre glasses, though Sedak is already envisaging 3.51 × 20 metres from the middle of 2018 onwards.
They will then be manufacturing and finishing “the biggest glasses in the world”. And as such over-sized glasses somehow need to be transported from A to B, Sedak – a glass finishing company founded in 2007 – has developed a special inloader for this purpose. It can put 16-metre glasses on the road and is probably the longest HGV semitrailer for glass, with a total length of 23 metres.
Structural stability and logistics – the challenges of XXL glasses
In reality, the manufacturing of XXL glasses is only one side of the coin. Finishing and logistics are equally important and therefore need to be resolved and mastered.
After all, XXL glasses go through just as many manufacturing stages – from the float glass bed to installation at the construction site – and just as many finishing stages as normal-sized glasses.
The dimensions of such glasses only differ with regard to thickness (6 to 20 mm), while the process as such is the same as for any other sizes. However, things get trickier when it comes to ensuring structural stability in a given building.
This is because mounting devices, load-bearing sections and surfaces must be able to bear the enormous weight of the glasses (between two and three tonnes, depending on size) and also cope with wind and perhaps snow.
And of course there is another issue that needs to be resolved: once a large glass has reached the construction site on a truck, it needs to be transported to its final destination without the risk of damage or indeed total destruction.
New technologies in glass processing and finishing
Depending on each customer’s preferences, the finishing of XXL glasses involve the same stages as any other glass: processing (i.e. cutting, drilling and edge treatment), pre-tensioning (partial toughening, safety tempering and heat soak testing), ceramic printing (web-feed and digital printing), coating and laminating.
Glasses up to a length of five metres can even be bent in a furnace. If glasses are very large, cold-bending methods are applied, with a limited minimum bending radius (1500 x glass thickness, for example, a 12-metre radius for 8-mm glass).
This shows that the parameters and therefore limits in using XXL glasses are set not only in production, but also by the further processing and finishing of such glasses. AGC Interpane and Sedak, for instance, are currently both in a position to make multi-pane thermal glasses up to 3.21 x 15 metres. Larger sizes can only be achieved for mono glasses.
Robust edge seals and switchable glasses
Alongside finishing, logistics and installation, with XXL glasses, the focus is also on edge seals and sun protection. At least one edge is limited to a length of 3.2 metres, so that the deadweight for larger glasses increases disproportionately on the narrow side, due to the manufacturing process.
Depending on the mounting of the glass onto the façade, the bond on the edge seal must achieve far more to ensure structural stability and to satisfy the need for impermeability. Unlike structural stability, the energetic relevance of the edge seal decreases in proportion to the increase in glass size.
This is because the thermal bridge impact of the seal is reduced in relation to the surface area ratio. On the other hand, it is all the more important to have a reliable and efficient sun shield. Under conventional construction, e.g. with external blinds, this is virtually impossible with large glasses and particularly at high altitudes.
Another aspect is the aesthetic element: It is counter-productive to emphasise the transparency of a building through the use of oversized glass, if the windows are then hidden behind blinds. Although the heat input can be noticeably reduced through low emission coating, the glare from bright sunshine still remains unresolved if no shade is provided.
For XXL glasses it seems that switchable glazing – offered, for instance, by Saint Gobain under the brand name SageGlass – is virtually predestined as a smart solution to address all three issues: glare, aesthetics and wind load. The cost of energy (Sageglass: 2.4 W per square metre) is almost negligible, considering the money saved on the installation and maintenance of blinds.
The result is that you can always see out of the window, as the view through the glass is never obstructed in any way, even when the glass is dimmed. Switchable glass technology makes it possible to trigger the tint either actively or passively.
The most promising solution is currently the active electrochromic variety (e.g. EControl glass) with internal nanostructured coating. The glass turns blue when a low voltage is applied, creating the so-called “electrochromic effect”.
Impressive references as a testimony to expertise
For a glass manufacturer references are the best form of advertising. References not only show the outstanding architecture that can be achieved with XXL glasses, but also how much expertise is required in the implementation of such projects.
One example is the replacement of the 45-year-old glass façades of the UNCTAD building, the United Nations Conference on Trade and Development, in Geneva. They are 13 metres high and made from non-tempered glass, unusual for 1971. They were probably the largest glasses ever used up until then.
The 15-metre glass façade panes for the new Apple headquarters in Cupertino were another sensation. Such projects do of course arouse ambitions among architects and image-conscious companies, and we can safely assume that Sedak’s 20-metre achievement won’t mark the end of the development and manufacturing of XXL glasses.
Experience multifunctional XXL glass formats for yourself at glasstec 2018
The performance of glass manufacturers and finishers is measured against the challenges of modern glazing posed by principles of aesthetics, design, energy efficiency, functionality, comfort and construction.
There are now specially cut, curved and bent glasses, glasses with striking printing, glasses that can be dimmed as little or as much as required, and indeed glasses of hitherto unparalleled dimensions.
This illustrates the enormous diversity of today’s glass processing. As a result, glass has gained a prominent position as a building material in architecture. glasstec 2018 represents today’s know-how of the glass industry and showcases its visions for tomorrow and beyond.
Extrudaseal are delighted to have launched their new aluminium bi-fold lock-housing mechanism and cover system.
Developed in response to fabricator demand, this rigid PVC-U extrusion delivers an exacting and flush fit inside the sash frame, minimizing adjustment of locking mechanisms. The specially designed cover system comes with easy to fit Eurogroove casing suitable for alumininium bi-folding door systems.
Paul James, Sales Director at Extrudaseal explained: “In developing a lock-housing which sits flush with the frame but most importantly tight within it, we’re able to eliminate any movement.
“The major innovation is that the housing features two additional legs, which reinforce and deliver far greater structural integrity to the profile.
“When its fixed within the frame with fixing screws there’s no movement whatsoever and because it’s also flush with the frame it’s also far less likely that you’re going to have to adjust the operation of the lock.”
The new lock-housing is available from Extrudaseal in black, white and anthracite grey, the latest in a line of new products from the components specialist.
Extrudaseal has manufactured more than 10,000 km of gaskets in the last year, alongside weather seals, Glazepta tapes and U-channels, pressure plates, box sections and bi-folding door seals for leading systems.
This includes manufacturing gaskets for a wealth of aluminium systems, including Smart, ALUK, Metaltech, Senior and Ikon, amongst others.
Suitable for retrofit and use with a wide range of leading aluminium systems including ALUK, like the new lock housing, it was developed by ExtrudaSeal’s in-house design team, specifically in response to installer and fabricator demand.
“We have a track record of product development. We’re a specialist manufacturer and our focus is on developing designs which lever additional advantage to our customers, while also reducing their cost”, said James.
“We have our ear to the ground, listen to what our customers are saying and work closely with them to develop products which address their specific concerns or deliver new opportunity.
“The development of our new lock-housing epitomises this approach”, he concluded.
Schmalz has developed the system especially for CNC machining centers made by Bystronic.
Schmalz has revised its proven SQC vacuum clamping system for glass machining and made the design much more streamlined. This makes use on Bystronic glass grinding machines even simpler. Thanks to the quick-change system that can be operated without tools, setup times are significantly reduced.
Schmalz has developed the system especially for CNC machining centers made by Bystronic. This allows grinding of glass workpieces, for example designer and automotive glass on all sides. The clamping system consists of the suction cup mount (base), the suction cups and the covers for the unused vacuum connections.
The cover protects the connections and mechanical parts of the change system from contamination. When changing workpieces, users can retrofit the system very quickly: The base is fixed with a hollow bolt and can remain permanently on the machine table.
The suction cups can be easily attached, to remove suction cups only one push button must be pressed. The covers are also effortlessly attached and can be locked in a similar way to a bayonet fastener. Additional tools are not required.
The new Schmalz system is also very flexible: Depending on the glass geometry, the user can now choose between square and round suction areas. As a result, the Bystronic machines can be retrofitted on a one-to-one basis with Schmalz suction cups.
Due to the slimmer shaft of the aluminum housing below the suction area, the suction cups can be placed closer to the processing edge. The machining becomes even more precise and low vibration. Mixed operation with original suction cups and Schmalz suction cups is also possible.
The cups installed on the machine table suck in and fix panes of different geometries. Smooth machining and peripheral grinding is possible as a result. Users produce very precise and dimensionally stable parts.
An abrasion-resistant coating allows the absorption of high lateral forces between the suction cup and the glass part. The workpiece always remains securely in position even with strong lateral forces.
Glass sheets are handled particularly gently. Incorrect clamping can quickly lead to damage and expensive waste. In order to prevent this, Schmalz makes the interchangeable sealing frames of its system with the material HT1, which leaves very few marks.
Tvitec fabricated more than 2.000 sqm of different architectural glass solutions.
Uría Menéndez is considered one of the most prestigious lawyer’s offices in Europe. Over a thousand people are working at their offices worldwide. Their new headquarters, in line with the firm’s prestige, will have a truly iconic design right in Madrid city centre (Spain).
The glass has transformed the façade of an old building at 42 Suero de Quiñones Street, both in terms of aesthetics and energy efficiency. Tvitec has supplied the glass panes for the entire building envelope, with high performance solutions and including about six oversized units, clearly visible on the main façade.
These large glass panes, 10m long by 3m wide, top the whole façade, designed by the renowned Rafael de La-Hoz architect office. Tvitec has shown on this project their capabilities in laminating extra-large glass panes.
Each unit has been laminated by using SentryGlas interlayers to improve the safety and soundproofing of the building envelope. In addition, all lites were toughened and heat-soak tested, and digitally printed with a white pattern that creates a unique design of high durability.
Altogether, Tvitec supplied more than 2,000 sqm of several different solutions in high quality architectural glass. The inner skin of the façade is made of insulating glass units which serve as a support to the above mentioned large units, among others, smaller, located on the side parts of the building.
This is the way Tvitec’s high performance and eco-efficient architectural glass contributes to the bioclimatic façade that the architects designed in order to assist the natural ventilation in Summer and keep the heat in Winter. For the 10m units, barely available in Europe but through Tvitec, the design team chose Planitherm XN II (Saint Gobain) on low-iron.
In addition to the sustainability that Tvitec’s architectural glass provides, the lamination process enhances the safety and soundproofing properties of the glass as this building is located in a really central and noisy part of Madrid.