FAQs

Acoustic performance: absorption

Nowoflon ET can be specially treated to absorb reverberations in buildings, while still remaining transparent. The state-of-the-art solution for building renovation is extremely cost efficient. Please contact us for more information.

Acoustic performance: insulation

There are various studies on the acoustic performance of ETFE film installations. As ETFE is not a barrier to sound, it improves the acoustics in all buildings, especially public buildings. Please contact us for more information.

Building Research Establishment Environmental Assessment Method (BREEAM)

Developed in the UK, BREEAM is a leading method for assessing the sustainability of infrastructure and buildings. Nowoflon ET is certified according to BREEAM standards.

Cable pockets

Cable pockets are slightly similar to cedar pockets but are used to support the ETFE structure on large-span structures or facades. They are used to cover the steel ropes providing mechanical support.

Cable-supported structures

Tensile membrane structures are most often used as roofs, as they can span large distances economically and attractively.
Cable-supported structures are tensile membrane structures supported with steel cables underneath the cushion in order to withstand large spans.

Cedar

Usually a rod used to fix any product in a frame. The cedar is welded into an envelope seam. Most common way to install ETFE.

Clamping

Used whenever it is not possible to weld two or more panels, fabrics or different plastics together. The various elements are typically clamped together using metal plates, screws and bolts.

Cleaning and maintenance

Due to the non-adhesive surface properties of ETFE, deposits of dirt, dust, and debris do not stick and are washed away by rain, resulting in a self-cleaning effect. However, as for all mechanical equipment and components, we recommend an annual inspection. The inspection should include all necessary checks on the air inflation units and filter replacements.
Please refer as well to our cleaning and maintenance instructions.

Cost efficiency

Due to the lightweight nature of ETFE, substructure support systems and concrete foundations can be designed more efficiently. ETFE systems also provide ample natural daylight, thus minimizing energy costs by lowering the demand for indoor lighting. ETFE is therefore a highly cost-effective solution.

Design

Making the most of ETFE’s performance characteristics requires interaction between many geometric forms, materials and tensioning elements. Design can be aided by sophisticated software to help architects and engineers create almost any structure imaginable.
ETFE structures are generally specified as design-build projects. When designing the structure, the geometry needs to be addressed first. Next, testing how the membrane will interact with the support structure helps determine how to meet the load requirements. Throughout the entire design-build process, coordination is critical to the structure’s overall aesthetics and performance.

Durability

Membranes last longer than conventional roof materials. Many of the oldest Nowoflon ET installations, dating back more than four decades, continue to look and perform perfectly today. Many professionals consider ETFE film as one of the most durable products in the whole industry. ETFE does not degrade when exposed to environmental pollution, UV light, harsh chemicals or extreme temperature variations, making it a highly durable material.

E-modulus

Also called the “young modulus”.
Originally used in metallurgy, it describes the “elasticity” of a product. The higher this factor, the greater a product’s resistance to external forces.

ETFE architecture

ETFE (ethylene tetrafluoroethylene) was originally developed by DuPont over 40 years ago as an inert coating material for the aerospace industry. ETFE film, then conventionally used in agricultural applications such as greenhouses or for the coating of solar cells, has since demonstrated its worth in the architectural sector as well. The first application in the building industry took place in the early 1980s in Europe. The Eden Project in Cornwall, UK, demonstrated the tremendous potential of ETFE. ETFE film gained recognition applied on major projects around the world. It is now considered the premium material for transparent cladding applications in roofing and facade construction.

ETFE cushion

In a double or triple-layered application, ETFE film incorporates a pneumatic system to maintain air between 2, 3, or more layers of film attached in aluminum extrusions and supported by a lightweight structure, creating inflated cushions. These cushions are filled with low-pressure air, providing thermal insulation and structural stability against wind or snow loads. If needed, small cables can be used for reinforcement.

ETFE film

ETFE (ethylene tetrafluoroethylene) film is durable, highly transparent and very lightweight in comparison to glass structures. ETFE is considered the material of choice for traditional skylight applications, long-span structures and building facades. The raw granulate is extruded into sheets called foil or film with a density of 1.012 oz. per cubic inch. Due to the low coefficient of friction of its surface, dust or dirt will not stick onto the film. As the film is UV transparent, it will not discolor or structurally weaken over time. ETFE can also be fully recycled.

Ethylene tetrafluoroethylene

The full name for ETFE.

Fire resistance

Nowoflon ET is certified according to all major national and international fire certifications such as ASTM, NFPA, DIN, EN and BS, as well as GOST and NFTS.

German Sustainable Building Council (DGNB)

The DNGB (Deutsche Gesellschaft für Nachhaltiges Bauen) is a German non-profit organization dedicated to developing and promoting sustainable building projects. Nowoflon ET is certified according to DGNB standards.

G-value

The total solar heat transmission through transparent and translucent materials is equal to the solar energy that is transmitted through the material directly, plus the solar heat that is absorbed by the material and then re-emitted into the enclosed space. The difference between G-values and solar heat gain coefficients is that they use a different value for air mass.

German Sustainable Building Council (DGNB)

The DNGB (Deutsche Gesellschaft für Nachhaltiges Bauen) is a German non-profit organization dedicated to developing and promoting sustainable building projects. Nowoflon ET is certified according to DGNB standards.

Haze

Describes the “cloudiness” of a transparent product. The lower the haze factor, the better the transparency.

IR-CUT

IR-CUT is the latest development in the Nowoflon ET family.
It is an ETFE film that absorbs infrared rays, the part of transmission that causes the heating effect in a building.
Tested by the independent IFT Institute in Germany, it is possible to reduce the G-value from 0.71 to 0.41 by exchanging only the outer layer of a 3-layer cushion, while still remaining 100% transparent.

Leadership in Energy and Environmental Design (LEED)

LEED is one of the most widely used rating systems in the world for sustainable buildings, developed originally by the U.S. Green Building Council. For more details please see “sustainability”. Nowoflon ET is certified according to LEED standards.

Life cycle assessment (LCA)

The LCA is an analysis of a product’s carbon footprint throughout its whole life cycle, including transport, recycling, etc.
It assesses values like used water, energy and so on, as per DIN EN 14021

Light transmission

Using ransparent Nowoflon ETFE films helps maximize light transmission into[nbsp]building interiors, thus reducing the costs for electric lighting.

Photovoltaics

Flexible photovoltaic (PV) cells can be mounted on ETFE to generate clean energy.

Pneumatic structures

A pneumatic ETFE cushion structure is generally supplied by one or more inflation units. Each unit consists of two redundant blowers forming a backup system for guaranteed structural stability. The air is dried when it enters the machine to avoid condensation within the cushions. A series of pressure sensors continuously monitor the internal pressure of the ETFE cushions in order to maintain it. Sensors can automatically and continuously adjust the pressure to compensate high wind or snow loads.

Recycling

ETFE is a fully recyclable material. It is also possible to remold waste from the manufacturing process or even old ETFE elements into new ETFE products.

Roofing cushions

Cushions made from ETFE film range from two to four or more layers depending on wind loads and the required insulation, transmission or optical effects.
ETFE roofing cushions are filled with air, using inflating tools which dry the air inside. This is to avoid condensation in the cushions.

Safety

ETFE’s high resistance and elasticity makes it an ideal building material for areas at risk of sudden extreme loads such as earthquakes or blasts. Unlike glass that will shatter and present a major hazard under similar shock load situations, ETFE will deflect under load and is unlikely to cause any major damage even if it breaks.

Shading coefficient

The ratio of solar gain (due to direct sunlight) passing through a material unit to the solar energy which passes through 3 mm of clear float glass [1]. It is an indicator of how well the glass thermally insulates (shades) the interior when there is direct sunlight on the material or cushion. The shading coefficient depends on the ETFE film type and the roof/facade construction. The lower the rating, the less solar heat is transmitted through the material, and the greater its shading ability. Solar properties play a significant role in the selection of the ETFE film type, especially in regions or areas with high solar exposure.

Single-layer ETFE

ETFE can be applied in a single layer form and is reinforced with wire cables, lightweight steel or aluminum to maintain shape and stability.

Solar heat gain coefficient (SHGC)

Solar heat gain coefficient (also known as solar heat gain or passive solar gain) explains the same phenomenon as the “G-value”.

Sustainability

Nowoflon ETFE film, ranging from façade to roofing membranes, can help architects and designers achieve and earn Leadership in Energy and Environment Design (LEED™) and Energy Star project certifications and credits for their latest design projects by increasing building sustainability. Nowofol is a member of the U.S. Green Building Council (USGBC).

Tensile architecture

Tensile architecture refers to a structure that is characterized by a tensioning of the fabric or pliable material system (typically with wire or cable) to provide the critical structural support. When using ETFE film, the material is usually fixed in lightweight aluminum frames and then tensioned by the air pressure.

Tensile strength

The tensile strength of ETFE is the maximum amount of stress that it can withstand before failure or breaking. Please see our technical datasheets for more detailed information.

Thermal performance

As with glass, it is possible to achieve increased thermal performance with a multi-layered system. For a double or triple-layer pneumatic system, multiple layers of film are welded into panels that are inflated with low-pressurized air to stabilize the film and provide the thermal property of the system.

U-value

Overall heat transfer coefficient, also known as U-value, is the rate of heat transfer through a structure (either a single material or a composite), divided by the difference in temperature across that structure. The unit of measurement is W/m²K. The better a structure’s insulation, the lower the U-value.

Welding

Welding is the joining of two or more panels or layers.
Nowoflon ET can be welded using heat contact or impulse welding.