Growers will Benefit from Specialized ETFE Cladding Technology
(Vancouver, BC) – November 9, 2011.
RENERGY Foods AG announced today that it has successfully manufactured and tested several pneumatic ETFE pillows. The prototype ETFE pillows and frames provide proof of concept for the first demonstration biodome, the 30 by 10 meter “MicroDome.”
A total of 26 ETFE pillows will be required to complete the Renergy MicroDome. The pneumatic pillows will serve as the structure’s cladding and will be attached to the biodome’s aluminum frame.
ETFE is a well-studied and widely-used architectural polymer (plastic) with numerous remarkable properties that make it the material of choice to clad Renergy biodomes.
To manufacture the cladding, and using ETFE welding equipment, individual sheets of ETFE are fashioned into air-filled pillows. Growers using Renergy biodomes will see a number of operational and environmental benefits that can be directly attributed to this remarkable material:
- Exceptional solar gain
- A very high heat retention capacity
- Transmission of 95% of all light frequencies
- Possibility of using imprinted shade-on-demand features for climate control
- Full material recyclability
- Fire safety advantages
On balance, growers will see a reduction in construction, operational, and maintenance costs.
Two examples of well-known structures that incorporate ETFE pillows are the “Eden Project” in Cornwall, UK, and the “Water Cube” in the Beijing National Aquatic Centre (2008 Olympic Games).
Each Renergy biodome pillow consists of two or three layers of ETFE foil welded inside a frame. Pillows are inflated with air, typically at a pressure between 200 and 600 pascals. To maintain air pressure, gauges and electronic switches monitor and automatically activate low power electrical fans connected to the pillows (click for pictures).
Renergy is in the process of setting up a manufacturing facility – the first of its kind in North America – dedicated specifically to the production of ETFE pillows. For this purpose, the company has acquired specialized ETFE welding equipment, as well as extremely durable ETFE foil.
More About ETFE
ETFE (Ethylene tetrafluoroethylene) is a polymer with remarkable properties. The material is not a petrochemical derivate and its manufacturing process is water-based, requiring no solvents or additives. ETFE has 95% transmission of all light frequencies. The material weighs a mere 1% of glass, enabling considerable savings on the structure required to support the cladding. The non-stick characteristics of ETFE make it low maintenance and virtually self-cleaning. With a wide service temperature range of between -200° to +150° C, it has extremely good resistance to tearing, weathering, solvents, and chemicals. It is extremely flexible and can stretch 150% to 200% before breakage. Because it is able to absorb shock loading without risk of fracture, breakage, or structural overload and collapse, it is an ideal material where there is a risk of explosion. ETFE has low flammability and is self-extinguishing. In its pillow configuration, it has a U-value of approximately 1.95 W/m2K, which is considerably better than triple glazing.
RENERGY FOODS Canada, Inc.
1 (778) 881- 6190
The following architectual drawings provide various perspectives of the first ETFE Biodome, which is to be called the MicroDome. It is intended to be sold to small and aspiring commercial growers. Its key benefit is to provide a climate-controlled environment which enables stable year-round crop production through the use of pneumatic ETFE pillows. Its small carbon footprint, when combined with the Vertical Growing Cabinet, will provide a cost-effective growing solution.