An ETFE cushion roof is impressive to look at, but have you ever wondered how the cushions maintain their shape, even in bad weather? As part of our quick guide to ETFE we are exploring how the cushions are inflated.

The structural strength of an ETFE cushion system comes from the air pressure which the membrane is kept under. As a result, each ETFE cushion has an individual air pipe attached to a central air handling unit. As the cushions only need to maintain pressure and not generate air flow, the energy consumption used by these units is minimal.  An entire roof is generally powered by a single air handling unit which contains 2 fans powered by electric motors.

The fans run alternately to maintain pressure within the cushions, with only one fan running at any given time. In the event of a cushion failure, adverse weather conditions or a drop in cushion pressure, both fans will run simultaneously to maintain a steady pressure. If required, the inflation units are also fitted with dehumidifiers to dry the air being fed into the cushions.

A typical air inflation unit measures 1.2m x 1.2m x 0.9m and is located near to the ETFE cushion system, either up on the roof or in a plant room. The system requires a dedicated and secure power supply consisting of two 240V 13 amp electrical connections as the ETFE foil roof is a live system the cushions are permanently linked to the air inflation unit to ensure the pressure is maintained.

Questions? Call our technical team on 01291 638200 for more information on ETFE systems and how one could work for you.

Want to see our earlier blog posts in the ETFE series? Click here