An innovative cowl designed to counteract the adverse effects of external wind on the performance of mechanical extract ventilation systems and passive vents has been launched by Airtech Environmental Systems. Called the Energysaver Cowl the patented product is up to 20% less resistant to airflow and has the capability to make any extractor fan up to 20% more energy efficient. The cowl also alleviates ‘blow back’ thus further increasing extractor fan efficiency and reducing energy consumption – all of which contribute to a reduction in the carbon footprint.

Conventional grilles, even those with gravity flaps, are adversely effected by upward and cross winds that significantly reduce their Effective Area. This has serious adverse implications, particularly in relation to energy consumption and the statutory fresh air requirement for gas vents and energy consumption.

The standard test to determine Effective Area is measured in outside ‘still air’ conditions and wind effect can reduce this by up to 50%. Wind speeds as low as 5m/sec will make it impossible for most domestic mechanical ventilators to achieve 15litres/sec extraction.

The Energysaver Cowl is especially suited to installations in windy locations and high rise buildings and is suitable for window and wall fitting, passive vents and mechanical extract installations.