Air Admittance Valves

• Designed to reduce the number of ventilating pipes which pass through the roof
• Valves can be installed in a ventilated duct or the roof space
• Conventional ventilation is required if more than 5 dwellings are equipped with a valve
• The valve must not be at risk of freezing and therefore should not be fitted externally. It should also be accessible for inspection and testing.
• Must be fitted above the flood level of the highest appliance.