Ventilation system heat recovery equipment - has heat exchanger deicer operating automatically at low inlet air temp.

摘要

The heat recovery equipment is for a ventilation system with forced feed and discharge of air, having a unit (15) giving indirect heat exchange between the inlet and outlet air, and a further unit (25) automatically keeping the first one free of ice. Third and fourth units (31, 33) are provided, operating dependent on the incoming air temp. from the heat exchanger, and causing the second unit to operate whenever this temp. falls below a first value. They can be formed by a thermostat switch, whose temp. sensor (31) has the incoming air from the heat exchanger flowing round it. The sensor is part of a circuit controlling an electric preheater, upstream of the heat exchanger.