Room ventilation unit with exhaust air heat recovery - uses heat exchanger between incoming and outgoing air ducts to recover energy and has supplementary heating in duct

摘要

The room ventilation unit has an enclosure with four openings, two into the room and two to the exterior. Two independent air circuits, each connecting one external opening and one internal opening, are used, one to extract air from the room, the other to bring in air from outside. A heat exchanger is fitted between the two air passages, extracting heat from the exhaust air to warm or cool the incoming air, as is appropriate to the prevailing interior and exterior conditions. An electric resistance (15) is used to heat incoming air, under control of a thermostat (16), when the internal air is warm. The air intake circuit has the fan operation controlled by the pressure in the exhaust passage, using a pivoted vane (17) carrying a mercury switch.