Unit ventilator

Claim 1

IN A ROOM UNIT VENTILATOR INCLUDING A CABINET HAVING A ROOM AIR INLET AND AN OUTDOOR AIR INLT, AN AIR OUTLET, AND BLOWER MEANS FOR INDUCING THE FLOW OF AIR THROUGH SAID CABINET: (A) PRIMARY DAMPER MEANS MOVABLE IN A RANGE BETWEEN ONE EXTREME POSITION BLOCKING SAID ROOM AIR INLET AND AN OPPOSITE EXTREME POSITION BLOCKING SAID OUTDOOR AIR INLET; (B) MEANS FORMING A SEPARATE COOLING PASSAGE AND A SEPARATE HEATING PASSAGE BETWEEN SAID AIR INLETS AND SAID AIR OUTLET, EACH PASSAGE HAVING A HEAT EXCHANGER THEREIN ADAPTED TO SELECTIVELY RECEIVE A TEMPERING MEDIUM OF THE CHARACTER OF THE PASSAGE WITH SAID HEAT EXCHANGERS AT TIMES SIMULTANEOUSLY RECEIVING THEIR RESPECTIVE TEMPERING MEDIUMS; (C) SECONDARY DAMPER MEANS AT THE INLET END OF SAID PASSAGES MOVABLE IN A RANGE BETWEEN ONE EXTREME POSITION BLOCKING SAID COOLING PASSAGE AND AN OPPOSITE EXTREME POSITION BLOCKING SAID HEATING PASSAGE; (D) MEANS OPERATING SAID PRIMARY DAMPER MEANS THROUGHOUT SAID RANGE IN ACCORDANCE WITH DEPARTURES IN ROOM TEMPERATURE FROM A DESIRED TEMPERATUR WHEN SAID HEATING PASSAGE HEAT EXCHANGER IS RECEIVING A TEMPERING MEDIUM, AND RESTRICTING OPERATION OF SAID PRIMARY DAMPER MEANS TO A PART OF SAID RANGE LIMITING ADMISSION OF OUTDOOR AIR WHEN ONLY SAID COOLING PASSAGE HEAT EXCHANGER IS RECEIVING A TEMPERING MEDIUM; (E) AND MEANS OPERATING SAID SECONDARY DAMPER MEANS TOWARD SAID ONE AND SAID OPPOSITE EXTREME POSITION TO VARY IN PROPORTIONING FASHION THE AIR DIRECTED THROUGH SAID SEPARATE PASSAGES IN RESPONSE TO DEPARTURES OF SAID ROOM TEMPERATURE RESPECTIVELY BELOW AND ABOVE SAID DESIRED TEMPERATURE, IRRESPECTIVE OF WHETHER BOTH OR ONLY ONE OF SAID HEAT EXCHANGERS IS RECEIVING A TEMPERING MEDIUM.