Abstract: An incipient failure indication apparatus for an environmental control system which includes a heat exchanger through which air flows and a temperature control thermostat. The indication apparatus includes an indicator having an alarm in communication with a control board, the control board in communication with the thermostat. The alarm has a visual indicator and/or an aural indicator, whereby the attention of a person is attracted to the indicator upon activation of the alarm. A first temperature sensor is disposed on the upstream side of the heat exchanger and a second temperature sensor is disposed on the downstream side of the heat exchanger, whereby the temperature sensors respectively sense the temperature of the air upstream and downstream of the heat exchanger. The first and second temperature sensors are in communication with the control board, and the control board has means for comparing the temperatures sensed thereby.

Abstract: The present invention involves package air conditioner and heat pump units. The unit has a housing containing a compressor, an outdoor section with blower and heat exchanger, and an indoor section with blower and heat exchanger. The indoor section has two interchangeable removable panels, one removable panel defining a supply port and a second removable panel defining a return port. The return and supply ports of the housing are reversible because of the unique blower assembly which has a blower attached to the second panel. The blower assembly is adapted to be disposed in at least two positions in said housing. With this arrangement, the return port and the supply port are reversible by switching the position of the first panel and the blower assembly.