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: 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: An enclosure surrounding the burner of a furnace, including a top panel, a rear panel, a bottom panel, a front panel, and first and second side panels. An air inlet is provided in one of the panels. A baffle is provided within the enclosure and extends between two opposed panels, each of the opposed panels adjacent the panel having the inlet. A chamber is partly defined by the baffle, the inlet opening into the chamber. The chamber is provided with a vent through which the inlet is in fluid communication with the burner.

Abstract: A heat exchanger (10) including a heat exchanger conduit and fins arranged on the conduit tubes (12, 12') to further heat transfer between the external fluid flowing over the fins (22, 22') and the fluid flowing within the conduit. The fins (22, 22') include a row of apertures through which tubes (12, 12') of the heat exchanger conduit extend. The leading (4, 6) and trailing (48) edges of the fins (22, 22') are contoured to substantially conform to isotherms around the circulating fluid flowing within the tubes (12, 12'). To achieve this edge configuration while also allowing for a dense packing of fins and tubes in a multi-row heat exchanger, the leading and trailing edges are wave-shaped such that adjacent fins can interfit together.

Abstract: The present invention is a charge balance device for a heat pump. The heat pump system has a heating and a cooling mode and includes an indoor heat exchanger, an outdoor heat exchanger, a compressor, refrigerant circuitry connecting the heat exchangers and the compressor in series arrangement, with the charge balance device connected in parallel arrangement with the outdoor heat exchanger. An accumulator is connected in line with the refrigerant circuit at a point immediately upstream of the suction side of the compressor for storing excess liquid refrigerant during heating mode. The charge balance device includes a check valve for blocking refrigerant flow, thus preventing the diversion of refrigerant flow around the outdoor heat exchanger during cooling mode, and a restrictor orifice for throttling refrigerant flow, thus regulating the flow of refrigerant diverted around the outdoor heat exchanger during heating mode.

Abstract: The present invention involves a rain shield assembly for a package air conditioner and heat pump unit. A cover is pivotally mounted to the package unit housing and has a sealing pad made of a resilient foam material. When the cover is moved to a sealing position, the foam pad contacts foam sealing strips that are attached to the unit housing and that separately ring access openings provided in the housing. Electrical circuitry such as circuit breakers may port through these access openings. Cavities are provided in the sealing pad in alignment with the access openings to accommodate projecting handles or switches of the electrical circuitry. The contact between the sealing pad and the sealing strips forms water-tight seals around the portion of the electrical circuitry projecting from the package unit housing so as to protect the circuitry from potentially damaging exposure to the elements.

Abstract: The present invention is an enhanced tubular heat exchanger for a furnace with the heat tubes of the heat exchanger having two straight sections connected by a bend. The tubes of the heat exchanger include an enhanced portion which has a smaller cross-sectional area than the flue portion, in the form of an elliptically shaped tube. The enhanced portion further includes turbulators to promote the heat exchange from the heated flue gases. Circulation of air around the exterior of the tubes is also facilitated because the enhanced portion is disposed at a small angle relative to the flue portion. A plurality of tubes are disposed within the heat exchanger so that the circulation air first flows over the enhanced portions then over and around the generally cylindrical portions. This lowers the initial pressure drop in the circulation air flow and thereby facilitates the circulation of and heat transfer to the air being heated.

Abstract: An induced draft, fuel-fired furnace having a heat exchanger with an inlet and an outlet includes a vent having an inlet, a burner, and a vented vestibule in fluid communication with the vent. A blower has an inlet in fluid communication with the heat exchanger outlet, and an outlet disposed at the inlet of the vent. The blower outlet has a cross-sectional area smaller than the vent inlet. The vent inlet and blower outlet define a vent inlet opening. A drafthood formed with an inlet is disposed in the vestibule and forms a plenum in fluid communication with the vent inlet opening. A source of combustion products is disposed in the furnace such that combustion products produced thereby are in fluid communication with the drafthood inlet and vent inlet opening. The source of combustion products includes either a standing pilot or electronic ignitor for igniting fuel operably discharged from the burner.