Abstract: A heating system with a hot water coil is provided with a variable speed blower whose speed is regulated in response to a sensed load in the system. Heat can therefore be added to the hot water by way of a simple burner system, with the required control being effected by selectively varying the amount of heat that is removed from the hot water by controlling the fan speed. When applied to a zone controlled system, the need for a bypass duct is obviated.

Abstract: Support for the heat exchanger tubes of a gas-fired, year round air conditioning unit are provided by a pair of interlocking, wire frame elements that sandwich the tubes therebetween and are, in turn, securely attached to the frame structure. The two elements are biasingly interlocked in a safety pin fashion, with the combination providing adequate support while, at the same time, offering little resistance to the flow of air over the supported tubes.

Abstract: The indoor blower scroll structure includes integrally formed vent and exhaust port walls with associated doors attached thereto. A single actuator mechanism is also attached to the scroll structure and is mechanically linked to both doors to thereby provide a single and reliable actuation assembly, all of which is mounted on the scroll structure. In a preferred embodiment, the actuator comprises a single, lever actuated cam which directly engages levers on both the vent and exhaust doors.

Abstract: A silencer device is installed into the discharge pipe of a centrifugal compressor by first installing a channel shaped frame in the discharge pipe and then sliding the silencer device into the frame to be contained for operational use. The orientation and placement of the frame and its contained silencer device is parallel with the direction of flow to thereby reduce the resulting pressure drop, and it is placed near a turn in the discharge pipe such that the sound will tend to be reflected from the discharge pipe to cause multiple passes through the silencer device and thereby enhance its absorptive performance. The absorptive material within the silencer device is protected from erosion by a surrounding cloth bag composed of a fine weave Nomex material.

Abstract: A header for a tube-in-tube heat exchanger is formed in a single piece such that the manifold plate in one end thereof is integrally formed with the header body. Such a design eliminates the process of brazing the manifold plate into the header body, thus substantially simplifying the assembly process. In order to accommodate thinner walled tubes and a thinner manifold plate, reinforcing sleeves are placed around the inner tubes ends and are brazed in place in the manifold plate openings.

Abstract: A labyrinth seal is provided to isolate the transmission from a balance piston of a centrifugal compressor, the labyrinth seal being pressurized with refrigerant vapor from the motor chamber, which vapor is at a pressure slightly above that in the transmission, to thereby minimize the efficiency losses that would otherwise occur from leakage of the vapor into the transmission and to the compressor suction.

Abstract: In order to enhance the efficiency of removing refrigerant from the mixture of non-condensable gases in a purge recovery system, a carbon filter is placed in the flow of mixed gases from the purge chamber such that any remaining refrigerant can be absorbed by the filter and not be vented to the atmosphere with the non-condensable gases. The filter is periodically reactivated by the operation of a vacuum pump to remove the refrigerant from the carbon filter and return it to the system refrigeration circuit. The reactivation process is initiated and controlled by way of a pressure switch and a timer.

Abstract: Provision is made for stacking one condenser on another by mounting apparatus which includes a channel for receiving and supporting the existing feet at the base of the upper unit, and a clip member for securing the combination to the lower edge of the lower unit cover. Where the upper and lower units are the same size, a single fastener attaches both the feet and the clip to the channel. Where the upper unit is smaller than the lower unit, separate fasteners are applied to secure the feet to the channel and to secure the channel to the clip.

Abstract: In a gas furnace designed for operation with natural gas, the use of propane as a fuel is facilitated by increasing the inducer speed by a factor which is obtained by comparing the higher inducer speed necessary to bring down the heat exchanger temperature to an acceptable level, with the original lower inducer speed that had caused the temperature to exceed the allowed limit. Provision is made for electronically applying the multiplying factor by simply operating a gas selector switch.

Abstract: A blower motor failure is detected by a sensor/switch that opens at a first preset temperature level and automatically resets for the next cycle. The occurrences of such openings per thermostat cycle are counted and when they reach a predetermined number, the microprocessor causes the system to lockout from further operation, thereby preventing the temperatures from reaching excessive levels. In order that the same system may be used in a horizontal furnace installation where the first sensor is less responsive because of its location, a second sensor, of the manually resettable type and having a preset temperature level for opening which is higher than said first temperature limit, is employed to thereby lockout the system.

Abstract: A furnace which normally operates from a residential AC power source is adapted to operate on auxiliary DC power by changing the normal control function to substantially prevent the furnace from operating in the high heat mode during periods of auxiliary power use. Relays can be used to automatically connect the emergency power and to effect the change of the control function.

Abstract: A wire raceway member, for containing the wires which extend between a fan motor and its separate control module, is formed of a lower U-shaped portion and an upper expandable portion. An opening in the expandable portion is normally smaller than the diameter of the wires to be contained but, when temporarily expanded, the width is wider than the diameter of the wires so as to enable the insertion of the wires into the slot. The ends of the raceway have integrally formed members that are attachable to the motor and to the orifice ring, respectively, without fasteners. A radially extending portion of the grille cover is aligned with the top slot of the raceway member so as to thereby act as a cover to prevent the inflow of moisture into the raceway member.

Abstract: In a centrifugal compressor having an ejector for reclaiming the oil which tends to accumulate in a lower portion of the suction housing, the ejector high pressure line is provided with its inlet at the bottom of the collector such that, in addition to providing the high pressure power to the ejector, it also functions to pump out any oil that has accumulated at the bottom of the collector and to discharge it into the oil sump.

Abstract: In an air conditioning system having the outdoor coil disposed in a wall opening with the outdoor air being required to flow horizontally inwardly pass through the coil and then flow horizontally outwardly as it is discharged, the propeller fan is placed in a horizontal plane at the top end of the coil such that the air is caused to flow into an upper plenum where the air is turned 90 degrees to be discharged. The height of the plenum is preferably chosen to optimize the performance while minimizing the plenum height.

Abstract: A heat pump system communicating water from a remote source for heat exchange with a localized refrigerant loop including compressor and evaporator elements, said refrigerant loop further linked to a blower for additional heat exchange with respect to selected rooms and spaces which are desirably selectively heated or cooled, said compressor, evaporator and blower and additional elements packaged as a single local unit and adapted to communicate with said external water source for acquistion or disposal of heat.

Abstract: An outdoor heat exchanger coil has a fan on one side thereof for forcing ambient air through the coil and a partition on the other side thereof. The partition is placed relatively close to the coil to thereby define a channel which allows the flow of ambient air therethrough without any substantial decrease in system capacity or airflow. A comparison between the channel width and the channel length is made to define the limits of minimal separation between the coil and the partition.

Abstract: The elbow between the discharge end of the draft inducer and a horizontal vent pipe is provided with a well structure on the lower side of its discharge end such that condensate forming in the vent pipe is prevented from passing through the elbow into the draft inducer housing. The well structure, in addition to restraining the flow of the condensate, provides for the draining off thereof, and presents a minimal restriction to the flow of flue gases flowing to the elbow. Provision is also made for maintaining a tight seal between a rectangularly shaped inlet lip of the elbow and a rectangularly shaped discharge end of the inducer housing by making the inlet lip of varying thicknesses, with the lip being thinnest at its corners and thickest at its side midpoints.

Abstract: A gas fired condensing furnace comprising a multiple cell condensing heat exchanger is provided wherein each condensing heat exchanger cell has a condensing flow passage of serpentine shape formed from a single flat sheet metal blank. The condensing heat exchanger cell is formed to be compact in size and to minimize heating fluid side pressure drop therethrough. The condensing flow passage for each condensing heat exchanger cell provides high velocity fluid flow therethrough for increasing its heat transfer characteristics.