Abstract: Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, methods of managing refrigerant charge, and methods for heating and cooling a space and for heating water. Various embodiments deliver refrigerant gas to a heat exchanger that is not needed for transferring heat, drive liquid refrigerant out of that heat exchanger, isolate that heat exchanger against additional refrigerant flowing into it, and operate the heat pump while the heat exchanger is isolated. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled or adjusted by controlling how much liquid refrigerant is driven from the heat exchanger, by letting refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and segments of refrigerant conduit can be interconnected with various components.

Abstract: Heat pumps for climates where demand for cooling and heating are unequal and methods of adapting and distributing heat pumps for such climates. Heat pumps include a compressor, compressor motor, variable-speed drive, and controller. In a number of embodiments, non-volatile memory stores sets of constant speeds for cooling and heating, and a person can select, via an input device, different sets of speeds for cooling and heating to provide the different cooling and heating capacities. The controller then operates the unit at the selected speeds, selecting from within the set based on demand for cooling or heating. In some embodiments, different sets of speeds may have the same minimum speed but different maximum speeds. Identical heat pumps can be configured to have different capacity ratings and different advertized efficiencies for different climates.

Abstract: Air conditioning units packaged with condensing gas heat exchangers include a drain line connected to a collector attached to the heat exchanger. In different embodiments, the drain line, or a conduit for the drain line, may extend to the return duct opening for routing of the drain line through the return duct for disposal of the condensate, for instance, within the building, or the drain line may extend through a hole in the floor of the unit. The conduit may protect the drain line from direct heat from the heat exchanger, from freezing where the drain line passes through an outdoor section, or both. In some embodiments, air may be circulated through the conduit to prevent freezing. The conduit may guide the drain line through the unit, roof curb assembly, or roof, or the drain line may be routed through the unit by the manufacturer to the return duct opening.

Abstract: Air conditioning units packaged with condensing gas heat exchangers where condensate from the heat exchanger passes through the inducer fan, into an exhaust conduit, and out of the unit enclosure, and methods that reduce consumption of fossil fuels using air conditioning units with condensing gas heat exchangers by advertising that the units can be installed on the roof of a building or at ground level. Some embodiments include a drain hole extending through a collector attached to the heat exchanger to the inlet of the inducer fan. In some embodiments, a bifurcation in the exhaust conduit separates condensate from most combustion gasses. Some embodiments discharge condensate into a vertical standpipe in the ground that may extend below the frost line. Various methods include instructing an installer of the units regarding how to install the units and dispose of condensate into the ground or through a drain line into the building.

Abstract: Air conditioning units packaged with condensing heat exchangers, collectors for such units, and apparatuses for passing a tube through a duct wall and making a loop and trap in the tube. In different embodiments, a drain line may connect to a collector attached to the heat exchanger or condensate may discharge through an inducer fan and out with combustion gasses. A drain line opening in the collector may be lower than a drain hole to the inlet of the inducer fan, which may be lower than an exhaust hole for the fan. A plug in the drain line opening in the collector may be used to discharge condensate through the inducer fan and a bifurcation in the exhaust conduit may separate condensate from most combustion gasses. Embodiments having a drain line connected to the collector may route the drain line through the roof, a conduit, or in the return duct.

Abstract: Methods of controlling air conditioning and HVAC units using a thermostat for a discrete-speed unit that include changing speed based on how long the unit operates at a particular speed. Speed may be increased if a unit operates for longer than a predetermined time at a particular speed, and speed may be reduced if the unit operated for less than a specific amount of time during the prior run. In different embodiments, single-stage thermostats may control units that operate at three speeds, and two-stage thermostats may control units that operate at three to five or more speeds. In addition, in some embodiments, outdoor coil temperature may be measured and considered in determining speed. Further, in some embodiments, maintaining continuous or repeated operation at a boost speed may be avoided. Energy savings and noise reduction may result.

Abstract: Premix furnace for heating an occupied space while producing lower NOx emissions and methods of mixing air and fuel delivered to a premix burner and of improving combustion stability. A mixing device may be located within an inlet tube, may have a flat surface that is perpendicular to the direction of fuel flow, or may have two surfaces held at substantially opposite angles to induce swirl. A mixing device may be attached to the fuel injector, may be made from a piece of sheet metal, and may have bends and a hole for attachment to the fuel injector. A fluidic diode in the inlet tube may improve combustion stability and may include a hollow frustum or a frustoconical portion, a cylinder concentric with the inlet tube, or a combination thereof. Some embodiments include refractory insulation lining the combustion chamber or may adjust for elevation or fuel characteristics.

Abstract: A control procedure operates an expansion valve of an air conditioning system. The control procedure utilizes a first control procedure to bring a calculated superheat value within a range of a target superheat value, and a second control procedure to cause the calculated superheat value to match the target superheat value. Both the first and second control procedures preferably use Proportional, Integral, Derivative control algorithms.

Abstract: Relatively constant temperatures are maintained in a space by varying the capacity of heating or cooling equipment. A proportional band is used to adjust capacity to compensate for changes in heating or cooling load, and the proportional band is adjusted to bring the actual temperature within the space closer to the set point temperature. Such an adjustment may be made by determining the difference between the present temperature and the set point temperature, and adjusting a floating temperature set point by a percentage (e.g., ten percent) of the difference. Such a process may be repeated, for example, at regular intervals, such as once per minute. As a result, the temperature within the space approaches (e.g., asymptotically) the set point temperature whether the heating or cooling load is high or low. Methods, systems, and apparatuses are contemplated, including HVAC units and controls, including for residential applications, including using variable-speed drives.

Abstract: NOx reduction apparatuses for use in heat exchangers or furnaces, HVAC units and buildings having such devices, and methods of making such devices. Wire embodiments may have a body, helix, or modified helix, and support members that extend outside the body to hold the body away from the heat exchanger or tube. The support members may be made of the wire, and may include bights, twisted bights, or larger (e.g., helical) turns, for instance, between groups of smaller helical turns. In some embodiments, a modified helix is formed by alternating bends and straight sections of wire. Some embodiments include an attachment mechanism that may be made from the wire and may include a hook. Wire may be Nichrome. Particular embodiments may allow burning of natural gas or LP without changing or removing the wire.

Abstract: Compact and efficient apparatuses for transferring heat, heat exchangers, and furnaces, as well as HVAC units, HVAC systems, and buildings therewith, plus methods of making such devices. Furnace heat exchangers, for example, have an added stage, added in an unconventional way, that improves efficiency without unduly increasing size, while maintaining required radiuses of bends in tubing. Various embodiments orient bends at particular angles to allow stages to fit together more closely, provide improved structure for connecting stages using two collectors that seal against a common junction plate, provide for indoor air passing through the heat exchanger to pass through different passes of the heat exchanger in an unconventional order in order to provide greater compactness, or a combination thereof, as examples.

Abstract: HVAC units and systems, air conditioning units, and heat pumps that have micro-channel heat exchangers wherein fins are slanted, multi-tubes are oriented non-horizontally (e.g., vertically), or both, for example. Fins may be slanted downward in the direction of air flow to facilitate drainage of condensation, or may be slanted either downward or upward as appropriate to reduce air-flow restriction. Other embodiments include the heat exchangers themselves and buildings having such heat exchangers, units, or systems, as well as methods concerning such devices, such as methods of manufacture. In some embodiments, heat exchangers are used as evaporators in air conditioning units, as condensers in heat pumps, or both, as examples.

Abstract: Tubing having internal fins projecting inward from the tube wall, each fin having an external surface that includes multiple acute interior angles or crevices that may form nucleation boiling sites, heat exchangers comprising such tubing, and methods of making same. Acute angles, crevices, or elongated slits may be formed in the sides, center, or both, of the fins or between the fins and the tube wall, and convex rounded surfaces may be provided therebetween. Fins may be parallel to the tube centerline or helically wound. Tubing may be expanded with a bullet which may form an interference fit with external fins, may modify the fins to create more effective nucleate boiling cavities, or both.

Abstract: Air conditioning units, methods of manufacturing, inventories, and buildings wherein certain heat exchanger modules are combined to make air conditioning units. In some embodiments, different combinations of different size modules are used to produce air conditioning units having different capacities wherein some identical modules are used in different size units. Various heat exchanger assemblies include spacers between modules, bends formed after modules are assembled into heat exchanger assemblies, attachment rails at the ends of the modules, inactive multi-tubes at the top and bottom of the modules, copper tubing between aluminum modules to facilitate field replacement of individual modules, name plates that attach between modules, attachment clips or spacers that snap attach to the modules, or a combination thereof, as examples.

Abstract: A control procedure operates an expansion valve of an air conditioning system. The control procedure utilizes a first control procedure to bring a calculated superheat value within a range of a target superheat value, and a second control procedure to cause the calculated superheat value to match the target superheat value. Both the first and second control procedures preferably use Proportional, Integral, Derivative control algorithms.

Abstract: Airflow rates within a ventilation system are controlled using motor speed or torque and motor electric current or pressure. Fan speed or torque may be varied to compensate for differing restriction in ductwork, and may provide a constant airflow rate over a range of varying airflow restriction. Air handlers or air conditioning units may be mass produced in common configurations, and installed in different buildings or structures with different ductwork configurations. Methods operate a fan motor at a present speed or torque, sample speed or torque, sample current of the fan motor or pressure within the ventilation system, calculate a present airflow rate within the ventilation system, calculate a new input setting using the present airflow rate and a target airflow rate, change the speed or torque to the new input setting, and repeat these steps to converge on the target airflow rate, often avoiding overshoot.

Abstract: A blowerless air conditioning or heat pump system for use in providing conditioned air includes an outdoor section that is preferably coupled to an indoor section, and is advantageously used with a forced hot air furnace and a corresponding air distribution duct system of a home or building. The two sections are preferably installed along a boundary of the home or building such that outdoor section is outside of the home and the indoor section is inside or below the home and proximate to a forced hot air furnace. Disposed within the outdoor unit are a compressor, an outdoor coil and an outdoor fan. Disposed within the indoor section is an evaporator coil. There is no separate fan or blower disposed within the indoor section. An inlet air tube couples the indoor section to a first point in the air distribution system, and an outlet air tube couples the indoor section to a second point in the air distribution system. The second point is downstream of the first point relative to the furnace.

Abstract: An improved high-efficiency furnace for use with manufactured housing has a modular heat exchanger assembly having a drum and a plurality of serpentine shaped tubes. A burner extends at least partially into the drum portion of the heat exchanger which acts as a combustion chamber. Hot combustion gases flow upwardly within the drum and enter the tubes heating the drum and tubes. Room air is drawn into the furnace by a circulating blower and blown against the plurality of tubes. The room air is then directed to flow around the drum portion of the heat exchanger where it is further heated before being discharged into the space being heated. The burner includes an inwardly tilted target plate having a plurality of fingers for facilitating the formation of a stable ball of flame within the drum.

Abstract: A heat pump unit for use in small buildings where the unit must be stored in a confined space, not having access to the exterior walls of the building. The unit is contained within a rectangular housing that is divided into three compartments. An outdoor air compartment is vertically disposed between the top and bottom walls at the rear of the housing and an indoor air compartment and a compressor compartment are mounted one over the other at the front of the housing. An outdoor air blower is mounted outside of the housing to save space and is arranged to move air through the outdoor air compartment along a vertical path of travel. An interior vertical wall separates the rear compartment from the two front compartments and contains an upper vertical section and rear wall offset lower vertical section joined by an angularly disposed intermediate section along a vertical path of travel.

Abstract: A single package heat pump unit is field-reconfigurable from a horizontal discharge configuration to a top discharge configuration. A supply panel covers the top and upper part of the back wall, and contains a supply vent in a vent wall, with a blank wall joining it at a ninety degree crease. The supply panel can be removed and installed in the top discharge position, using standard fasteners.