Abstract: An HVAC system with a refrigerant gas sensor is provided. In one embodiment, an HVAC system includes a heat exchanger coil installed within a housing. The heat exchanger coil is operable to exchange heat with air in the housing via a refrigerant passing through the heat exchanger coil. The system also includes an HVAC sensor assembly installed within the housing. The HVAC sensor assembly includes a refrigerant gas sensor and an orientation sensor positioned to detect an orientation of the refrigerant gas sensor. The HVAC system may also or instead include a position sensor to detect the position of the refrigerant gas sensor within the system. Additional systems, devices, and methods are also disclosed.

Abstract: An HVAC system is provided. Embodiments of the present disclosure generally relate to heat exchangers having tubing with a reduced diameter compared to traditional systems. In one embodiment, a ducted HVAC system comprises an outdoor heat exchanger with tubing that has an outer diameter of eight millimeters (8 mm) or less and an indoor heat exchanger with tubing that has an outer diameter of nine millimeters (9 mm) or less. Additional systems, devices, and methods are also disclosed.

Abstract: A reversible heat pump system with one bi-flow expansion device. A four-way valve in the refrigerant circuit may be configured in either a cooling mode or a heating mode. In the cooling mode, a compressor is operable to flow a refrigerant out a compressor outlet and through the bi-flow expansion device in a first direction. In the heating mode, the compressor is operable to flow the refrigerant out the compressor outlet and through the bi-flow expansion device in a second direction, opposite the first direction. Thus, only one thermal expansion device is needed for a reversible heat pump heating, ventilation, and air conditioning (HVAC) system without the need for bypass lines and check valves around the bi-flow expansion device. Further, if an accumulator is included before the compressor, the bi-flow expansion device may be controlled to store at least some refrigerant in the accumulator, thus allowing the evaporator superheat to be lower than if the accumulator were not used.

Abstract: A heating, ventilation, and air conditioning (HVAC) system includes one or more compressors, one or more outdoor heat exchangers, and one or more indoor heat exchangers. The HVAC system also includes a base pan on which the one or more compressors are mounted. The base pan includes a base level and one or more tier levels higher than the base level. The distance from any point on a perimeter of the first-tier level to a nearest point on a perimeter of the base level is based on the smallest bolt circle diameter of the one or more compressors mounted on the base pan. Also, the perimeter lengths of the tier levels are based on a percentage of the base level perimeter length.

Abstract: A system and method for controlling the air temperature of a building using a control plan based on a target time. The system includes a controller which may be connected to a number of indoor and outdoor heating ventilation and air-conditioning units. The system may include a thermostat. The system may also operate without a thermostat. The method includes determining a control plan to reach a desired temperature in a target time. The method also includes updating the plan by comparing the actual time to reach the desired temperature with the target time.

Abstract: A tubular burner and methods of use in a furnace having reduced NOx emissions are provided. The tubular burner comprises a structural skeleton and a mesh screen disposed about the structural skeleton. The structural skeleton may be coupled to an air/fuel mixture source. The structural skeleton may comprise a hollow interior and a plurality of perforations to allow the air/fuel mixture to pass from the interior of the structural skeleton to the exterior. The burner systems may further comprise a plurality of holes spaced along and between the burners for cross-lighting of multiple burners using a single igniter.

Abstract: A system and method for controlling the air temperature of a building using a control plan based on a target time. The system includes a controller which may be connected to a number of indoor and outdoor heating ventilation and air-conditioning units. The system may include a thermostat. The system may also operate without a thermostat. The method includes determining a control plan to reach a desired temperature in a target time. The method also includes updating the plan by comparing the actual time to reach the desired temperature with the target time.

Abstract: A drain pan and a method for fabricating a drain pan for use with an air conditioner, the drain pan having a plastic drain having plastic threads, with an insert disposed within the plastic drain to prevent the fracturing of the plastic threads when a steel pipe is threaded into the plastic drain. The insert may be a metal insert.

Abstract: A clasp for an ornamental object comprising a base, a top, and a link. The link engages the base. The engagement occurs where at least one projection and an aperture from the link respectively engage at least one cavity and a post from the base. The engagement between the base and top is further secured by moving the top and the base proximal each other such that the link is positioned between the two. Magnetic force is used to position the top and base proximal each other.

Abstract: A warm air furnace and method for securing a thermostat to a wall of a warm air furnace utilizes a thermostat mounting flange which has its ends forced inwardly into openings formed in a wall of the furnace, and the thermostat may be secured to the wall of the furnace without the use of screws.

Abstract: A warm air furnace and method for securing a thermostat to a wall of a warm air furnace utilizes a thermostat mounting flange which has its ends forced inwardly into openings formed in a wall of the furnace, and the thermostat may be secured to the wall of the furnace without the use of screws.

Abstract: An upflow/downflow high efficiency furnace includes a means for mounting a secondary heat exchanger by use of a hinge member, which permits the furnace to be installed in either an upflow or downflow mode of operation, without any modification to the furnace as manufactured.

Abstract: A pilot pressure switch for a furnace detects the fluid pressure within the pilot line for a pilot flame, and upon the fluid pressure in the pilot line exceeding a predetermined value, an electrical signal from a thermostat may be passed to a furnace blower control to operate the furnace main blower and furnace vent blower.