A furnace including a combustion chamber for burning fuel can have increased fuel burning efficiency, increased heating efficiency, and decreased harmful emissions of combustion byproducts. A combustion air delivery system delivers primary and secondary combustion air to the combustion chamber. Primary and secondary combustion air may be delivered at amounts that increase burning efficiency. An amount of secondary combustion air can be controlled by a valve system. A heat transfer device efficiently transfers heat from products of combustion for heating an enclosed space.

A solar thermal control system includes a membrane configured to receive solar energy, wherein the membrane is configured to form a cavity between the membrane and an outer surface of a structure by coupling to the outer surface, and wherein the solar energy is configured to heat air within the cavity. The control system also includes a thermal collection unit configured to connect to the cavity and receive and direct air from the cavity, and a ducting system coupled to the thermal collection unit and configured to direct air from the thermal collection unit to at least one of the interior of the structure and a vent.

An energy storage-combined cooling, heating and power (S-CCHP) system for a building receives energy from a source, for example an intermittent source, and stores the energy in first and second high temperature energy storage (HTES) units. A Brayton cycle using the first HTES unit produces hot and pressurized air that is further heated in the second HTES unit. The heated air drives a turbine to generate electricity for the building. A portion of the compressed air from the Brayton cycle is diverted to a hot water heat exchanger, then to another turbine to produce electricity to the building. The hot water heat exchanger heats water for the building and the other turbine exhaust cools water for building cooling. Heat exchangers are strategically placed to optimize the thermal efficiency of the cycle. In some embodiments the heat transfer fluid is humidified to improve thermal energy transfer properties.

A solar phase-change energy storage heating ventilation partition wall and modular heating system thereof, the partition wall consists of a solid partition wall (1), a thermal insulation layer (2), a decoration layer (3), frame of steel reinforcement (4), reflecting layers (5) and phase-change heat storage modules (6), the modular heating system comprises a solar air collector (13), phase-change heat storage units (23) arranged modularly, and a partition wall, to achieve energy storage and heating. Compared with the prior art, the modular heat storage partition wall components are simple in manufacturing process and flexible in assembly, and can be freely arranged and combined according to actual conditions; the system collects solar energy by the solar air collector during the daytime and stores the heat in the phase-change heat storage modules in the partition wall; and the heat storage partition wall can provide heat for the room in a radiation manner.

A furnace including a combustion chamber for burning fuel can have increased fuel burning efficiency, increased heating efficiency, and decreased harmful emissions of combustion byproducts. A combustion air delivery system delivers primary and secondary combustion air to the combustion chamber. Primary and secondary combustion air may be delivered at amounts that increase burning efficiency. An amount of secondary combustion air can be controlled by a valve system. A heat transfer device efficiently transfers heat from products of combustion for heating an enclosed space.

A furnace including a combustion chamber for burning fuel can have increased fuel burning efficiency, increased heating efficiency, and decreased harmful emissions of combustion byproducts. A combustion air delivery system delivers primary and secondary combustion air to the combustion chamber. Primary and secondary combustion air may be delivered at amounts that increase burning efficiency. An amount of secondary combustion air can be controlled by a valve system. A heat transfer device efficiently transfers heat from products of combustion for heating an enclosed space.

A furnace controller for a modulating furnace that helps provide a balance between energy efficiency and occupant comfort across various burner firing rates and/or across various circulating blower speeds. In some cases, the furnace controller can be configured to permit a user to customize operation of the furnace in accordance with their particular needs and/or desires with respect to efficiency and comfort. A selection may be made between an energy efficiency setting and a user comfort setting. Then, a plenum parameter such as a discharge air temperature (DAT) or discharge air flow (DAF) may be regulated in accordance with the selected setting.

A furnace inducer choke and a gas furnace employing the furnace inducer choke. In one embodiment, the furnace inducer choke includes: (1) a choke body configured to engage a furnace inducer blower, the choke body having an opening extending entirely therethrough to limit an amount of combustion air entering a furnace that the furnace inducer blower is attached, and (2) a tab protruding from the choke body a distance sufficient to identify the opening when the choke body and furnace inducer blower are installed in the furnace.

A furnace inducer choke and a gas furnace employing the furnace inducer choke. In one embodiment, the furnace inducer choke includes: (1) a choke body configured to engage a furnace inducer blower, the choke body having an opening extending entirely therethrough to limit an amount of combustion air entering a furnace that the furnace inducer blower is attached, and (2) a tab protruding from the choke body a distance sufficient to identify the opening when the choke body and furnace inducer blower are installed in the furnace.

A condensate drain system for a heating, ventilation, and/or air conditioning (HVAC) system includes a heat exchanger having a plurality of tubes configured to receive ambient air and fluidly coupled to a drain via a conduit, a valve positioned along the conduit between the plurality of tubes and the drain, where the valve is configured to enable a flow of condensate from within the plurality of tubes toward the drain in an open position and the block the flow in a closed position, and a controller configured to adjust a position of the valve based on feedback indicative of an operational state of the HVAC system.