The method of modifying an air conditioner for heating takes advantage of the features and operation of a conventional limited space air conditioner, such as a portable room air conditioner. A hood or manifold is placed over the vents or grille that normally exhausts cold air into the room, and a flexible duct hose is connected between the hood or duct and an exhaust vent installed in a window or ceiling to exhaust cold air produced by the air conditioner outside the building. The duct from the condenser or hot air side of the air conditioner, which would normally be exhausted outside the building, is open to the room in need of heating. Thus, the hot air produced by normal operation of the air conditioner is used to heat the room.

An HVAC system includes an evaporator coil disposed between a return air duct and a supply air duct. The system includes a compressor fluidically connected to the evaporator coil, and a blower for providing a flow of air through the HVAC system. The HVAC system includes a supply air recirculation line with a recirculation damper and an evaporator bypass line with a bypass damper. A controller of the HVAC determines a recirculation portion of a flow of air and causes the recirculation damper to move to divert the recirculation portion to the recirculation line, so the air recirculates through the HVAC system. The controller determines a bypass portion of a flow of air and causes the bypass damper to move to divert the bypass portion to the bypass line, so the bypass portion does not contact the evaporator coil.

An HVAC system includes an evaporator coil disposed between a return air duct and a supply air duct. The system includes a compressor fluidically connected to the evaporator coil, and a blower for providing a flow of air through the HVAC system. The HVAC system includes a supply air recirculation line with a recirculation damper and an evaporator bypass line with a bypass damper. A controller of the HVAC determines a recirculation portion of a flow of air and causes the recirculation damper to move to divert the recirculation portion to the recirculation line, so the air recirculates through the HVAC system. The controller determines a bypass portion of a flow of air and causes the bypass damper to move to divert the bypass portion to the bypass line, so the bypass portion does not contact the evaporator coil.

A heat transfer system that includes one or more heat exchangers and one or more variable control pumps that control flow through the one or more heat exchangers. At least one variable control pump is on the source side of the heat exchanger for controlling flow of a first circulation medium and at least one flow controlling mechanical device is on the load side of the heat exchanger for controlling flow of a second circulation medium. Sensors are used for detecting variables of the first circulation medium and the second circulation medium. At least one controller is configured to control at least one parameter of the first circulation medium or the second circulation medium by controlling at least one of the variable control pump or the flow controlling mechanical device using a feed forward control loop calculated from the detected variables to achieve control of the at least one parameter.

An air conditioning unit is disclosed. The air conditioning unit may include a makeup air system having a makeup air duct with a first end and a second end. The makeup air duct may be separate structure built in a bottom plate of the air conditioning unit and define an air flow passage in fluid communication between the first end and the second end to allow makeup air to flow therethrough.

An air conditioning unit is disclosed. The air conditioning unit may include a makeup air system having a makeup air duct with a first end and a second end. The makeup air duct may be separate structure built in a bottom plate of the air conditioning unit and define an air flow passage in fluid communication between the first end and the second end to allow makeup air to flow therethrough.

A heating, ventilation, and/or air conditioning (HVAC) system includes a heat exchanger configured to exchange heat between a refrigerant and an air flow, a blower configured to induce the air flow across the heat exchanger, and a control board configured to receive an input indicative of a presence of refrigerant external to the heat exchanger and adjust operation of the blower based on the input.

A heating, ventilation, and/or air conditioning (HVAC) system includes a heat exchanger configured to exchange heat between a refrigerant and an air flow, a blower configured to induce the air flow across the heat exchanger, and a control board configured to receive an input indicative of a presence of refrigerant external to the heat exchanger and adjust operation of the blower based on the input.

A space conditioning system and method for monitoring electrical parameters and/or thermodynamic parameters relating to the heat of extraction/rejection or power consumption of the system and to communicate the monitored parameters to an external device.

A space conditioning system and method for monitoring electrical parameters and/or thermodynamic parameters relating to the heat of extraction/rejection or power consumption of the system and to communicate the monitored parameters to an external device.