HVAC apparatus, method, and system

A method of providing conditioned air to a room comprising:

• a. providing a heat pump outside the room in communication with outdoor air;
• b. providing an air handler unit in communication with the room, the air handler unit including a heating/cooling coil in operative communication with the heat pump and a secondary heating coil in operative communication with a secondary heat source;
• c. monitoring for a request for heat to the room;
• d. monitoring outdoor air ambient temperature;
• and
• e. monitoring supply air temperature at the air handler unit, and providing heated air to the room from the heat pump and heating/cooling coil and/or from the secondary heat source and secondary heat coil based on a predetermined supply air temperature;
• and
• f. upon a request for heat:
• i. providing heated air to the room from the heat pump and heating/cooling coil when outdoor air ambient temperature is not indicative of requiring a defrost cycle for the heat pump;
• ii. providing heated air to the room from the secondary heat source and secondary heat coil when outdoor air ambient temperature is indicative of requiring a defrost cycle for the heat pump;
• iii. so that heated air is available to the room without need for defrosting of the heat pump.

An HVAC system for providing conditioned air to a space to be heated comprising:

• a. a heat pump sub-system in communication with outside atmospheric air;
• b. an air handler sub-system with a blower to move air and a heating/cooling coil to add or remove heat from the space to be heated in communication with the heat pump sub-system;
• c. a booster heater module in communication with the air handler subsystem comprising:
• i. a housing having opposite narrow side walls, opposite wide side walls, and opposite end walls defining an interior space with an interior temperature sensor;
• ii. an air path between an air inlet to the interior space and an air outlet from the interior space;
• iii. a hydronic coil mounting interface on the housing adapted for mounting of a hydronic heating coil along the air path;
• iv. connections on the hydronic coil for operative connection to a hot water source;
• and
• v. wherein the air inlet of the booster heater module is in fluid communication with supply air from the air handler unit and the air outlet of the booster heater module becomes the supply air outlet for the air handler sub-system and the booster heater module to the space to be heated;
• d. a thermostat;
• e. a control sub-system operatively connected to the heat pump sub-system, the combination of the air handler sub-system, the booster heater module, and the thermostat, the control sub-system programmed to:
• i. monitor supply air temperature at the air handler unit;
• and
• ii. provide heated air to the space to be heated from the heat pump and/or from the booster heater module based on a predetermined supply air temperature;
• and
• f. wherein upon a call for heat from the thermostat, the control sub-system is programmed to:
• i. operate the heat pump sub-system and air handler sub-system to provide heated air from the heating/cooling coil to the room when the temperature sensor senses ambient outdoor temperatures above a predetermined temperature;
• and
• ii. turn off the heat pump and operate the booster heater module and air handler sub-system to provide heated air from the booster heater module when the interior temperature sensor senses ambient outdoor temperatures below the predetermined temperature.