Abstract: Embodiments described herein generally relate to a domestic hot water (DHW) preheater operable to supply domestic hot water to a structure and/or to preheat a cold return of a space heating system.

Abstract: Embodiments described herein include systems, devices, and methods for improved heating, ventilation, and air conditioning. In some embodiments, a system includes a housing, a thermal mass unit disposed in the housing and configured to thermally couple to a room side of a heat pump that is disposed outside of the housing, and a thermal coupling device coupled to the thermal mass unit and configured to transfer heat between the thermal mass unit and the room side of the heat pump. In some embodiments, the system can further include a heat exchanger thermally coupled to the thermal mass unit and the thermal coupling device. In some embodiments, the heat exchanger can transfer heat between the thermal mass unit and the thermal coupling device.

Abstract: Embodiments described herein generally relate to a domestic hot water (DHW) preheater operable to supply domestic hot water to a structure and/or to preheat a cold return of a space heating system.