May. 29, 2008 - Low-energy and passive houses are superinsulated and air-tight buildings where the space heating demand is considerably lower than that of buildings constructed in accordance with common buildings codes. Due to the low space heating demand, the annual heating demand for domestic hot water (DHW) typically constitutes 50 to 85% of the total annual heating demand in the residence.A heat pump system can be used to cover the heating demands in low-energy houses and passive houses. The heat pump system can be designed as stand-alone systems, i.e. a heat pump water heater (HPWH) in combination with separate units for space heating, or be an integrated unit for combined space heating and hot water heating (IHPS). Due to compact design, the latter system is most likely to achieve the lowest investment and installation costs and with that the best profitability.
