Category : 2.1. Space heating / 2.2. Ventilation / 2.3. Domestic hot water production Compact unit with heat pump
General description In a compact unit, all the building services are governed by one appliance: ventilation, heating (or cooling) and domestic hot water. Air is the most important element: it is the medium that transports the heat on the supply side, and it is the heat source of the heat pump on the exhaust side. In a first step, the exhaust air passively pre‐heats the supply of fresh air through an air‐to‐air counter flow heat exchanger. In a second step, the heat pump extracts the remnant energy for a large part consisting of latent heat) from the exhaust air. The heat pump supplies energy to heat up the domestic hot water storage tank, used for water & heating the supply air. The energy available from the exhaust air will absolutely not be sufficient for the heating of the ventilation air and domestic hot water supply of a conventional dwelling. The use of a compact unit with heat pump only makes sense for a building that fulfills passive house standards. For additional heating, ground heat exchangers, thermal solar systems, electricity or external air‐to‐air heat pumps can be connected to the system. Compact unit with heat pump: basic principle (source: Passive House Institute). Availability on the market In Belgium: yes Abroad: yes Advantages 
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If the passive pre‐heating of the supply of fresh air is not sufficient for the entire heating of the building, it does at least lower the heating costs by recovering the otherwise lost heat in the exhaust air. The unit is fairly compact (in one typical case 2060x900x600 cm for a maximum ventilation rate of 320m3/h and a boiler volume of 180l). Disadvantages / Constraints / Related issues 
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The energy available from the exhaust air is not sufficient for the heating and domestic water production of a conventional or standard insulated building. So far the tank is delivered with glazed heater, but work is in progress to deliver a stainless tank Lack of data regarding heat recovery from the ventilation plant References 
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www.nilanbelgium.be http://www.passivhaustagung.de/Passive_House_E/compact_system_passive_house.htm www.kvt.no Disclaimer: This publication is edited with the largest possible care, using available public sources and producers’ information. Attention should be paid to applicability in local circumstances and additional considerations (long term performance, state of validation, …). The One Stop Shop authors cannot be held responsible for any damage to property or persons as a result of the use of this publication and/or its content.