ᐅ Exhaust air heat pump for heating and domestic hot water – experiences
Created on: 27 Jul 2011 16:22
R
regnatHello,
For a KfW EH70 house, this will most likely not work out well. The operating costs will probably be relatively high. For a Passive House (PH), the balance would look somewhat different.
Without precise calculations and sizing by an MEP engineer, reliable predictions cannot be made.
Best regards
regnat schrieb:The planner should be able to answer that question. Has a consumption forecast been created?
...does anyone have experience with an exhaust air heat pump for heating and domestic hot water? How high are the electricity costs?
regnat schrieb:Heat pumps depend on their energy source. An exhaust air heat pump can only use the energy previously put into the system. Where does that come from? A perpetual motion machine does not exist, although sellers of such systems often like to suggest otherwise.
...I was offered a Nibe F370 with underfloor heating for a KfW70 house with 120sqm (1292 sq ft). Is this option recommended?
For a KfW EH70 house, this will most likely not work out well. The operating costs will probably be relatively high. For a Passive House (PH), the balance would look somewhat different.
Without precise calculations and sizing by an MEP engineer, reliable predictions cannot be made.
Best regards
An air-to-water heat pump, typically used in a single-family home, circulates at least 1,200 m³ (1,400 yd³) of air per hour. From this volume of air, the required amount of heat can be generated for heating and domestic hot water for a household of four people. This works with well-developed systems and a properly insulated building envelope without the need for electric heating elements.
In contrast, an exhaust air heat pump only has a relatively small air volume of about 250 m³ (290 yd³) per hour available for the heat pump compressor, which often makes the use of direct electric backup heating necessary.
Therefore, it is generally advisable to avoid exhaust air heat pumps, as they tend to result in higher operating costs in the long term.
By the way, in noisy residential areas, the combination of an exhaust air heat pump with a decentralized ventilation system is not recommended. Noise is brought into the house through the supply air vents installed in the exterior walls.
Cold drafts near the supply air openings are another disadvantage.
Best regards
T.H.
In contrast, an exhaust air heat pump only has a relatively small air volume of about 250 m³ (290 yd³) per hour available for the heat pump compressor, which often makes the use of direct electric backup heating necessary.
Therefore, it is generally advisable to avoid exhaust air heat pumps, as they tend to result in higher operating costs in the long term.
By the way, in noisy residential areas, the combination of an exhaust air heat pump with a decentralized ventilation system is not recommended. Noise is brought into the house through the supply air vents installed in the exterior walls.
Cold drafts near the supply air openings are another disadvantage.
Best regards
T.H.
Thomas Heufers schrieb:
This works with mature systems and properly well-insulated building envelopes without using the electric heating element. Many things may work, but unfortunately, it is not very efficient. In well designed systems, the share of the electric heating element is just around 1% of the annual heating demand, so it is completely unproblematic.
Best regards
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