Hello! In the Berlin area, both types of heat pumps are highly recommended (after several consultations). The question now is, from your neutral perspective, which option is the better choice. We would like to use the heat pump alone for heating and domestic hot water in a 250 m² (2,690 sq ft) living area (the basement is to be partially heated), without any additional devices (so, for example, no separate unit for hot water). Is this even realistic? There are very conflicting statements about this. One person says the heat pump should only be used for underfloor heating and that an additional gas condensing boiler should be installed for hot water (which I personally think is complete nonsense), while another says it is no problem at all. However, the latter also needs to be viewed with some skepticism since everything must be precisely calculated. As I said, my main question is about the basic choice between geothermal (ground source) or water-to-water heat pumps (both with deep drilling).
Goal: Supply underfloor heating for approximately 250 m² (2,690 sq ft) and produce domestic hot water for 2 adults and 2 children (the children are still in progress ;-))
Goal: Supply underfloor heating for approximately 250 m² (2,690 sq ft) and produce domestic hot water for 2 adults and 2 children (the children are still in progress ;-))
Hello,
With brine heat pumps, there is the possibility to use different types of sources. In addition to the typical vertical borehole(s) — multiple boreholes are better than one, but, unfortunately, also more expensive ;-) — surface or trench collectors can be used. With these, the high costs of source installation can be significantly reduced through owner participation.
Ultimately, it depends on the actual demand for heating and hot water. The higher the demand, the more necessary it is to achieve a high seasonal performance factor; the lower the demand, the less economically noticeable the seasonal performance factor of the heat pump solution becomes.
For very well-insulated buildings, digging or drilling into the ground may be unnecessary; a fully modulating air-source heat pump is sufficient here.
Best regards.
Chris82 schrieb:Who provided the consultation? ;-)
.... In the Berlin area, both types of heat pumps are particularly recommended (after several consultations).
Chris82 schrieb:Both are right, but with quite different approaches ;-) The fact is that producing hot water with a heat pump is inherently less efficient, as it requires a higher supply temperature compared to the precise design of the heating surfaces (heating operation). The seasonal performance factor (SPF) for hot water is always lower than for heating, provided the latter is properly sized and planned. However: in many cases, the energy consumption, not capacity, for hot water production is about one-third of what is needed for heating, depending on the building envelope’s heat transfer coefficient (Ht value). The reduction of the overall seasonal performance factor is therefore usually, but not always, limited.
....One says you should only use the heat pump for underfloor heating and install an additional gas condensing boiler for hot water (which I personally think is complete nonsense), the other says there’s absolutely no problem with it.
Chris82 schrieb:Correct!
....Which again has to be viewed skeptically, as everything must be calculated precisely.
Chris82 schrieb:Water-to-water heat pumps can theoretically achieve a higher seasonal performance factor than brine heat pumps, as the source can provide a higher temperature level. However, everything must be right here, especially water quality (iron deposits in supply and/or injection wells). Many plans fail because of this. According to manufacturer COP values based on EN 14511, the energy use of the source circulation pump must be included. It’s no clairvoyance to see that the boundary conditions are particularly favorable here in order to reach the high COP values. In practice, these are rarely achieved, mostly due to water quality or hydraulic issues. This is a risk the building owner has to accept ;-)
....For me, the fundamental question is geothermal or water-to-water heat pump (both with deep boreholes).
With brine heat pumps, there is the possibility to use different types of sources. In addition to the typical vertical borehole(s) — multiple boreholes are better than one, but, unfortunately, also more expensive ;-) — surface or trench collectors can be used. With these, the high costs of source installation can be significantly reduced through owner participation.
Ultimately, it depends on the actual demand for heating and hot water. The higher the demand, the more necessary it is to achieve a high seasonal performance factor; the lower the demand, the less economically noticeable the seasonal performance factor of the heat pump solution becomes.
For very well-insulated buildings, digging or drilling into the ground may be unnecessary; a fully modulating air-source heat pump is sufficient here.
Best regards.
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