Hello dear community,
I am currently considering the issue of domestic hot water heating.
Photovoltaics and a ground source heat pump are almost certainly going to be installed. Now I am wondering what the most efficient way to heat domestic hot water is: using the ground source heat pump or an additional hot water heat pump?
How efficient is a ground source heat pump at heating domestic hot water during the summer? After all, the ground temperature is cooler than the ambient air temperature.
Hot water heat pumps have the additional benefit in summer of cooling the air, and there are apparently models available that are combined with ventilation systems.
In that case, the ground source heat pump could be turned off completely in summer, which might extend its lifespan. But of course, this would also mean adding more equipment that could potentially fail.
I tend to prefer as little technology as necessary. Are there any recommended combined systems that provide heating, ventilation, and hot water production all in one? I know that’s asking for three features at once...
I would be very grateful for any suggestions and experiences.
Best regards,
Judyyy
I am currently considering the issue of domestic hot water heating.
Photovoltaics and a ground source heat pump are almost certainly going to be installed. Now I am wondering what the most efficient way to heat domestic hot water is: using the ground source heat pump or an additional hot water heat pump?
How efficient is a ground source heat pump at heating domestic hot water during the summer? After all, the ground temperature is cooler than the ambient air temperature.
Hot water heat pumps have the additional benefit in summer of cooling the air, and there are apparently models available that are combined with ventilation systems.
In that case, the ground source heat pump could be turned off completely in summer, which might extend its lifespan. But of course, this would also mean adding more equipment that could potentially fail.
I tend to prefer as little technology as necessary. Are there any recommended combined systems that provide heating, ventilation, and hot water production all in one? I know that’s asking for three features at once...
I would be very grateful for any suggestions and experiences.
Best regards,
Judyyy
U
Ulrich Fuckert7 Dec 2016 07:53We have a heat pump that we use to heat the building and produce hot water. There are four of us in the household, and we have a 300-liter (79-gallon) buffer tank. Even during the hottest summers, we have had no issues so far.
Judyyy schrieb:
Now I’m wondering, what is the most efficient way to heat domestic hot waterUsing the existing or already planned heat generators makes the most sense. Adding another system alongside a ground source heat pump is unnecessary, even if it might be slightly more efficient (which I doubt). That would reduce the monthly hot water cost from about €15 to €12, but involves installation effort, purchase costs, and space requirements.
Forget about active cooling with fans, unless it’s a proper air conditioning system with adequate cooling capacity. The effect is minimal, while installation effort is relatively high. If you’re already planning a ground source heat pump, consider passive cooling. Although its effect is small, it’s noticeable, consumes much less electricity, and also helps regenerate the ground probes, which improves their efficiency in winter. Passive cooling is usually an add-on module for the heat pump and costs around €1000-2000.
Hello everyone,
we are planning the same system, building to KfW 40+ standard. Heat pump with geothermal probes for heating (underfloor heating) and domestic hot water (300-liter (79-gallon) tank, 4 persons), but a second unit is not cost-effective. Controlled mechanical ventilation is separate, photovoltaic system and battery storage due to 40+ subsidy with 2 units.
we are planning the same system, building to KfW 40+ standard. Heat pump with geothermal probes for heating (underfloor heating) and domestic hot water (300-liter (79-gallon) tank, 4 persons), but a second unit is not cost-effective. Controlled mechanical ventilation is separate, photovoltaic system and battery storage due to 40+ subsidy with 2 units.
T
toxicmolotof7 Dec 2016 12:17We used 329 kWh of electricity for the heat pump over the six summer months (without heating). At an electricity price of 23.35 cents, this amounts to a total of 76.82 euros or about 12.80 euros per month. We are using a 200-liter (53-gallon) storage tank.
Since we have a photovoltaic system, the water is basically heated for free during sunlight hours (excluding taxes and investment costs).
Additional technology can hardly be cheap enough to make sense at all. A geothermal heat pump has a COP above 4... so what could an additional system realistically achieve? You might as well use solar thermal, but that doesn’t really make sense either.
Since we have a photovoltaic system, the water is basically heated for free during sunlight hours (excluding taxes and investment costs).
Additional technology can hardly be cheap enough to make sense at all. A geothermal heat pump has a COP above 4... so what could an additional system realistically achieve? You might as well use solar thermal, but that doesn’t really make sense either.
Similar topics