ᐅ Ground Source Heat Pump – What to Watch for When Reviewing a Quote (Single-Family Home, New Build, KfW 70 Standard)
Created on: 31 Jan 2014 08:21
L
Lacos
Hello everyone,
We are planning to build with a general contractor (single-family house, about 136 sqm (1463 sq ft), gable roof, ≤KFW70) and would like to enter the final negotiations with the last 2 or 3 points.
The construction descriptions each list ground source heat pumps (brand name + buffer tank), but without much detail. I would like to ask for your recommendations in this area.
Since brand names probably shouldn’t be mentioned here:
A brine-to-water ground source heat pump with a COP of 4.7 is specified (integrated domestic hot water tank of 185L (49 gallons)). Additionally, a buffer tank, probably between 200 - 300L (53 - 79 gallons), is planned.
1. Is this combination reasonable?
2. What should generally be considered with heat pumps? I definitely want to install a heat meter and a separate electricity meter. What else should be taken into account?
3. Which combination do you consider the most practical (e.g., size of the buffer tank, etc.) for a household of two people (both working, possibly one child in a few years)?
Thank you very much in advance,
Lacos
We are planning to build with a general contractor (single-family house, about 136 sqm (1463 sq ft), gable roof, ≤KFW70) and would like to enter the final negotiations with the last 2 or 3 points.
The construction descriptions each list ground source heat pumps (brand name + buffer tank), but without much detail. I would like to ask for your recommendations in this area.
Since brand names probably shouldn’t be mentioned here:
A brine-to-water ground source heat pump with a COP of 4.7 is specified (integrated domestic hot water tank of 185L (49 gallons)). Additionally, a buffer tank, probably between 200 - 300L (53 - 79 gallons), is planned.
1. Is this combination reasonable?
2. What should generally be considered with heat pumps? I definitely want to install a heat meter and a separate electricity meter. What else should be taken into account?
3. Which combination do you consider the most practical (e.g., size of the buffer tank, etc.) for a household of two people (both working, possibly one child in a few years)?
Thank you very much in advance,
Lacos
B
Bauexperte15 Feb 2014 11:03Hello,
This modern, unchecked urge to tinker by potential homeowners is rarely productive and usually leads to needing a professional to come back; often on holidays or weekends.
Regards, Bauexperte
Mycraft schrieb:This cannot be said often enough; thank you! However, I would like to extend this to all systems that require professional adjustment.
Especially with heat pumps, every setting should be considered carefully three times... so controlling them via PC, etc., is rather uninteresting... once the system is running properly, you shouldn’t adjust it anymore...
This modern, unchecked urge to tinker by potential homeowners is rarely productive and usually leads to needing a professional to come back; often on holidays or weekends.
Regards, Bauexperte
waldorf schrieb:
..... This cannot be achieved by a control system based solely on outside temperature.... Correct, which is why nested control systems are basically the standard today! The outside temperature-based control generally provides a rough guideline. Room-specific heating curve controls represent the actual conditions in each room. Additional system return temperature monitoring/control influences, for example, the output capacity in gas condensing boilers and heat pumps when operating modulating! However, all of this requires sufficient planning and sizing (heating load, room heating loads, heating surfaces, hydraulics)! Whether forecasted weather data can compensate for deficits in the basic parameters, I rather doubt! Best regards
waldorf schrieb:
... with such large glazed areas, controlling based on the weather forecast is an absolute must, since the heating demand and thus the room temperature are higher at +5°C (41°F) with wind and rain than at -10°C (14°F) with bright sunshine. A control system that relies solely on outside temperature cannot manage this.Hello,
I have a slightly different view on this. While the self-regulating effect of underfloor heating should not be overestimated, it does contribute to balancing the temperature to some extent, as heat is transferred to the more "shaded" rooms. Secondly, the mechanical ventilation with heat recovery also helps to balance indoor temperatures. Moreover, shading plays a major role—especially with large glass surfaces—and this is an essential consideration for targeted planning.
Before experimenting here with weather-forecast-based control or any iPhone apps, I simply lower the blinds during strong sunlight—or, if needed, control them via a sensor. We have a southwest orientation and a lot of glass on that side, so we rely on blinds. Together with the self-regulating effect of underfloor heating and controlled mechanical ventilation, this works very well.
Best regards
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