ᐅ Underfloor Heating or Air Heating in New Construction? (KFW55)
Created on: 22 Apr 2017 13:23
W
Wissi
Hello everyone!
Our building project is becoming more concrete, and we have been considering for some time which heating system to use.
The options we are looking at are:
Schwörerhaus "Wärme GewinnTechnik" WRG134HK:
Underfloor heating:
A few more details about our house:
There are many details to consider, so now the question is: How would you decide... and why?
What would you recommend?
Our building project is becoming more concrete, and we have been considering for some time which heating system to use.
The options we are looking at are:
Schwörerhaus "Wärme GewinnTechnik" WRG134HK:
- Air-to-air small heat pump (integrated into the ventilation system)
- Additional small PTC heating elements at the outlets
- Summer bypass available (slightly cooling effect)
- Domestic hot water via: "Drinking water heat pump Aerotop DHW250"
- Water tank: 250 liters (66 gallons) with electric auxiliary heating
- Cost approx.: 12,000 Euros
Underfloor heating:
- Air-to-water heat pump Buderus "Logatherm WLW196i IR"
- Here too, there is supposed to be a possibility for a slight cooling effect
- Annual performance factor specified as ">=4.5"
- Domestic hot water also provided by this unit
- Water tank: 300 liters (79 gallons) (no mention of electric auxiliary heating)
- Cost approx.: 25,000 Euros
A few more details about our house:
- Ground floor area: 74.07 m² (797 sq ft)
- Usable floor area: 116.29 m² (1,252 sq ft) plus 69 m² (742 sq ft) cellar
- Built on a slope facing south
- Located near the Sauerland region – winters can be cold, wet, and long
There are many details to consider, so now the question is: How would you decide... and why?
What would you recommend?
Fortunately, it is not a split unit. We would rather avoid installing an outdoor module… that saves both our nerves and the neighbor’s.
As for the demand, I understand that this unit can modulate freely.
Here are some data that you (or others) might find more useful than I do:
COP: 4.0 – 4.2
Standard outdoor temperature: -16°C (3°F)
Annual performance factor: 4.5
Modulation (depending on system size):
6 kW (from 2 to 6 kW)
8 kW (from 3 to 8 kW)
11 kW (from 5.5 to 11 kW)
14 kW (from 5.5 to 14 kW)
We think we will need one of the smaller systems for just under 120 m² (approximately 1300 sq ft) of living space.
In the end, it is important to us that the unit is as efficient as possible (within what is achievable for an air-source heat pump), can possibly be connected to a photovoltaic system later on (fortunately this is possible), and, of course, that it has a long service life.
As for the demand, I understand that this unit can modulate freely.
Here are some data that you (or others) might find more useful than I do:
COP: 4.0 – 4.2
Standard outdoor temperature: -16°C (3°F)
Annual performance factor: 4.5
Modulation (depending on system size):
6 kW (from 2 to 6 kW)
8 kW (from 3 to 8 kW)
11 kW (from 5.5 to 11 kW)
14 kW (from 5.5 to 14 kW)
We think we will need one of the smaller systems for just under 120 m² (approximately 1300 sq ft) of living space.
In the end, it is important to us that the unit is as efficient as possible (within what is achievable for an air-source heat pump), can possibly be connected to a photovoltaic system later on (fortunately this is possible), and, of course, that it has a long service life.
Oh sorry, I only glanced at it briefly, of course the unit is installed indoors. It has only been on the market for a very short time. But that doesn’t change my general statement. A good heating engineer and a well-designed overall system are extremely important, no matter who manufactures the unit. They all heat water in almost the same way. Otherwise, the smallest unit will probably be sufficient for you. I wouldn’t place complete trust in the COP and annual performance factor figures, but that applies to all manufacturers!
Regarding noise: this unit will have both an air intake and an air outlet grill on the exterior wall; air-to-water heat pumps are never completely silent since they have to move large volumes of air... so the neighbor will always hear something—especially if the air outlet faces their direction. Be very careful during installation to ensure the air outlet duct is perfectly insulated; if there are mistakes, you’ll end up with dark mold on the walls after a few years. I’ve seen that happen myself.
If you have a bit of extra money: install photovoltaic panels on the roof during the house construction. The scaffolding is already up, the electrician is already in the house, and so on...
Regarding noise: this unit will have both an air intake and an air outlet grill on the exterior wall; air-to-water heat pumps are never completely silent since they have to move large volumes of air... so the neighbor will always hear something—especially if the air outlet faces their direction. Be very careful during installation to ensure the air outlet duct is perfectly insulated; if there are mistakes, you’ll end up with dark mold on the walls after a few years. I’ve seen that happen myself.
If you have a bit of extra money: install photovoltaic panels on the roof during the house construction. The scaffolding is already up, the electrician is already in the house, and so on...
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