Hello everyone,
I have the following description from the general contractor. I notice that the domestic hot water storage tank is much smaller than in other examples here in the forum. Does this make sense?
Are there any experiences with this type of unit(s)?
Is a circulation system necessary?
Which screed is recommended for underfloor heating?
(About the house: 166 m² (1786 sq ft), approx. 9 x 11 m (30 x 36 ft), KFW 55)
Heating system
Vaillant system:
Gas condensing boiler with integrated solar system according to DIN/EN 677, auroCOMPACT series in compliance with the energy saving regulation, featuring a stainless steel heat exchanger. Rated heating output is approximately 3.3 to 14.7 kW. Depending on the outdoor temperature, a weather-compensated solar system controller type multiMATIC regulates the temperature level. Heating cycles and domestic hot water production can be programmed individually via a timer.
Air/exhaust system:
The air/exhaust system for the sealed combustion condensing units is a concentric air/flue pipe system routed through the roof.
Domestic hot water
Vaillant system:
The house’s domestic hot water supply is central without circulation pipes. For supplying the bathroom, guest toilet, and kitchen, the described gas condensing boiler with integrated 190 L (50 US gallons) stratified hot water storage tank is combined with three system-matched flat-plate solar collectors of type auroTHERM VFK 145 V/H, mounted on the roof with a total collector area of about 7.5 m² (81 sq ft). A thermostatic mixing valve is provisioned to prevent scalding.
Underfloor heating:
Warm water underfloor heating designed based on heating demand calculation, using plastic piping on insulation boards with room temperature control (surface-mounted thermostat).
Depending on the contractor’s choice, either a cement or anhydrite screed will be installed.
One heating circuit manifold per floor is planned, which will be installed flush with the wall.
Thank you,
h4nnes
I have the following description from the general contractor. I notice that the domestic hot water storage tank is much smaller than in other examples here in the forum. Does this make sense?
Are there any experiences with this type of unit(s)?
Is a circulation system necessary?
Which screed is recommended for underfloor heating?
(About the house: 166 m² (1786 sq ft), approx. 9 x 11 m (30 x 36 ft), KFW 55)
Heating system
Vaillant system:
Gas condensing boiler with integrated solar system according to DIN/EN 677, auroCOMPACT series in compliance with the energy saving regulation, featuring a stainless steel heat exchanger. Rated heating output is approximately 3.3 to 14.7 kW. Depending on the outdoor temperature, a weather-compensated solar system controller type multiMATIC regulates the temperature level. Heating cycles and domestic hot water production can be programmed individually via a timer.
Air/exhaust system:
The air/exhaust system for the sealed combustion condensing units is a concentric air/flue pipe system routed through the roof.
Domestic hot water
Vaillant system:
The house’s domestic hot water supply is central without circulation pipes. For supplying the bathroom, guest toilet, and kitchen, the described gas condensing boiler with integrated 190 L (50 US gallons) stratified hot water storage tank is combined with three system-matched flat-plate solar collectors of type auroTHERM VFK 145 V/H, mounted on the roof with a total collector area of about 7.5 m² (81 sq ft). A thermostatic mixing valve is provisioned to prevent scalding.
Underfloor heating:
Warm water underfloor heating designed based on heating demand calculation, using plastic piping on insulation boards with room temperature control (surface-mounted thermostat).
Depending on the contractor’s choice, either a cement or anhydrite screed will be installed.
One heating circuit manifold per floor is planned, which will be installed flush with the wall.
Thank you,
h4nnes
Grym schrieb:
I thought you had an air-to-water heat pump? How is it supposed to produce 60 degrees?Do you know any other nordlys? [emoji1]
Of course, an air-to-water heat pump can also produce 60 degrees Celsius (140°F) hot water without an electric heating element. It just isn’t economically sensible.
Check the technical datasheets. For example, the Vaillant Arotherm can reach up to 60 degrees Celsius (140°F) for 5 kW air-to-water heat pump models and up to 63 degrees Celsius (145°F) for 8–11 kW models.
berny schrieb:
With 3 collectors, I would recommend at least a 300-liter (79-gallon) tank for a south-facing roof with an inclination between 25° and 45°.
Or better yet, one fewer collector with a 190-liter (50-gallon) tank. Otherwise, there might be a risk of overheating in summer if it’s not a drainback system.We have a south-facing roof (exactly 0°) with a 25° (9-inch) pitch.
I also read the following in another thread:
“Solar panels need to be cooled relatively early in summer, meaning that little hot water is needed but heat must be removed from the panels → increased electricity and water costs without added benefit.”
Are these systems really that “inefficient” and unable to handle excess energy differently?
Wouldn’t the system override my set desired temperature and stop heating if there is excess energy? What exactly happens?
At the moment, 190 liters (50 gallons) would definitely be enough. But the kids are growing… Is it sensible to upgrade later on, or do you just accept that gas heating runs more often or go straight for a larger storage tank?
What about using solar thermal for heating support? Does that make sense?
First: We use gas plus solar for hot water.
Second: Our storage tank is way too big for us at 300 liters (80 gallons). We never use it all. I wish we had chosen a smaller one... but no one advised us. The mentality was "the bigger, the better"… smile.
Heating support: Don’t bother. It’s expensive and the control technology is prone to problems. It doesn’t help. When you have a lot of heating, there’s little sun anyway. Karsten
Second: Our storage tank is way too big for us at 300 liters (80 gallons). We never use it all. I wish we had chosen a smaller one... but no one advised us. The mentality was "the bigger, the better"… smile.
Heating support: Don’t bother. It’s expensive and the control technology is prone to problems. It doesn’t help. When you have a lot of heating, there’s little sun anyway. Karsten
The collector surfaces are required to comply with the energy saving regulations. You have the 300-liter (79-gallon) storage tank to ensure that enough heat is actually drawn.
All of this is simply a consequence of choosing gas. You have to accept some disadvantages either way.
All of this is simply a consequence of choosing gas. You have to accept some disadvantages either way.
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