ᐅ Gas and Solar Thermal – Questions About the Proposal

Created on: 5 Nov 2017 21:56
H
h4nnes
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
berny7 Nov 2017 11:57
@h4nnes:
h4nnes schrieb:
("Depending on the contractor's choice, either a cement or anhydrite screed will be installed.")
Could you tell me who you are building with, feel free to send a private message? The wording is exactly the same in our scope of work...
H
h4nnes
7 Nov 2017 13:20
Joedreck schrieb:
It definitely depends on the floor plan. I would always design it so that you can avoid circulation space. That is also an energy waster for you.

Understood, thank you. According to the current plan, the main bathroom would be above the utility room and the guest bathroom directly next to the utility room. Only the kitchen would be on the opposite side of the house. I think that is manageable. So that works for now.
N
Nordlys
7 Nov 2017 13:47
Yes, warm water comes to the kitchen slowly. But how often do you actually need warm water there? Or is there no dishwasher? I’m sure there is one. Karsten
G
Grym
7 Nov 2017 14:38
Every time you place a cooking pot on the stove, you need hot water.

And I don’t really like washing my hands with water at 10°C (50°F).

But as I said, purely a comfort issue.
J
Joedreck
7 Nov 2017 18:24
I would discuss with the plumber about installing a pipe with a smaller diameter. This will reduce the installation time. The shower and bathroom will then sound fine!

It is true, it is a comfort feature. However, depending on the settings, it can become quite expensive to maintain, also because certain hygiene factors need to be taken into account.