Hi everyone,
we are building a small solid house with a general contractor. Originally, the plan was to have a gas boiler with a controlled ventilation system.
Now that we finally have an installer assigned, he told us there is no space for controlled ventilation!
This is quite short notice since the excavator is already on site, and digging for the foundation will probably start on Monday.
The general contractor has presented us with the following options:
Option 1:
- Gas condensing boiler with solar thermal system
(Photovoltaic system does not make sense here!)
Requirements:
o Flue pipe (either on the exterior wall or in the cloakroom niche)
o Buffer tank
o Expansion vessel
o Condensing boiler
o Piping for solar system up to the roof
Requires a lot of space
Option 2:
- Gas condensing boiler with ventilation (just sufficient for energy saving regulation calculations)
(Photovoltaic system does not make sense here!)
Requirements:
o Flue pipe (either on the exterior wall or in the cloakroom niche)
o Buffer tank
o Expansion vessel
o Condensing boiler
o Ventilation system (ceiling-mounted)
Basically no space available
Option 3:
- Air-to-water heat pump with ventilation
(Photovoltaic system can be added later – empty conduit to the roof)
Requirements:
o Buffer tank
o Expansion vessel
o Outdoor unit for air-to-water heat pump
o Ventilation system (ceiling-mounted)
o 10cm (4 inches) build-up in the sloped roof area needed for ventilation ducts
Option 4:
- Air-to-water heat pump without ventilation
(Energy saving regulation compliance is technically not a problem, but mechanical ventilation should possibly be ensured by e.g. window frame ventilation)
(Photovoltaic system can be added later – empty conduit to the roof)
Requirements:
o Buffer tank
o Expansion vessel
o Outdoor unit for air-to-water heat pump
Unfortunately, the additional costs for these options have not been communicated to us.
We are currently leaning towards option 4, but we are quite uncertain about these window frame ventilation solutions...
Have a nice Sunday
Marvin
we are building a small solid house with a general contractor. Originally, the plan was to have a gas boiler with a controlled ventilation system.
Now that we finally have an installer assigned, he told us there is no space for controlled ventilation!
This is quite short notice since the excavator is already on site, and digging for the foundation will probably start on Monday.
The general contractor has presented us with the following options:
Option 1:
- Gas condensing boiler with solar thermal system
(Photovoltaic system does not make sense here!)
Requirements:
o Flue pipe (either on the exterior wall or in the cloakroom niche)
o Buffer tank
o Expansion vessel
o Condensing boiler
o Piping for solar system up to the roof
Requires a lot of space
Option 2:
- Gas condensing boiler with ventilation (just sufficient for energy saving regulation calculations)
(Photovoltaic system does not make sense here!)
Requirements:
o Flue pipe (either on the exterior wall or in the cloakroom niche)
o Buffer tank
o Expansion vessel
o Condensing boiler
o Ventilation system (ceiling-mounted)
Basically no space available
Option 3:
- Air-to-water heat pump with ventilation
(Photovoltaic system can be added later – empty conduit to the roof)
Requirements:
o Buffer tank
o Expansion vessel
o Outdoor unit for air-to-water heat pump
o Ventilation system (ceiling-mounted)
o 10cm (4 inches) build-up in the sloped roof area needed for ventilation ducts
Option 4:
- Air-to-water heat pump without ventilation
(Energy saving regulation compliance is technically not a problem, but mechanical ventilation should possibly be ensured by e.g. window frame ventilation)
(Photovoltaic system can be added later – empty conduit to the roof)
Requirements:
o Buffer tank
o Expansion vessel
o Outdoor unit for air-to-water heat pump
Unfortunately, the additional costs for these options have not been communicated to us.
We are currently leaning towards option 4, but we are quite uncertain about these window frame ventilation solutions...
Have a nice Sunday
Marvin
So, I’ve just spoken with the architect and the installer.
The architect couldn’t offer any concessions on the price. In other words, we would have to pay the additional €4000 net for the air-to-water heat pump, as specified in the contract.
The installer explained why the mechanical ventilation system with heat recovery won’t fit. It’s not really about the device size, but rather that he can’t route the four ducts through the small utility room properly (only “half-assed”).
He recommends the air-to-water heat pump along with two single-room ventilation units with heat recovery instead. He also thinks the trickle vents in the window frame are pointless.
So financially, it looks like this:
+ €4000 air-to-water heat pump
- €12,000 mechanical ventilation system with heat recovery
- €3000 gas connection
+ €X single-room ventilation units
So, there is some cost saving, but it involves giving up the comfort of the mechanical ventilation system.
(The terrace awning should be affordable then.)
The space under the stairs is not enclosed; it should be used as a shoe storage/coatroom.
And yes, the guest/office room will definitely be used as storage space for now.
The architect couldn’t offer any concessions on the price. In other words, we would have to pay the additional €4000 net for the air-to-water heat pump, as specified in the contract.
The installer explained why the mechanical ventilation system with heat recovery won’t fit. It’s not really about the device size, but rather that he can’t route the four ducts through the small utility room properly (only “half-assed”).
He recommends the air-to-water heat pump along with two single-room ventilation units with heat recovery instead. He also thinks the trickle vents in the window frame are pointless.
So financially, it looks like this:
+ €4000 air-to-water heat pump
- €12,000 mechanical ventilation system with heat recovery
- €3000 gas connection
+ €X single-room ventilation units
So, there is some cost saving, but it involves giving up the comfort of the mechanical ventilation system.
(The terrace awning should be affordable then.)
The space under the stairs is not enclosed; it should be used as a shoe storage/coatroom.
And yes, the guest/office room will definitely be used as storage space for now.
M4rvin schrieb:
The space under the stairs isn’t enclosed; it should be used as a shoe storage / wardrobe area.On top of that: it’s a constant mess under the stairs. At least with a door, you can keep it out of sight.
B
boxandroof25 Feb 2019 16:29Please plan the air-to-water heat pump early, especially the underfloor heating, which should be designed for a maximum temperature of 30°C (86°F). Otherwise, it might be better to choose gas, as there is less room for error.
And please define the final ventilation concept even earlier! It is crucial for selecting the air-to-water heat pump (heating load). There are good and bad decentral units, and the quality of the installation is just as important.
And please define the final ventilation concept even earlier! It is crucial for selecting the air-to-water heat pump (heating load). There are good and bad decentral units, and the quality of the installation is just as important.
B
boxandroof25 Feb 2019 16:38By the way, gas can also be used with decentralized ventilation units without solar thermal systems, instead of an air-to-water heat pump.
O
Obstlerbaum25 Feb 2019 17:21boxandroof schrieb:
Please plan the air-to-water heat pump early in the process, especially have the underfloor heating designed for a maximum flow temperature of 30°C (86°F), otherwise gas heating might be a safer choice as it leaves less room for errors. A flow temperature of 30°C (86°F) is not always achievable; in small rooms, you quickly reach limitations. Not every building is constructed to KfW40+ standards...
Addendum, in case it’s unclear: I am referring to the flow temperature at the standard outdoor temperature.
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