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
No offense, but window rebates are just nonsensical when it comes to energy efficiency. You build an insulated, airtight house and then install windows with gaps to allow ventilation.
I also like Katja’s design and would suggest proposing it to the general contractor if you like it yourself.
Besides that, I’m a strong advocate of controlled mechanical ventilation with heat recovery. We have gas plus controlled ventilation ourselves. No solar, which from an economic perspective is the next weak point...
We have a demand of about 9 kWh per day for hot water. That’s roughly €200 per year at €0.06/kWh. With a solar system, I save two-thirds of the preheating costs, so around €150. Considering the system costs start at around €4000, anyone can calculate how long it takes to break even.
Even if I assume a heat demand of 15 kWh per day (there are only two of us), it still takes over 20 years for it to pay off.
If this complies with the energy-saving regulations (energy performance regulations / building codes), I would insist on gas plus controlled mechanical ventilation.
Without solar, it’s also a plus that you can skip the buffer tank, which is not the worst thing considering your space constraints.
I also like Katja’s design and would suggest proposing it to the general contractor if you like it yourself.
Besides that, I’m a strong advocate of controlled mechanical ventilation with heat recovery. We have gas plus controlled ventilation ourselves. No solar, which from an economic perspective is the next weak point...
We have a demand of about 9 kWh per day for hot water. That’s roughly €200 per year at €0.06/kWh. With a solar system, I save two-thirds of the preheating costs, so around €150. Considering the system costs start at around €4000, anyone can calculate how long it takes to break even.
Even if I assume a heat demand of 15 kWh per day (there are only two of us), it still takes over 20 years for it to pay off.
If this complies with the energy-saving regulations (energy performance regulations / building codes), I would insist on gas plus controlled mechanical ventilation.
Without solar, it’s also a plus that you can skip the buffer tank, which is not the worst thing considering your space constraints.
Thank you for the information. I actually don’t think the floor plan is bad; I already asked my wife about it yesterday, but she had some objections. I’ll need to discuss it with her in more detail.
We definitely need to submit a revision to the authorities, right? The window in the guest bathroom would be located somewhere else then... The foundation slab hasn’t been poured yet; they should start excavating today.
According to the energy saving regulations, gas plus controlled ventilation without solar is allowed—that’s how the whole plan was designed! (However, we don’t yet know how much we will save by leaving out the solar system.)
We definitely need to submit a revision to the authorities, right? The window in the guest bathroom would be located somewhere else then... The foundation slab hasn’t been poured yet; they should start excavating today.
According to the energy saving regulations, gas plus controlled ventilation without solar is allowed—that’s how the whole plan was designed! (However, we don’t yet know how much we will save by leaving out the solar system.)
Well, a mechanical ventilation system with heat recovery is economically just as bad. You spend $10,000 to have good air quality but can achieve the same with a simple exhaust fan and a regular air vent for about $1,200. The latter costs only around $25 more per year in gas but uses significantly less electricity, since mechanical ventilation systems are electrically powered while regular air vents operate purely mechanically. Unfortunately, energy-saving regulations force us to live in airtight buildings and then upgrade them with some inefficient eco-technology that never pays off. Whether it’s mechanical ventilation with heat recovery or solar... it just doesn’t add up.
M4rvin schrieb:
The guest bathroom window would then be located elsewhere... My first concern would be the water supply and drainage lines, which would need to be routed through the slab foundation. If excavation is already underway, that could be tight. What about Yvonne’s suggestion regarding the mounting?Similar topics