Our construction supervisor (BU) is very honest, and we, as well as others, trust him a lot.
However, he is not a fan of ventilation systems.
Here are the prices he quoted. Are there
1. Solutions that are more integrated into the wall or similar, to avoid additional height increases, and
2. Is the price reasonable?
Total area is 187 sqm (2013 sq ft), including about 40 sqm (430 sq ft) of an extension. The rest is spread over two levels in a town villa style.
There is a ceiling opening of about 9 sqm (97 sq ft) to the first floor, which is not included in the 187 sqm (2013 sq ft).
Attached is the text from the BU.
Pluggit Avent fresh air unit with heat recovery included.
Aluminum cross counterflow heat exchanger
Including air ducts, supply and exhaust air outlets, silencers, distributor, cover grilles in standard white plastic, supply and install 14,192.58 €
Blower door test mandatory when installing ventilation system 476.00 €
Increase of total floor construction height from 14 cm (5.5 inches) to 18 cm (7 inches) on the upper floor
By adding 3 cm (1.2 inches) more styrofoam insulation 2,988.97 €
Enthalpy exchanger and summer bypass
No costs yet
However, he is not a fan of ventilation systems.
Here are the prices he quoted. Are there
1. Solutions that are more integrated into the wall or similar, to avoid additional height increases, and
2. Is the price reasonable?
Total area is 187 sqm (2013 sq ft), including about 40 sqm (430 sq ft) of an extension. The rest is spread over two levels in a town villa style.
There is a ceiling opening of about 9 sqm (97 sq ft) to the first floor, which is not included in the 187 sqm (2013 sq ft).
Attached is the text from the BU.
Pluggit Avent fresh air unit with heat recovery included.
Aluminum cross counterflow heat exchanger
Including air ducts, supply and exhaust air outlets, silencers, distributor, cover grilles in standard white plastic, supply and install 14,192.58 €
Blower door test mandatory when installing ventilation system 476.00 €
Increase of total floor construction height from 14 cm (5.5 inches) to 18 cm (7 inches) on the upper floor
By adding 3 cm (1.2 inches) more styrofoam insulation 2,988.97 €
Enthalpy exchanger and summer bypass
No costs yet
R
Radfahrer18 Dec 2023 16:16i_b_n_a_n schrieb:
A mechanical ventilation system with heat recovery is, in my opinion, almost never cost-effective (did anyone claim otherwise?)Here, at least, an annual saving of €387 is mentioned for an investment of €6000.Malle Zwabber schrieb:
My energy consultant calculated my energy consumption with and without a mechanical ventilation system with heat recovery.
All in all, such a system is generally not economically worthwhile. With a living area of 144 m² (1550 sq ft) in my case, the annual savings amount to just €430 minus €43 electricity costs for the ventilation system. So only about €387 per year.W
WilderSueden18 Dec 2023 16:35The energy consultant must have made a mistake. €430 already almost covers the heating bill for a new build of this size.
However, the calculation is not that complicated. To heat 1 cubic meter of air by 1 degree, it requires 0.33 Wh. So, let's calculate for his house with 144 sqm (1550 sq ft) and assume the rooms are 2.5 m (8 ft) high everywhere. We also assume an indoor temperature of 20°C (68°F) and an outdoor temperature of 0°C (32°F). This results in about 2.4 kWh of heat loss per air exchange. Taking ventilation seriously—since the ventilation was only omitted for cost reasons, not because we want to sit in stale air—five air exchanges per day mean approximately 12 kWh of heat loss or 3 to 4 kWh of electricity consumption.
Of course, this calculation is not exact. There is furniture inside, and the ceiling heights might be higher or lower. One ventilation session is also not exactly one full air exchange, and temperatures outside can be above or below 0°C (32°F), while inside it's not always exactly 20°C (68°F). But the order of magnitude is closer to about one-third of the amount stated.
However, the calculation is not that complicated. To heat 1 cubic meter of air by 1 degree, it requires 0.33 Wh. So, let's calculate for his house with 144 sqm (1550 sq ft) and assume the rooms are 2.5 m (8 ft) high everywhere. We also assume an indoor temperature of 20°C (68°F) and an outdoor temperature of 0°C (32°F). This results in about 2.4 kWh of heat loss per air exchange. Taking ventilation seriously—since the ventilation was only omitted for cost reasons, not because we want to sit in stale air—five air exchanges per day mean approximately 12 kWh of heat loss or 3 to 4 kWh of electricity consumption.
Of course, this calculation is not exact. There is furniture inside, and the ceiling heights might be higher or lower. One ventilation session is also not exactly one full air exchange, and temperatures outside can be above or below 0°C (32°F), while inside it's not always exactly 20°C (68°F). But the order of magnitude is closer to about one-third of the amount stated.
M
mariano.dechow18 Dec 2023 20:43Things are really picking up here.
I’m keeping up and reading along carefully.
I don’t have exact information from the builder yet.
But we will go with one and omit the stove and chimney for now, as it seems.
And yes, 20,000 is a lot of money; you have to save elsewhere first and see.
Our interest rate is 3.66%.
I would say we already earn quite well, but the house is definitely NOT a KfW 40 standard; it only complies with the building energy regulations. The exterior wall is 36.5 centimeters (14 inches), and that’s about it.
With controlled ventilation, I feel safer—also because of mold. I got good advice here on that as well.
I’m keeping up and reading along carefully.
I don’t have exact information from the builder yet.
But we will go with one and omit the stove and chimney for now, as it seems.
And yes, 20,000 is a lot of money; you have to save elsewhere first and see.
Our interest rate is 3.66%.
I would say we already earn quite well, but the house is definitely NOT a KfW 40 standard; it only complies with the building energy regulations. The exterior wall is 36.5 centimeters (14 inches), and that’s about it.
With controlled ventilation, I feel safer—also because of mold. I got good advice here on that as well.
Similar topics