ᐅ Decentralized Mechanical Ventilation – Yes or No? Pros and Cons?
Created on: 26 Feb 2016 13:15
N
nils1985
Dear Forum,
We are currently planning our new build, and I have now received the scope of work from our builder. First of all: one thing is certain, a central heat recovery ventilation system is out of the question because it is too expensive.
The basic data for our single-family house:
130 sqm (1,400 sq ft), underfloor heating on the ground floor and in the bathroom (upper floor), radiators everywhere else, all windows with roller shutters (thermally insulated roller shutter boxes with half-shells).
[U]According to our scope of work, the following is to be installed:[/U]
"Decentralized ventilation system Lunos e² with heat recovery (up to 90%), very low power consumption (only 0.09 watts / sqm (0.008 watts / sq ft) thanks to direct current), and a 10-year warranty on the ceramic heat exchanger. Fully integrated into the exterior wall. Exhaust fans as AB 30/60."
[U]Our wall construction is as follows:[/U]
- Double-shell facing masonry – total thickness of 45 cm (18 inches).
- Inner leaf – 17.5 cm (7 inches) thick aerated concrete blocks as plan bricks, WLZ 0.10, compressive strength PP2, brand Ytong.
- 14 cm (5.5 inches) hydrophobic (water-repellent) core insulation boards KDII with staggered joints, WLG 035.
- 2 cm (0.8 inches) air gap.
- 11.5 cm (4.5 inches) facing brick.
- U-value is approx. 0.16 W/m²K.
- Triple-glazed insulating glass as thermal insulation glass (Ug value 0.7 W/m²K).
Is it really necessary to install a heat recovery ventilation system? I know it prevents mold and ensures controlled air exchange. But is it really required? I am rather skeptical about it. I have already been in several houses (built from 2013 onwards) without heat recovery ventilation and haven’t noticed anything negative.
So far, the disadvantages outweigh the benefits for me (just my own opinion):
- Increased energy use (electricity, heat loss).
- Holes in the wall.
- Noise from external influences and the ventilation system itself.
- Energy loss during winter.
- Higher temperatures in the bedrooms during summer.
If we decide to go with a decentralized heat recovery ventilation system, how many fans would be needed? Where would it be advisable to install them?
Thank you in advance for your effort and opinions!!!
We are currently planning our new build, and I have now received the scope of work from our builder. First of all: one thing is certain, a central heat recovery ventilation system is out of the question because it is too expensive.
The basic data for our single-family house:
130 sqm (1,400 sq ft), underfloor heating on the ground floor and in the bathroom (upper floor), radiators everywhere else, all windows with roller shutters (thermally insulated roller shutter boxes with half-shells).
[U]According to our scope of work, the following is to be installed:[/U]
"Decentralized ventilation system Lunos e² with heat recovery (up to 90%), very low power consumption (only 0.09 watts / sqm (0.008 watts / sq ft) thanks to direct current), and a 10-year warranty on the ceramic heat exchanger. Fully integrated into the exterior wall. Exhaust fans as AB 30/60."
[U]Our wall construction is as follows:[/U]
- Double-shell facing masonry – total thickness of 45 cm (18 inches).
- Inner leaf – 17.5 cm (7 inches) thick aerated concrete blocks as plan bricks, WLZ 0.10, compressive strength PP2, brand Ytong.
- 14 cm (5.5 inches) hydrophobic (water-repellent) core insulation boards KDII with staggered joints, WLG 035.
- 2 cm (0.8 inches) air gap.
- 11.5 cm (4.5 inches) facing brick.
- U-value is approx. 0.16 W/m²K.
- Triple-glazed insulating glass as thermal insulation glass (Ug value 0.7 W/m²K).
Is it really necessary to install a heat recovery ventilation system? I know it prevents mold and ensures controlled air exchange. But is it really required? I am rather skeptical about it. I have already been in several houses (built from 2013 onwards) without heat recovery ventilation and haven’t noticed anything negative.
So far, the disadvantages outweigh the benefits for me (just my own opinion):
- Increased energy use (electricity, heat loss).
- Holes in the wall.
- Noise from external influences and the ventilation system itself.
- Energy loss during winter.
- Higher temperatures in the bedrooms during summer.
If we decide to go with a decentralized heat recovery ventilation system, how many fans would be needed? Where would it be advisable to install them?
Thank you in advance for your effort and opinions!!!
B
Bauexperte26 Feb 2016 18:14Mycraft schrieb:
Hmm, Sebastian is right, there is a lot of fear and concern... I once posted pictures of the inside of my system after several years of continuous operation... there wasn’t really much dust on it... There have been quite reliable reports on ventilation systems for some time; however, if a homeowner wants to find them, he or she has to search somewhat thoroughly. Whether central or decentralized, ventilation systems can generate significant profits... the manufacturers are well aware of this and tend to keep fears and concerns "well hidden." At the same time, every manufacturer recommends regular maintenance of ventilation systems; suspicious minds might see a conflict of interest there.
The often praised technical expert Konrad Fischer, as well as websites of companies specializing in the maintenance of small and large ventilation systems both domestically and internationally, offer good information.
Best regards, Bauexperte
We replaced the bathroom exhaust vent at my parents’ house – a 28-year-old terraced house – which was quite unpleasant. But well, you don’t usually have exhaust air mixed with fresh air in the ventilation system like that.
At the time, we also watched some YouTube videos about cleaning services; the ducts weren’t in terrible condition, but they definitely weren’t spotless either.
As I said, if I had to choose again, I would think very carefully about what to do.
At the time, we also watched some YouTube videos about cleaning services; the ducts weren’t in terrible condition, but they definitely weren’t spotless either.
As I said, if I had to choose again, I would think very carefully about what to do.
Was there a filter in the bathroom exhaust? In mechanical ventilation with heat recovery systems, there are filters, and also in the exhaust vents. This keeps the ducts very, very clean. If filters are not changed for 28 years, the decentralized ventilation units are probably quite dirty as well. With a central system, there are fewer filters, so less maintenance is needed, and it is more cost-effective because you can easily cut the ducting material to size, which then lasts for many years.
S
Sebastian7926 Feb 2016 20:36The continuous roll option isn’t available for all demand-controlled ventilation systems – with our Helios it works, but for example Danfoss requires quite expensive filter cartridges.
Just wanted to mention that for fairness.
Just wanted to mention that for fairness.
S
Sebastian7927 Feb 2016 08:04When reading questions about ventilation or building services in general, the type of filters seems to be the last thing a homeowner considers.
By the way, I didn’t pay any attention to that either.
By the way, I didn’t pay any attention to that either.
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