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!!!
S
Sebastian7926 Feb 2016 13:59A central system doesn’t need to be controlled – it runs automatically. When properly set up, you won’t hear it, and of course, it doesn’t let in any outside noise.
Of course, there are situations where you want it to run at a higher setting – that’s why we installed the control button in every bathroom and kitchen.
And honestly, was it just because your wife didn’t want visible pipes? I would have had a few words about that.
Of course, there are situations where you want it to run at a higher setting – that’s why we installed the control button in every bathroom and kitchen.
And honestly, was it just because your wife didn’t want visible pipes? I would have had a few words about that.
If a decentralized system is well designed, you don’t need to control it. In living areas, it runs constantly, and you can only switch to a higher setting when needed. In bathrooms, there is an interval operation (every 2 or 4 hours) as well as a push button with a 15 or 30-minute delay.
A central system across three floors was too expensive for us, and there is also no long-term experience regarding deposits or contamination in the pipe systems.
A central system across three floors was too expensive for us, and there is also no long-term experience regarding deposits or contamination in the pipe systems.
S
Sebastian7926 Feb 2016 14:13Of course, there is long-term experience – just Google it. When installed correctly, after 10 years you won’t even find anything in the pipes.
And of course, there are cleaning kits that can be pulled through the pipes.
Expensive is relative – how much does a decentralized system for three floors including core drilling (!!) cost? What is the total power consumption of the fans, or what is the average power draw?
And of course, there are cleaning kits that can be pulled through the pipes.
Expensive is relative – how much does a decentralized system for three floors including core drilling (!!) cost? What is the total power consumption of the fans, or what is the average power draw?
Power consumption is the same as with central systems – I had checked and calculated that once. If I could build again, I would definitely reconsider it – but as I said, I don’t think it’s that bad now. I also assume that there is still some construction moisture in the house at the beginning and that the normal indoor climate has not yet been reached. Maybe one or two will be sufficient permanently.
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