ᐅ Mechanical ventilation with heat recovery—is it really necessary? Looking for advice, please.
Created on: 12 Nov 2012 10:02
L
laieI’ve been looking around for hours and I’m still at the beginning! But I’ll start from the beginning: We’re planning a new build, 155 sqm (1,670 sq ft), KfW 70 standard, air-to-water heat pump, and a fireplace for the cold days. Four people… (anything missing?)
So far, we always thought that a ventilation system was a MUST. We’ve requested several quotes and ventilation was always included. Our newest architect (one who finally convinced us!) suggested a controlled mechanical ventilation system with heat recovery in his calculations. However, he made it very clear that it’s NOT mandatory if you ventilate properly. Cost: €10,000 (around $11,000)! We heard that for the first time… (embarrassed)
For us, €10,000 (around $11,000) is a lot of money! We haven’t been great at ventilation so far, especially in winter. But we never had mold (probably because of the 100-year-old house).
Can anyone help or give advice on how to reach the right decision? Who assists with such questions… an energy consultant?
Are there other systems or types of ventilation that are more affordable but still make sense?
Thank you very much!
So far, we always thought that a ventilation system was a MUST. We’ve requested several quotes and ventilation was always included. Our newest architect (one who finally convinced us!) suggested a controlled mechanical ventilation system with heat recovery in his calculations. However, he made it very clear that it’s NOT mandatory if you ventilate properly. Cost: €10,000 (around $11,000)! We heard that for the first time… (embarrassed)
For us, €10,000 (around $11,000) is a lot of money! We haven’t been great at ventilation so far, especially in winter. But we never had mold (probably because of the 100-year-old house).
Can anyone help or give advice on how to reach the right decision? Who assists with such questions… an energy consultant?
Are there other systems or types of ventilation that are more affordable but still make sense?
Thank you very much!
B
Bauexperte12 Nov 2012 13:25Hello,
You are building to KfW 70 standard – I know only a few architects who design monolithic structures, so yours will probably have an external thermal insulation composite system (ETICS / external wall insulation). The valid energy saving regulation – simply put – demands that the final building envelope performs like a "thermal flask." So, if you indeed install ETICS and cannot ventilate properly – especially if you and your wife both work outside the home – that means ventilating thoroughly at least four times a day for about 10 minutes each, a mechanical ventilation system remains a strong recommendation. Perhaps the other providers suggested this system for that reason?
Try, for example, to find a suitable expert through the Association of Independent Surveyors (or equivalent), someone whose profile clearly states that they have proper training in energy consulting and not just attended a questionable seminar. Otherwise, call me if you get stuck.
This is really a dilemma nowadays – neither sellers nor architects seem capable of selling a price, it must be really difficult to advise well with arguments and facts.
Kind regards
Laie schrieb:A mechanical ventilation system with heat recovery is indeed not mandatory; whether it is wise to skip it is a completely different question!
We are planning a new build, 155sqm (1670 sq ft), KfW 70 standard, air-to-water heat pump and fireplace for the cold days. 4 people...(anything missing)
... Our latest architect (one who finally convinced us!) suggested a mechanical ventilation system with heat recovery in his calculation. But he made it very clear, NOT A MUST! If you ventilate properly. Cost: €10,000! This was the first time we heard this...(embarrassed)
You are building to KfW 70 standard – I know only a few architects who design monolithic structures, so yours will probably have an external thermal insulation composite system (ETICS / external wall insulation). The valid energy saving regulation – simply put – demands that the final building envelope performs like a "thermal flask." So, if you indeed install ETICS and cannot ventilate properly – especially if you and your wife both work outside the home – that means ventilating thoroughly at least four times a day for about 10 minutes each, a mechanical ventilation system remains a strong recommendation. Perhaps the other providers suggested this system for that reason?
Laie schrieb:That’s a lot of money for everyone! If you read around in this forum a bit, you’ll find that many homeowners who installed a mechanical ventilation system with heat recovery wouldn’t want to miss it anymore.
€10,000 is a lot of money for us! We have not been good ventilators/occupants so far, especially in winter. But we have never had mold (probably due to the 100-year-old house).
Laie schrieb:€uro would probably agree – but I am not that confident, since many so-called energy consultants leave much to be desired, and I have dealt with quite a few I wished I could kick in the behind. Very few really know their stuff and often recommend nonsense that makes me sick.
Can anyone help or give tips on how to reach the right decision? Who helps with such questions... energy consultant?
Try, for example, to find a suitable expert through the Association of Independent Surveyors (or equivalent), someone whose profile clearly states that they have proper training in energy consulting and not just attended a questionable seminar. Otherwise, call me if you get stuck.
Laie schrieb:I assume your architect is pretty good? Didn’t he at least advise you to consider a decentralized system if money is tight? Or do you only think he’s good because he apparently saves you €10,000?
Are there other systems or ventilation types that are cheaper but still make sense?
This is really a dilemma nowadays – neither sellers nor architects seem capable of selling a price, it must be really difficult to advise well with arguments and facts.
Kind regards
You are building to KfW 70 standard – I only know a few architects who plan with monolithic construction, so yours will likely have an external thermal insulation composite system (ETICS). The current energy saving regulations – simply put – require the final building to behave like a “thermos flask.” So if you actually install ETICS and you and your wife are both working and cannot ventilate properly (at least four times a day for about 10 minutes each), then a mechanical ventilation system with heat recovery is still a good recommendation.Do you see significant differences regarding mechanical ventilation between an ETICS and a monolithic wall construction?
Both should be airtight… right?
You are building KfW 70 standard – I know only a few architects who design solid masonry construction, so your architect likely planned an external thermal insulation composite system (ETICS / external wall insulation). The current energy saving regulations – to put it simply – require the final building to be like a "thermos flask." So if ETICS is actually installed and you and your wife – assuming you both work – cannot ventilate properly (at least 4 times a day for about 10 minutes each), a mechanical ventilation system with heat recovery is and remains a good recommendation. Maybe that’s why the other providers offered this system?
=>All providers offered a system, but until now it was "included" or sold together with the heat pump. What exactly does ETICS mean? So far, I don’t know who stays home all day and can ventilate to that extent, which is why I’m also currently in favor of a mechanical ventilation system with heat recovery.
That is a lot of money for anyone! But if you read through this forum a bit, you will realize that quite a few builders would not want to do without a mechanical ventilation system with heat recovery once it is installed.
=>True!
€uro would probably agree – I’m not so optimistic because many who call themselves energy consultants would deserve criticism, and I have had to put up with some who I would have liked to kick in the butt. Very few actually know what they’re doing and recommend such nonsense to their clients that makes me sick.
=>I’ve noticed that too, so that makes me uncertain.
For example, find a suitable expert through the Association of Independent Experts who also states in their biography that they have professional training in energy consulting and have not just attended a questionable seminar. Otherwise, call me if you get stuck.
I assume your architect is good? Didn’t he advise you at least to consider a decentralized system if budget is the issue? Or do you only think he’s good because he apparently saves you around €10,000?
=>We only had two meetings with him so far. We’re still at the start and I want to prepare for the next meeting. We like him because he designed a great house, the costs seem transparent, and we like him personally. The rest remains to be seen! Most providers failed after the second meeting. The matter of saving €10,000 is an interesting point – maybe he told us that to keep within budget???
It’s currently a real dilemma – neither salesmen nor architects are able to sell prices… it must be really difficult to advise with arguments and facts.
=>To me, everyone is a salesman…I can’t stand this type of person and avoid them. Our current guy seems not to be like that… but the “saving money” part makes me uncertain again.
Best regards
=>All providers offered a system, but until now it was "included" or sold together with the heat pump. What exactly does ETICS mean? So far, I don’t know who stays home all day and can ventilate to that extent, which is why I’m also currently in favor of a mechanical ventilation system with heat recovery.
That is a lot of money for anyone! But if you read through this forum a bit, you will realize that quite a few builders would not want to do without a mechanical ventilation system with heat recovery once it is installed.
=>True!
€uro would probably agree – I’m not so optimistic because many who call themselves energy consultants would deserve criticism, and I have had to put up with some who I would have liked to kick in the butt. Very few actually know what they’re doing and recommend such nonsense to their clients that makes me sick.
=>I’ve noticed that too, so that makes me uncertain.
For example, find a suitable expert through the Association of Independent Experts who also states in their biography that they have professional training in energy consulting and have not just attended a questionable seminar. Otherwise, call me if you get stuck.
I assume your architect is good? Didn’t he advise you at least to consider a decentralized system if budget is the issue? Or do you only think he’s good because he apparently saves you around €10,000?
=>We only had two meetings with him so far. We’re still at the start and I want to prepare for the next meeting. We like him because he designed a great house, the costs seem transparent, and we like him personally. The rest remains to be seen! Most providers failed after the second meeting. The matter of saving €10,000 is an interesting point – maybe he told us that to keep within budget???
It’s currently a real dilemma – neither salesmen nor architects are able to sell prices… it must be really difficult to advise with arguments and facts.
=>To me, everyone is a salesman…I can’t stand this type of person and avoid them. Our current guy seems not to be like that… but the “saving money” part makes me uncertain again.
Best regards
My name is Laie!... and what is monolithic construction? I also don’t know what WDVS is. I could just quote from the services section of this brochure:
"...Exterior masonry as a plastered facade with a 'thermal system,' including thermal insulation and textured finish... Inner leaf of the exterior masonry made of 17.5 cm (7 inches) high-insulation aerated concrete blocks (Ytong)..."
We have also talked about other things; so far, we have just been getting to know each other. At the next appointment, we can clarify any questions...
"...Exterior masonry as a plastered facade with a 'thermal system,' including thermal insulation and textured finish... Inner leaf of the exterior masonry made of 17.5 cm (7 inches) high-insulation aerated concrete blocks (Ytong)..."
We have also talked about other things; so far, we have just been getting to know each other. At the next appointment, we can clarify any questions...
B
Bauexperte12 Nov 2012 15:33Hello,
Kind regards
Laie schrieb:WDVS => External Thermal Insulation Composite System (ETICS)
=>All suppliers have offered a system, but so far it was included or sold together with the heat pump. What does WDVS mean? So far, I’m not sure who is at home all day and can ventilate to that extent, so I am currently in favor of controlled residential ventilation.
Laie schrieb:What is his initial rough calculation?
We like him because he designed a great house and the costs seem transparent...
Laie schrieb:I’m also a salesperson—heart and soul.
=>For me, all sellers are the same—I can’t stand this kind of people and avoid them.
Laie schrieb:Maybe software, definitely not the name itself, or are you posting under someone else’s account?
My name is Laie!...
Laie schrieb:So, with ETICS.
"...Exterior masonry as a plaster façade with a 'thermal system', including thermal insulation, textured plaster, inner leaf of the exterior masonry made of 17.5 cm (7 inches) high-insulation aerated concrete blocks (Ytong)."
Kind regards
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