Hello everyone,
We are currently starting to deal with the technical aspects of our single-family home.
I haven’t found a thread discussing whether a ventilation system generally makes sense or not. So here is a general discussion thread on the topic:
At first, we looked into various timber frame construction providers, which made us quite sensitive in this area. Naturally, a ventilation system is quite important due to the tighter building envelope, which I can completely understand. However, everything is also marketed accordingly...
Since we have now decided to go with a regional solid construction company, completely different questions arise:
I currently have a detailed offer from a solid construction company:
- $10,000 additional cost for thermal insulation measures
- $13,000 additional cost for a central ventilation system or $9,000 additional cost for a decentralized ventilation system
--> So the repayment subsidy of $18,000 is of little use to me; on the contrary, I am even paying extra for this (of course, I get a “better” house in return).
Key Data:
- Single-family home city villa, 150m² (1,615 ft²) with basement
- Air-to-water heat pump
- Building material: brick
The questions I am now asking myself:
1. Is a ventilation system even necessary to achieve KfW 55 standard?
2. If yes, would it maybe make more sense to go for KfW 70 and forget about the subsidy?
3. Is a ventilation system really that great? There are many reports about noise, high maintenance, etc.
4. If yes, in our building project would a decentralized or central system be better? I have read a lot of positive things about decentralized systems, so central ones might not be an option? Is that correct or not?
5. Is it even possible to reach KfW 55 standard otherwise? Do you really have to ventilate every 2 hours? Are there any experiences?
6. Is the additional $10,000 cost for KfW 55 without a ventilation system justified? Are the prices for the ventilation systems justified?
I know this is an endless debate and there are clearly two opinions here. However, we find it really difficult to make a decision. Maybe a few discussions and information here will help us make up our minds.
We are currently starting to deal with the technical aspects of our single-family home.
I haven’t found a thread discussing whether a ventilation system generally makes sense or not. So here is a general discussion thread on the topic:
At first, we looked into various timber frame construction providers, which made us quite sensitive in this area. Naturally, a ventilation system is quite important due to the tighter building envelope, which I can completely understand. However, everything is also marketed accordingly...
Since we have now decided to go with a regional solid construction company, completely different questions arise:
I currently have a detailed offer from a solid construction company:
- $10,000 additional cost for thermal insulation measures
- $13,000 additional cost for a central ventilation system or $9,000 additional cost for a decentralized ventilation system
--> So the repayment subsidy of $18,000 is of little use to me; on the contrary, I am even paying extra for this (of course, I get a “better” house in return).
Key Data:
- Single-family home city villa, 150m² (1,615 ft²) with basement
- Air-to-water heat pump
- Building material: brick
The questions I am now asking myself:
1. Is a ventilation system even necessary to achieve KfW 55 standard?
2. If yes, would it maybe make more sense to go for KfW 70 and forget about the subsidy?
3. Is a ventilation system really that great? There are many reports about noise, high maintenance, etc.
4. If yes, in our building project would a decentralized or central system be better? I have read a lot of positive things about decentralized systems, so central ones might not be an option? Is that correct or not?
5. Is it even possible to reach KfW 55 standard otherwise? Do you really have to ventilate every 2 hours? Are there any experiences?
6. Is the additional $10,000 cost for KfW 55 without a ventilation system justified? Are the prices for the ventilation systems justified?
I know this is an endless debate and there are clearly two opinions here. However, we find it really difficult to make a decision. Maybe a few discussions and information here will help us make up our minds.
I just spoke with the energy consultant of our general contractor: they do not have any energy-efficient ventilation systems in their portfolio. Maybe one of the subcontractors?
Called a plumber/installer, no knowledge, needs to find out more.
Called the sales manager from Helios: no experience with this, needs to check.
Called a plumber/installer, no knowledge, needs to find out more.
Called the sales manager from Helios: no experience with this, needs to check.
Abzug86 schrieb:
Call to the sales manager at Helios: no experience with that, needs to get informed first.Everything is very well explained at Zehnder, actually. They even offer a subsidy assistance service.S
Strahleman26 Jun 2020 15:08Abzug86 schrieb:
I just spoke with the energy consultant from our general contractor: they don’t have any eligible ventilation systems in their portfolio. Maybe one of the subcontractors? Any central ventilation system is eligible for funding, as long as the heat pump and ventilation system can be controlled together. According to BAFA, even a simple smart home solution is sufficient for this. It’s not like with heat pumps, where there is a specific list of eligible systems. Your energy consultant probably doesn’t understand the funding rules. Can you exclude subcontractors and contract the work yourself? It might be worth considering, especially if not even the installer is aware of the funding.
There are no subsidies, whatever is being claimed is really nonsense. You get your KFW55 subsidy and that's it. It may be that there are regional programs in the federal states, but I don’t know. An air-to-water heat pump almost never meets the subsidy criteria. A central controlled residential ventilation system is not subsidized.
S
Strahleman26 Jun 2020 16:28Bookstar schrieb:
There are no subsidies; what is often claimed is absolutely nonsense.You should better inform yourself. If you have an eligible heat pump, then a jointly controlled mechanical ventilation system with heat recovery is also eligible for funding. This is explicitly stated in the BAFA information sheet on eligible costs – Heating with Renewable Energies (status 26.03.2020) on pages 4/5:"Specifically, the typical cost items listed below, which are not exhaustive, are eligible.
Heat pump systems combined with ventilation units including heat recovery
- provided that eligible heat pumps are combined with ventilation units including heat recovery and these components are operated with joint controls
- including necessary ventilation ducts and ventilation accessories"
As mentioned, this applies only if the heat pump itself is eligible for BAFA funding (annual performance factor >4.5).