Hello everyone,
we are building a KfW 70 house, which is economic even without a mechanical ventilation system.
Now, like many others, we are uncertain whether we really want to install a mechanical ventilation system. It has been planned, but the prices quoted are quite high... A decentralized system also seems to be similarly expensive due to the number of rooms and additionally causes quite a few holes in the nice facade...
Our heating engineer, who also installs ventilation systems, suggested installing fans in the exterior walls of the wet rooms (guest toilet and bathroom). These would be controlled by a switch and/or humidity sensors to extract the moist air from the rooms.
Additionally, a cooker hood with exhaust ventilation is recommended for the kitchen.
What do you think about this?
From a cost perspective, it does seem to be considerably cheaper.
we are building a KfW 70 house, which is economic even without a mechanical ventilation system.
Now, like many others, we are uncertain whether we really want to install a mechanical ventilation system. It has been planned, but the prices quoted are quite high... A decentralized system also seems to be similarly expensive due to the number of rooms and additionally causes quite a few holes in the nice facade...
Our heating engineer, who also installs ventilation systems, suggested installing fans in the exterior walls of the wet rooms (guest toilet and bathroom). These would be controlled by a switch and/or humidity sensors to extract the moist air from the rooms.
Additionally, a cooker hood with exhaust ventilation is recommended for the kitchen.
What do you think about this?
From a cost perspective, it does seem to be considerably cheaper.
As long as it is clear that everything is fine when the dew point is not crossed... you can easily check where and when moisture condenses using a psychrometric chart.
But what happens if the ventilation system is installed in an unheated basement (15°C / 59°F) or in an uninsulated attic?
Would that be considered a construction defect?
I have personally seen several suppliers install equipment in such locations.
I
But what happens if the ventilation system is installed in an unheated basement (15°C / 59°F) or in an uninsulated attic?
Would that be considered a construction defect?
I have personally seen several suppliers install equipment in such locations.
I
f-pNo schrieb:
Has anyone here who has had a mechanical ventilation system with heat recovery installed for a longer period checked the exhaust ducts and can confirm, qualify, or completely refute the statement that contamination does not occur at the air intake but through household dust, etc., in the exhaust ducts?
Mycraft schrieb:
Cleaning the ducts (necessary with regular filter changes, roughly every 10 years) costs about 500 euros for a standard single-family home.
However, decentralized systems should only be installed in rental buildings or during renovations... why settle for a partial solution when a complete product is available?
Can anyone (perhaps you, @Mycraft) confirm or refute the statement about the contamination of the exhaust ducts? To me, it sounds plausible since (probably) there is no filter upstream of the "air extraction" (in my opinion).
One of the reasons we decided on the decentralized solution is the price. Our decentralized system will cost roughly half (possibly 40%) of a central unit. (In my post on page 2, I exchanged private messages with two members who have a mechanical ventilation system with heat recovery about prices.) It may not be representative, but it gives an indication.
D
DerBjoern3 Dec 2013 15:02fragri schrieb:
It’s clear that as long as the dew point is not fallen below, everything is fine... you can easily check where and when moisture condenses using a psychrometric chart.
But what if the ventilation system is installed in an unheated basement (15°C (59°F)) or in an attic without insulation?
Would this then be considered a defect?
I have seen several suppliers install units in such locations myself.
IYes, that is a defect.
D
DerBjoern3 Dec 2013 15:04DerBjoern schrieb:
Yes, that is a defect. Addition: Unless the system and pipes are properly insulated.
Very interesting, @Mycraft. Thank you.
If I understand correctly, the author installed the system themselves or was primarily responsible for supervising the installation, or at least planned it. They perform the cleaning (except for the overlooked pipe) annually or every two years. Over time, a significant amount does accumulate each year.
Since I don’t have much experience with central systems, are the pipes and components installed by a company in a new build similarly (easily) accessible as in this example? I thought I had read that pipes are often installed inside walls, ceilings, etc. Regardless, companies may not always use simple and straightforward construction methods.
If I understand correctly, the author installed the system themselves or was primarily responsible for supervising the installation, or at least planned it. They perform the cleaning (except for the overlooked pipe) annually or every two years. Over time, a significant amount does accumulate each year.
Since I don’t have much experience with central systems, are the pipes and components installed by a company in a new build similarly (easily) accessible as in this example? I thought I had read that pipes are often installed inside walls, ceilings, etc. Regardless, companies may not always use simple and straightforward construction methods.
No, the pictures show 7 years of continuous operation... the heat exchanger further down has been in use for 14 years... filters are only replaced annually...
The installation of the pipes is a matter of planning... the ventilation company usually doesn’t care how the pipes are routed later on... so as the builder, you should have the pipe layout explained before installation and express any wishes if necessary...
However, I can access nearly everything on my system... for example, two of my exhaust ducts are only about 2m (6.5 feet) long, so cleaning in that area will probably be relatively quick later on...
The installation of the pipes is a matter of planning... the ventilation company usually doesn’t care how the pipes are routed later on... so as the builder, you should have the pipe layout explained before installation and express any wishes if necessary...
However, I can access nearly everything on my system... for example, two of my exhaust ducts are only about 2m (6.5 feet) long, so cleaning in that area will probably be relatively quick later on...
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