Fans

There are heating and ventilation companies that offer a 10-year warranty... if you take out a maintenance contract. You always have 2 years warranty / guarantee of course.

So if everyone is on vacation, where is the moisture supposed to come from??? Once the building is properly dry after the construction phase, the moisture mostly comes from the occupants... Unless you have damp walls but that is a different problem.

I’m not sure if the operating costs are just laughable.
After all, the ducts of a controlled residential ventilation system also need to be cleaned, right?
I read in a report that a controlled residential ventilation system that is not properly maintained can become a veritable breeding ground for germs.
Filters also need to be replaced quite frequently.
I do think that 200 - 300 € per year can quickly add up. Without electricity!

Best regards, Frank

Here is a brief remark from me.
Before our consultation in Berlin, I had a long phone call with someone who has a controlled residential ventilation system. She told me in response to my question about maintenance/cleaning of the pipes that her husband changes the filters and that after years of operating the controlled residential ventilation system, they hardly noticed any contamination in the air intake ducts (she apparently once reached in there and found nothing inside). So she doesn’t see any reason to commission a company for cleaning.

Since this contradicted the information I had read so far, I asked again at the Lüftungsbüro Berlin. There I was confirmed that the owner of the controlled residential ventilation system can change the filters themselves and the intake pipes are usually clean (no idea — I assume that in a controlled residential ventilation system the filters are located directly at the intake nozzle). However, normal household dust (consequently the beloved dust bunnies ) would over time dirty the exhaust ducts. These can apparently only be cleaned by a company. = maintenance costs

Does anyone here who has had a controlled residential ventilation system for a longer time have ever checked the exhaust ducts and can confirm / relativize this statement or completely refute it?

You keep finding contradictory information on this topic. On the one hand, the information from controlled residential ventilation supporters (who usually have one), and on the other hand, from controlled residential ventilation opponents. Personally, I find it very difficult to filter out the correct information on this. I have come to the conviction that ventilation is sensible for me, but after weighing the information available to me, I decided on the decentralized variant.

@f-pNo

That's exactly how I see it too... if then decentralized without all the channels.
If a system extracts the humidity from the rooms, then the moisture can also condense and precipitate in the channels if the system is, for example, located in a cooler room... . Then mold might develop in the channels and not on the wall.

@f-pNo

That's exactly how I see it too... if then decentralized without all the channels.
If a system extracts the humidity from the rooms, then the moisture can also condense and precipitate in the channels, for example, if the system is located in a cooler room... . Then mold possibly grows in the channels and not on the wall.

If there is mold in the channels, controlled residential ventilation is your smallest problem.
The device itself has a condensate drain.

@f-pNo

I see it exactly the same way... if then decentral without all the channels.
If a system extracts the humidity from the rooms, then the moisture can also condense and precipitate in the ducts, for example if the system is located in a cooler room... . Then mold may develop in the ducts and not on the wall.

Controlled residential ventilation and piping belong within the heated envelope. Then nothing condenses there. Condensation occurs at most in the heat exchanger, and it is designed for that...

No, it cannot, since the controlled residential ventilation should be located within the building envelope (otherwise this is a construction defect)... and since the dew point cannot be undershot, no moisture occurs in the pipes... only at the heat exchanger...

And anyone who is afraid of the horrendous operating costs has no idea what the inside of a ventilation unit looks like and what kind of costs arise...

Here is an example of the operating costs:

Electricity = between 20 and 150 watts depending on the air volume, so about 50W on average (since the systems rarely run at full load) ergo about 100 euros per year with almost continuous operation, i.e. 24h/365 days

Filter: 1 sqm F6 filter is available everywhere (ventilation companies, sanitary suppliers, filter manufacturers) for about 30 euros... the quantity is sufficient depending on the ventilation unit for 5-6 years, so about 5 euros per year for filters... let’s say 10 if you also install filters in the valve plates etc.

Cleaning of the ducts (is necessary with regular filter changes, about every 10 years) about 500 euros for a "normal" single-family house

so you end up with operating costs of about 160 euros per year... so definitely cheaper than a renovation due to mold infestation etc. because of insufficient ventilation...

Decentralized systems should only be installed in apartment buildings or during modernizations... why opt for a half solution when the finished product is available...