Ventilation and exhaust: Hygienic problems after 5-6 years

Is the additional insulation and/or heating of the ventilation pipes included in the plan? Or will the attic be converted right away?

Attic uninhabitable but insulated, pipes also insulated - the floor itself remains unheated.

Yes, there are different systems, although I also do not count the simple exhaust system with window rebate ventilators as ventilation systems...

1. Simple exhaust system:


2. Decentralized ventilation system without heat recovery



3. Decentralized system with heat recovery



1. Central ventilation system with heat recovery (without heat recovery just imagine the heat exchanger removed)

However, the principle of the decentralized system with heat recovery shown here does not work exactly like that. The fan takes over the supply of fresh and exhaust air by changing its rotation direction after time X. But two fans must always operate in parallel. One brings in fresh air (e.g., in the bedroom) and the other exhausts air (e.g., in the children's room). Therefore, an (imperceptible) airflow throughout the entire house is achieved. You can also do the combination 2 to 1. In large rooms, like the living room, it makes sense to place two fans directly. This also works across floors.

However, the moisture rooms (kitchen, bathroom, utility room) are excluded here. One wants to remove odors and moisture from the room and not distribute them throughout the house. Therefore, only exhaust fans (which are also cheaper to purchase) are used here, which are moisture- and time-controlled (meaning: you set at which humidity the fan turns on and how long it runs afterwards). In addition, these exhaust fans should also be manually controllable – after using the toilet, humidity usually does not increase. Then you start the exhaust fan manually.

Since I am installing the system myself, I have to watch my fingers

I don't see why the system should fail...

Because if unheated and insufficiently insulated... then condensation forms on the outside of the pipes, which usually finds its way into the house or causes damage to the roof, etc...

Simple physics...



It is a simple principle sketch to show people who are not familiar what is being talked about.

That there are a million variants, with a fan here, a fan there, is a topic especially for decentralized systems in single-family homes, mixed solutions are also possible... but that does not mean your solution is the best and right one... it always depends on many different factors which system is installed and how many fans are needed...

Well, as previously mentioned: The attic will be fully insulated and the pipes will also be insulated - so I do not expect any problems there.

Why should condensation form on the outside of the pipes? The air inside the pipes is warmer than the attic, except for the 1m section through the roof (except for a few weeks in summer, but even then the difference is not big enough because a lot of water "goes into the air" due to the general warmth). Simple physics. And that 1m just has to be insulated properly.