ᐅ Choosing a Mechanical Ventilation with Heat Recovery System Manufacturer – How to Approach?

Hello, I’m Matthias,
I am currently in the final stages of planning (hopefully soon submitting the building permit).
I want to build to the KfW55 standard, which requires a controlled residential ventilation system. But primarily for comfort reasons!
At first, I quickly considered Helios, then Zehnder... shortly after that Komfovent. And so it went on from brand to brand. Since this is a major cost factor, I want to do everything right and take some more time to consider your experiences as well.

What is the best way to proceed? How do I decide on a manufacturer? Where should I start?

Which criteria should I consider besides the following?:
- Operating noise (I am very sensitive)
- KNX integration
- Intelligent, room- and demand-based control (VOC & humidity)
- Cooling/air dehumidification in summer (via earth tubes around the house/basement + heat exchanger in the supply air)
- Good accessibility for cleaning

//Key data\\
160m² (1722 ft²)
2.5 floors
3 bedrooms + 1 bathroom + 1 toilet
Open plan living-dining-kitchen area
Basement
Underfloor heating (gas)

That’s a lot of questions... I didn’t want to scatter this piece by piece. Any constructive advice is welcome.

Whether Helios or Zehnder, both can do it all and more or less equally well. You really can't go wrong with either.

Such a ventilation system is extremely simple. A few fans with a heat exchanger. I can recommend the Erlus ventilation chimney.

ts-mc schrieb:

Hello, I’m Matthias,
I am currently in the final stages of planning (hopefully submitting the building permit/planning permission soon).
I want to build to KfW55 standard and for that, I need a controlled residential ventilation system. But mainly for comfort reasons!
At first, I quickly looked at Helios, then Zehnder... shortly after, Komfovent. And so it went from brand to brand. Since this is a major cost item, I want to do everything right and take some more time to consider your experiences.

What is the best way to proceed? How do I decide on a manufacturer? Where should I start?

What criteria should I consider besides the following?:
- Operating noise (I’m very sensitive)
- KNX integration
- Intelligent room- and demand-based control (VOC & humidity)
- Cooling/air dehumidification in summer (via underground pipe around the house/basement + heat exchanger in supply air)
- Good accessibility for cleaning

//Basic data\\
160m² (1,722 sq ft)
2.5 storeys
3 bedrooms + 1 bathroom + 1 WC
Open living-dining-kitchen area
Basement
Underfloor heating (gas)

That’s a lot of questions... I didn’t want to scatter them piece by piece. Any objective advice is welcome.

Why do you need controlled residential ventilation for KfW55? I’m building a monolithic house with a heat pump (probably ground-source heat pump) and don’t need controlled ventilation. Have you considered switching to an air-water heat pump and adding a photovoltaic system? That might be more efficient than controlled ventilation and gas.

Better choose a competent company that provides proper planning and has experience with the subject.

If you let just anyone install it and even allow them to pick the device for you, it definitely won’t turn out the way you expect.

Additionally, I would recommend “keep it simple.” I also like automation, but in my opinion, there isn’t much meaningful control to be done with a mechanical ventilation system with heat recovery. Most settings (time and weekly schedules) can be programmed once and then it runs automatically.

The added value of integrating it with KNX seems limited to me, especially compared to the usually significant extra costs.

However, I also believe that CO2 or other sensors are not necessary, because in normal use and daily operation of the house, one setting works well. For the couple of parties or other special occasions per year, you can simply adjust it manually.

But of course, there are certainly other opinions on this...