Planning / Design of a Controlled Residential Ventilation System - Maximum Pipe Lengths

Hello everyone,

maybe I don’t have to ask this question in the Telekom-colored forum (and register there as well...).

We are currently planning the (core) renovation of a 60s house, and the installation of a controlled residential ventilation system is also under discussion. While the overall planning is being done by an architect, the controlled residential ventilation issue has proven to be somewhat more difficult. The HVAC company lets the controlled residential ventilation planning be done by a wholesaler (it’s about a Pichler LG350), and there are communication problems there (openings lead to the townhouse neighbor, etc.).

Before we now either ditch the company or the controlled residential ventilation (or just let the HVAC guys do heating/sanitary), I wanted to clarify a fundamental point here:

- in the "ventilation plan" (created with a variant of an airPLAN software, which apparently circulates in various freeware versions) it says: Maximum length between distributor and cup valve: 15m

Question: Does anyone know if that is correct? Is that completely device-independent? The number also appeared in my "test draft," which I made with the above-mentioned program completely without devices)

With the possibly "old building compliant" installation in the attic (and corresponding piping), we would definitely exceed the 15m pipe length.

We are currently rather at the point of giving up on the system and ventilating minimally decentralized (aka "functional rooms")...

Christoph

Is this a single-family house that you want to renovate? What are its dimensions? Do you want to put the controlled residential ventilation in the basement? I ask because normally it should fit within 15 meters in a "normal" single-family house?! I don't know if there are actually length limits.

This is an end-terrace house in a downtown location, with a basement, ground floor, first floor, and attic (~200m²).

It must be said: Controlled residential ventilation is not a must-have for us – we see the comfort gain and probably also the contribution to moisture regulation, but it doesn't have to be done at all costs.

The energy consultant's first plan with installation in the basement and routing the pipes along the exterior wall (under the insulation) is not considered very appealing by the manufacturer (and the costs were relatively high or the installer did not really want to commit due to the extensive chipping work...).

In the discussion, we then came to the option of placing the system itself in the attic and distributing the lines from there. However, the lines would then have to be distributed not only vertically (attic -> ground floor ~ 5.3m) but also horizontally along the walls (at least ~15m).

Does actually one pipe run from the central unit to each outlet separately? So number of pipes == number of ceiling vents?

Attached is the aforementioned "duct plan".

But the lines would then have to be distributed not only vertically (attic -> ground floor ~ 5.3m), but

Is there a flaw in your thinking? Place the unit in the middle of the distribution board. To the ceiling of the ground floor, you need 5.3 meters. If the single-family house were 12 meters long, you would need roughly another 6 meters, then you would even be at the short exterior wall. But you don’t have to, because it is enough if the valve is located in the interior wall. With a room width of 3 meters, you therefore need a maximum of 8/9 meters for the longest distance.

Oh, my attic would now be your inhabited top floor. That is my misconception. Still, everything should work with <= 15 meters.

I recognize another misconception of mine: you don't have a shaft to lay the pipes :(

No, the attic is converted, i.e. positioning in the middle and/or arbitrary distribution is unfortunately not possible. Since it is otherwise an old building, we try to stick as closely as possible to the installation shafts (for the attic->ground floor path) and drillings at the "corners".

EDIT: although if I were to run the cables along a shaft under the roof, I might possibly come closer to your values. Wait a moment, I'll put something in..