For exhaust devices - where to take the supply air from?

We want to ventilate three rooms in our new building, have a chimney and an exhaust hood with exhaust air, and are unsure where the fresh air can come from. It is a Kfw 70 house:

1) internal guest bathroom in the basement: Since the bathroom has no light well, we want to install an exhaust unit here, which is ventilated through the light well in the adjacent room.

2) utility room on the ground floor: Actually, we want a unit with supply and exhaust air including heat recovery here. However, the outer wall is the entrance area of the house, so for aesthetic reasons we do not want a unit on the outside here. Is there such a device that can be installed, for example, in the upper floor and brings the supply and exhaust air into the room via ducts?

3) bathroom on the upper floor: Here we will have a normal unit with supply and exhaust air including heat recovery installed.

Who else has installed exhaust units - where do you get the supply air from? How can the problem in the utility room be solved?

Thanks for help and ideas!

Is the house already built or is it still being planned?

Hi,

google Blumartin. They manufacture decentralized ventilation units that can also supply air to other rooms via ducts. It's basically a hybrid between a central and a decentralized solution.
Or you could reconsider a complete, central ventilation system. Without a floor plan it's hard to judge, but if you otherwise need X units and wall penetrations, it might not be more expensive after all.

Best regards,

Andreas

Is the house already built or is it still being planned?

The shell construction has started - the basement is almost finished.

Hi,

google Blumartin. They manufacture decentralized ventilation units that can supply air to other rooms through ducts. It is basically a hybrid between a central and decentralized solution.
Or you might reconsider a complete, central ventilation system. It is hard to judge without a floor plan, but if you otherwise need X devices and wall openings, that might not be more expensive.

Best regards,

Andreas

Hello Andreas,
Thanks for the tip. Looks very interesting!!

Best regards
Karen

Hi,

oups....

The shell has started - the basement is almost finished.

to put it mildly, it's a bit late to be worrying about such things now. You will only manage a suboptimal solution at higher costs.

Good luck!

Best regards,

Andreas