DIY ventilation heat exchanger

[Fornax]

Originally Posted by kostas

I also noticed that you haven't installed an outlet duct in the bathroom, I guess it's for the constructing difficulties but extracting the stale air from there will definitely help further more.

At this point in time the bathroom and toilet (kitchen inlet is blocked) are connected to the old whole house exhaust fan in the attic. That one will be decommisioned.
I'll connect the HRV to the existing ductwork so that toilet- and bathroom air will pass through the HRV. For this I made it so that when it's colder outside more air will be extracted in total than is inserted into the livingroom. (When it is not colder then several windows will be open, enough ventilation)

Our livingspace is the warm area, upstairs can be colder. The warm area is well sealed, floor insulation is so-so, which will be my next project. The goal for the warm living area is balanced ventilation with HRV. Upstairs will have some negative pressure, colder fresh air will trickle in, especially via the attic which is actually a useable room (In the Netherlands an attic is livingspace or a storageroom, we insulate the roof instead of covering the floor with a foot of cellulose)

So the HRV will take over from the whole house extraction fan. That single fan (anno 1984) uses more electricity than the 2 in the HRV together, 20,- gain per year on that.

So far I didn't mention the bathroom, it's upstairs and the sketch a few posts above only covers the groundfloor. I did include it in my plans though, it is a place that needs ventilation after all, need to remove the moist from taking a shower, and can recover heat from that.