Integrating Ducted Mini-Split with HRV
I am currently trying to come up with the best solution to heat AND ventilate 3 upstairs bedrooms. I don’t have a ton of space for the mechanical and I am trying to come up with a solution to isolate the systems from the living/sleeping space. I do think I would like to put the HRV unit in the basement and run flex tubing up to the 2nd floor and tie it into the limited short duct runs that will be coming from the slim ducted mini-split unit I hope to install in the ceiling. I feel pretty good about the ducted mini-split installation and short runs of tubing that I have drawn. Additionally, I am planning on using passive returns in the doors to hopefully get everything to flow back to the hallway and into the register/plenum.
A lot of HVAC pro’s are recommending that I need more ductwork (i.e. dedicated returns for each room) but I think I have a fairly reasonable solution. My climate is zone 6 (cold) so I am mostly designing for heat however the bedrooms are west-facing so I am going to have to manage the heat buildup. I am attaching a couple renderings. My main question concerns the ability to attach a fresh air intake on some of these ducted mini-splits. In all my research, I haven’t seen if the units have an integrated “knockout” that might accomodate a fresh-air flex tube. I am thinking I will just fabricate/extend the rear return plenum so that I can have a port/entry/knockout for the HRV. If I do this, my goal will be to make sure that I get clean conditioned air into the rooms. I am hoping the ductwork shown doesn’t have too much static pressure to overcome. Thanks in advance if anyone has any feedback or thoughts.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part