HRV duct work set up
CZ 7 Northern MN, 2×6 standard frame with 4″ exterior foam. Mini-split with back up electric baseboard in a 30×50 1500 square foot one level with unvented crawl space. 50′ southern exposure with master BR and Live/Dine/Kitchen great room facing south. All mechanicals DIY. I read most of the QA on HRV’s yesterday, and I think I will go with an HRV in the mechanical room (center of house north side) and am wondering how the duct work would look. I am thinking; single supply into the great room above the television, which will be on the wall between MBR and Great room. Exhaust in the master bath and laundry on one exhaust branch, which will draw fresh air into the MBR and the master bath. The other exhaust branch in the second bath, dining area just off kitchen area and spare BR. Just the two of us, but we will have occasional over night guests. Each exhaust branch will be somewhat close in length; one will have two vents, one will have three vents. My question is, can I neck down the duct where it splits to pick up multiple vents. For instance, I will have a tee splitting to two branches; can I neck down to 3″ for each branch. 4′ is 12 square inches, two 3″ is 14 square inches, so always maintaining as much or more square inches of duct area after a split. Any other observations also welcome.
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