installing HRV

[lexus300rb]

I plan to install a HRV system to save on labor costs and have a local dealer checkout and balance the system afterwards. My install questions, what is the maximum length I can have going to an exterior wall from the HRV unit using 6" duct? Also, what is the reason for not installing the fresh-air and stale-air duct on the vertical drop down of the return air plenum? My return air plenum T's just above the furnace going to separate ends of the house. Haven't decided yet on manufacture but leaning towards a Bryant unit. I have total area of 4000sq ft (includes basement) so with my calculations I need a unit that will handle at least 186 cfm.

[beenthere]

Questions and discussions pertaining to HVAC for the home. No pricing, no DIY, Thank You.

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Your local contractor can answer those questions. The one you want to use to balance and check out the system.

[DanW13]

Best bet is to use hard duct unless your running duct work in unconditioned space such as attics, crawlspace use insulated flex, and put a dampers on all exhaust points to balance the unit. I'm currently installing my ERV and am using hard duct, busting a couple of walls open and will only have flex in my attic space from my intake and exhaust and one for my supply into the return. It's alot of screwing around but will be worth every minute of my time when it's all done.