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Community and Q&A

Sizing HRV Ductwork

JIM BAERG | Posted in Mechanicals on

I’ve designed and installed a few HRVs but have always done it by the seat of my pants using rules of thumb and good practices.  I’ve read a lot but have never found an easy way to size ducts and fittings.  The one time we had a system tested by a certified tester, we found low flow in the Master Bathroom.
I understand that Manual D would be one approach to doing that sizing, but it seems like it has a steep learning curve.  Can you point me to any literature, software or websites that might help?
thanks,  Jim

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  1. GBA Editor
    Kiley Jacques | | #1

    If you are able and willing to pay a consultant, Allison Bailes of Energy Vanguard is the go-to guy. At the very least, he could point you in the direction of software/resources.

  2. kyle_r | | #2

    I would checkout the chart at this Energy Vanguard link.

    Keep the velocity below 400 ft/min. Try to limit the amount of elbows and look up the equivalent length of any other fitting you plan to use to make sure it’s not too ugly.

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