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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Replies
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.
I would checkout the chart at this Energy Vanguard link. https://www.energyvanguard.com/blog/best-velocity-moving-air-through-ducts/
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.