Ventilation duct length
Dakota_G
| Posted in Mechanicals on
I’m looking into incorporating an ERV ventilation system into a new construction design, but the location of the mechanical room will result in long duct runs (50 – 60 ft) from the ERV to the bathroom exhaust registers and the bedroom supply registers. How long of a duct run is too long for an ERV and/or what is the appropriate duct size to use for an ERV with duct runs this long? Continuous CFM requirements are Between 60 and 80 CFMs. I’m looking at the Panasonic Intelli-Balance 100 ERV.
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Replies
Dakota,
Here's a link to a useful online calculator:
"Broan maximum duct length calculator."
For example, a Broan 100 HL fan rated at 80 cfm with 2 elbows has a maximum duct length of 17 feet if you are using 4 inch smooth ducts. Switch to 5 inch ducts, and you can run your duct for 161 feet.
Different model numbers have different fan ratings, of course, so this calculator may not work for you unless you can find a Broan fan that closely matches your Panasonic fan.