ERV V150E75NT airflow problems
Hi, I have a recently renovated 100 year old home (2100sq ft on 3 floors) with a newly installed Vanee V150E75NT installed alongside a small air handler.
The unit claims to be rated at 138 CF at 0.2 wg / 129 CFM 0.4 wg
The installer appears to have configured the unit for max airflow of 45 CFM.
The unit is installed with 5″ flex ducts running about 15 feet from the ERV to outside, and 5 feet to the return trunk of the air handler’s duct work.
Running the airflow test, I’m only getting about 35 CFM, even at the MAX setting.
My question is, are those numbers completely bogus? Is it normal to actually get 1/4-1/3 of that airflow with an installation such as this?
Thanks in advance
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Replies
They probably configured your max setting to be that cfm, i don’t have the vane but most have a config setting that lets you set min medium and max settings
Check page 15: https://www.markssupply.ca/ASSETS/DOCUMENTS/ITEMS/EN/vanEE_V150E75NT_Installation_Sheet.pdf
You likely need to modify the max CFM value.
Thanks for the replies, it turns out there was a defective motor, waiting for a replacement. Still not sure why it was *configured* with such a low max cfm.
2100 square feet, 3 levels, 100 year old house (heavily retrofitted) is very close to our setup. With 4 occupants and two cats, the automation system is often dialing in ventilation at 50 CFM and with everyone home, and all windows closed, it will ramp to 60 or 75 CFM to maintain ~800 PPM CO2. With two occupants, 45-50 CFM will likely work...so the installer may not be far off if there are just two in the house. If 3-4 occupants, you'll want to dial in 60-75 CFM. I average CO2 values from the sensors on each floor, but trigger higher vent rates if radon or VOC spike on any floor.
I believe ASHRAE is still 7.5 to 10 CFM per person which I think is a tad low (at least in our situation) to keep VOC, and Radon at acceptable levels. ASHRAE considers CO2 as a "tracer" gas to give an indication of ventilation rates, which makes a lot of sense as I've found just automating on CO2 (particularly turning off the system with CO2 PPM below 500) does cause IAQ issues. My wife's nose is remarkably effective with respect to IAQ, and the above levels work to keep her happy :-)
This is a good current read: https://www.ashrae.org/file%20library/about/position%20documents/pd_indoorcarbondioxide_2025.pdf