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View Full Version : Energy Recover Ventilator (ERV/HRV) for VOC exhausting in a workshop setting



R Mousel
01-15-2024, 5:47 PM
I was thinking of putting in an ERV system for ventilation of VOC's in my basement workshop, northern climate (No system currently). Chemicals of concern: denatured alcohol, paints, stains, resins, glues...etc. I was all set to buy but then was thinking about if there is any transmission of fumes across the membrane--it transfers a majority of the humudity so was wondering if that would be the same for the fumes I am trying to get rid of? I found a study looking at isopropyl and acetone transfer, but my scientific paper understanding ability is not great. The result shows transfer, but how much is too much?
If it only passes a small percentage and if I am turning the air over quickly, will it matter?(anything is better than I have now) Maybe if it is run at high speeds during high VOC use, slowest speed in most of the time. Maybe I should go with a small HRV and close off the area where fumes are(downside is it brings in too much humidity during the summer) Any thoughts? Not interested in just normal exhaust fan because of extreme climate.

Here is the article:
https://www.researchgate.net/publication/361073642_Contaminant_Crossover_in_Residential_Ene rgy_Recovery_Ventilators_Mass_Spectrometric_Analys is_and_Introducing_Remediation_Measures

roger wiegand
01-15-2024, 6:39 PM
You can make a heat exchanger without the semipermeable membrane that might be more effective to exhausting the bad stuff while keeping much of the heat. It's not just how well it performs when new but also over time being eroded by organic solvents. I'd solve the humidity problem with a humidifier or dehumidifier depending on season and go with an impermeable heat exchanger to ensure getting the organics out of the space.

Bert McMahan
01-19-2024, 12:03 PM
An HRV (heat recovery ventilator) doesn't have a transfer membrane like an ERV (energy recovery ventilator), so it'll keep your heat but not the moisture or the fumes (as I understand it). Being in MN I'd guess you're mostly worried about heat, not moisture, so an ERV isn't necessary. I believe ERV's are better in places with high humidity- for example, here in TN, my AC unit does a lot of work just pulling moisture out of the air, so an ERV keeps the humidity outdoors during the summer. During the winter it's not a big deal as I don't humidify my air anyway, so the humidity isn't anything to worry about.

Jim Becker
01-19-2024, 8:31 PM
These systems are not really aimed at things like VOC. If you are using solvent based finishes, such as lacquer, you need proper explosion proof ventilation. Personally, I wouldn't be comfortable using them in a shop that's physically located in a home and I honestly don't use them in my detached shop, either.

Bill Dufour
01-19-2024, 11:15 PM
I would wonder how soon they get plugged by sawdust and can they be cleaned.
Bill D

roger wiegand
01-20-2024, 8:26 AM
These systems are not really aimed at things like VOC. If you are using solvent based finishes, such as lacquer, you need proper explosion proof ventilation. Personally, I wouldn't be comfortable using them in a shop that's physically located in a home and I honestly don't use them in my detached shop, either.

I really think it depends how tight your building is. Agree completely that it is no substitute for proper ventilation if you're doing things like spray finishing, but you may also want one for exactly the same reasons you'd put one in your house. With a shop built with modern air sealing standards or a basement shop in a well built house with minimal air exchange some mechanical ventilation may be required to maintain decent indoor air quality just for the normal VOC producing activities one does in a shop. I think few of us have a spray booth and explosion proof fan if we're doing a glue up with epoxy, putting a seal coat of shellac on a few small parts, or applying wipe on poly to a bowl on a lathe, yet those activities generate things in the air we'd be better off not breathing.

Even for a serious exhaust fan in a more extreme climate I think a heat exchanger would make economic sense if the vent were running any significant fraction of the time. A fan pulling a couple thousand CFM could reduce the temperature in most small shops by 50 degrees pretty easily at this time of year without a serious investment in a heated make up air source; a heat exchanger could greatly reduce that load.

Jim Becker
01-20-2024, 10:23 AM
I don't disagree that air exchange is a valuable tool for a building, Roger. I was just pointing out that it's not for dealing with dangerous VOC and other things like that.

R Mousel
01-20-2024, 1:25 PM
The climate gets extremely humid in summer, extremely dry in winter. Reason I would like to try to use ERV instead-I believe ERV's are recommended everywhere unless you live in the desert and donj't have humidity at all.
I have no plans of doing any explosive solvent spraying other than an occasional quick spray with spray paint in the winter, generally save big stuff for outside. I mostly use water based with some shellac for finishes, some epoxy and of course the super glue fumes. I would build an intake filter box of some sort so I don't worry about dust clogging, although I think the HRV cores are washable, so benefit there. More I think of this, maybe an HRV paired with a large dehumidifier for incoming summer wet air would be best for this situation, winter humidity is easy to take care of.