Supply only ventilation
DaveyBuild
| Posted in General Questions on
Hello. I am trying to get fresh air into my bedroom which is on it’s own hvac central air system. I was going to do an erv but I think it’s probably overkill for one room. I have 400 cfm of bathroom exhaust that goes on and off periodically already in the bathroom in the room. Would adding a supply on ventilation like one attached work? I would duct into the hvac.
The bedroom has a spray foamed cathedral ceiling, rook wool in the walls and blue skin WRB so it’s pretty tight. Thank you.
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Replies
Might be a good application for a ductless through wall ERV. Don’t have personal experience but I’ve talked with a few folks that have them and seem happy with the results.
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The downside to supply ventilation is that you don't get heat recovery, so it costs more to operate than one with heat recovery. If you're in a mild climate, the ROI to go with balanced ventilation might be long, but in a cold climate it will be comparatively fast.
Thank you. The rest of the second floor is serviced with an ERV that is being underutilized. Do you think enough of the fresh air gets mixed between rooms (even on different systems) to not need its own erv?
My main issue is finding area to place the two ducts for an new erv 10 feet apart. Cathedral ceilings are tough.
You can find out for yourself if you use a CO2 monitor. If you keep your bedroom door closed, I bet your CO2 readings are high at night and you would benefit from additional ventilation.
As Moe mentioned, you could use a point-source ERV such as a Lunos E2. If you're very sensitive to sound you might not like it in a bedroom, but it's efficient and effective.
Alternatively, you could have an ERV provide supply air directly into the heating system supply duct; my mechanical engineers are doing that on two of my current projects. I prefer fully separate systems when possible but I know what you mean about cathedral ceilings being a challenge.
Thanks Michael. Just one other thought. I have a foamed attic that I’m simultaneously trying to figure out ventilation for. Would it make sense to install a erv that supplies to this bedroom and exhausts from the attic? I already have a dehumidifier in the attic. Thanks
That would work but I don't think you need mechanical ventilation in the attic if the humidity is controlled with a dehumidifier.