I’m building my own house this summer up here in Maine. It’s likely to be very tight, and I’m considering a heat reovery ventilator. My question is this: does an HRV unit replace things like bathroom fans and range hoods (the system is supposed to draw air from humid or odor producing areas) or work in conjunction with them? It seems to me that a bathroom fan could strain an HRV unit that is trying to draw air from the same small room, but I’m not sure that a duct high on the wall over the stove would be adequate in dealing with kitchen smoke, either.
And does anyone have HRV brands they’d recommend (I’ve looked at Fantech, mostly)?
Replies
My understanding of HRV units (which could be off the mark as I don't have one) is that they recover the heat from air that is being exhausted from the HVAC system, and passes the heat into the fresh air that is being drawn in to the HVAC system. I don't know of one that has anything to do with bathroom/kitchen exhaust fans. Of course that doesn't mean they don't exist.
There are central exhaust fans for bathrooms but I don't think they include kitchens. If you get one, try and locate it away from any bathroom, as they are a bit noisy. I have the one from American Aldes.
Weaf,
Congratulations on the building project. HRV may be used in place of bath vents and as vents in kitchen areas. They are not however recommended as exhaust fans because of the potential for grease and other airborne crud to plug the heat exchanger itself. The idea is to remove moist/stale air from near it's source and replace it with fresh outside air that has been tempered(pre-heated) by passing it through the exchanger to transfer heat. Lifebreath has some very good units as well as filters and a furnace/hrv that runs off a Rianni type H2O heater or Boiler.
Garett
Allow me to quibble...I think HRVs make great exhaust fans for bathrooms. The air in those places is not significantly worse in quality than elsewhere in the house, just the humidity and hydrogen sulfide/methane levels might be a bit higher. Simply suck the air out of those spaces constantly and replenish it either within a return of an AC system or a common hallway.I sized my HRVs so that they can loaf at the lowest speed setting (and highest thermal efficiency) all day. When a person enters the bathroom, a motion sensor from Leviton trips the HRV into high speed, with an adjustable delay. At high speed, my HRVs will pull about 100 CFM per bathroom. The control system is dirt simple, consisting of up to three Leviton ceiling motion detectors (usually used for lights) and the Leviton Powerpak (which can power up to three motion detectors and can dry contact the high-speed setting on the HRV).I totally agree that kitchen exhaust is unsuitable for HRV use.Lifebreath makes most HRV/ERV for the whole NA market. However, also look into the Stirling system from ultimateair.com which is even higher in efficiency.
Is there a quibble here? I want a good quibble.
Garett