Question about HRV system

  • Active since 1995, is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.


Minister of Fire
Dec 4, 2017
NW Ontario
Hey all,

I’ve got a question for the very knowledgeable group about my current HRV set-up. A little bit of background first might be helpful: I have a propane furnace forced air set-up, an HRV system that is looped into the furnace duct work, and a wood stove. I try to keep the stove going as much as possible, however we do have the furnace kick on too, especially when the northern Ontario winter sets in.

We moved into the house several years ago, and i had the wood stove installed last fall. When we moved into the house, i noticed what i think is an incorrect set-up of the HRV fresh air and exhaust air. I was hoping you all could give me some advice. I’ve just installed an Ecobee4 thermostat, so now the HRV and furnace are running on the same device, and it’s got me thinking it might be time to address the HRV.

Currently, the HRV fresh air duct to the house runs into the hot air duct that comes off the top of my furnace, just upstream of the hot air exiting the furnace. The HRV duct that evacuates air from my house is tied into my return air duct just before it feeds into the furnace. This is backwards, isn’t it? I’m pretty sure that the HRV fresh air duct is supposed to feed into the return air, right?

So, the obvious thing to me is that my HRV is likely very ineffecient - kinda like peeing into the wind. I don’t know how much fresh air exchange can be happening when the furnace fan/HRV is running, but there is a difference in the air quality with it on vs off, so it is doing something. However, now that the HRV and furnace are running off the new t-stat, whenever the HRV kicks on it kicks on the furnace fan too.

I think i’m going to have someone come in and fix it up, but i’m wondering if there’s any other issues with having the system set up backwards like this? I’m also wary of the system creating a pressure balance issue in the house which could cause my stove to backpuff, although it hasn’t happened before.

Just canvassing the group for thoughts, suggestions etc.

Thanks in advance!
This help?
Our school looked into this fresh air concept hospitals use it I have seen and felt it in commercial kitchens. our school finally gave up on it the doors are opened constantly anyway. As expensive as heat is I think it would make your heating even more expensive!
ya i'm gonna have my HVAC guy come and take a look at it and see if there's a way to improve the system.
  • Like
Reactions: k0wtz