When installing an HRV, can I replace the existing air makeup duct with a tandem duct and plumb my fresh air into the makeup?
bestwrench2005
| Posted in GBA Pro Help on
It looks to me like the air makeup duct on my furnace could be replaced with the new air in from my HRV. Will this constant flow from the HRV upset the pressure balance in the furnace?
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The combustion air needed by the furnace is likely to be many times what the HRV supplies. I can see some technical attraction to trying to use outside exhaust air from a HRV for combustion, but there is very little energy there to recover.
Steve,
The phrase "make-up air duct" is ambiguous. It can mean many things:
1. A duct that conveys outdoor air to a mechanical room in which there is an atmospherically vented furnace. This duct provides combustion air to the room.
2. A duct that conveys outdoor air (combustion air) directly to a sealed-combustion furnace.
3. A duct that conveys fresh ventilation air to the return-air plenum of a furnace.
I don't know what type of duct you are talking about -- 1, 2, or 3 -- but it doesn't really matter, because in all cases, the answer is no.
HRVs ducts must comply with the installation instructions of the HRV manufacturer.
For more information on this topic, see Ducting HRVs and ERVs.
OK, Thank You Martin. Your timely responce certainly keeps me on track with this. And Jon Thanks for your input as well. .