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HRV retrofit for a basement

I live in North Vancouver, BC, marine zone 4/5 and am renovating an older home.
The basement was finished years ago as a suite, to about R30 so I am not interested in redoing it.
The problem is we don't have enough ventilation in some of the rooms due to the fact that it is mostly a direct vent gas fireplace heating it.
Cold air returns are virtually non existent.

I was thinking of installing an HRV to provide more ventilation.

The spaces in the basement are a bedroom, bathroom, laundry room, a kitchen/living area and a separate family room.
The suite is about 600 sq ft and the family room about 300 sq ft.

The HRV would be installed in the furnace room which is centrally located.
I can get fresh air and exhaust stale air without too much difficulty to the HRV.

The family room and bathroom are the easiest as they are right beside the furnace room.
The kitchen won't be too difficult either.
The laundry room is the most problematic has it can become humid and is separated by stairs from the furnace room.
The bedroom is also separated by the stairs.

I am somewhat constrained by the fact that all ducts would have to run through the ceiling joists.
However, I may not have enough space in the ceiling joists to provide supply AND exhaust lines to each room.
It may also be difficult to provide enough distance between the exhaust and supply vents in each room.

While trying to maintain a balanced system, if I have to choose, is it better to provide fresh air or exhaust stale air from a room?


PS. I am also renovating the main floor so I have the ability to access the space in the ceiling joists in some rooms by opening the subfloor on the main floor.
And to throw a screw into the works, I would also like to use the HRV for the main floor.
However I am not as concerned because ventilation is supplied by the forced air furnace and cold air returns.

Asked by Aaron Gatzke
Posted Aug 24, 2014 7:48 PM ET
Edited Aug 25, 2014 10:46 AM ET


6 Answers

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I'll leave advice on your question to more knowledgeable posters, but just wanted to flag that if the suite is a separate dwelling unit you should check whether you can have any ducts penetrating the ceiling as it is a fire separation.

Answered by Malcolm Taylor
Posted Aug 24, 2014 8:51 PM ET


Hi Malcom,

Thanks for the reply.
It is a guest suite for ourselves.
My wife uses the kitchen for the stuff she doesn't want to cook upstairs or it is too hot!

Answered by Aaron Gatzke
Posted Aug 24, 2014 9:59 PM ET


"My wife uses the kitchen for the stuff she doesn't want to cook upstairs'

Makes boiling down that chicken or fish stock a lot more pleasant! Hopefully someone will be along shortly with some more useful advice than I gave you.

Answered by Malcolm Taylor
Posted Aug 24, 2014 11:28 PM ET


The typical way to design such a system would be to pull exhaust air from the bathroom and laundry room -- and possibly from a ceiling grille in the kitchen, as long as the grille was located a decent distance away from the range hood -- and to supply fresh air to the bedroom, living room, and family room.

Most manufacturers of HRVs post their installation instructions online, so you should be able to download the instructions for the HRV you intend to purchase. Ducting details like these are discussed in the installation manuals.

For more information on the GBA site, see Designing a Good Ventilation System.

Answered by Martin Holladay
Posted Aug 25, 2014 9:59 AM ET
Edited Aug 25, 2014 10:00 AM ET.


Thank you Martin!

Answered by Aaron Gatzke
Posted Aug 25, 2014 12:18 PM ET


I'm no engineer or HVAC guru, but I don't think your furnace provides ventilation.

Answered by stephen sheehy
Posted Aug 26, 2014 1:04 PM ET

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