2nd floor chimney chase heat recovery

[Testocules]

Hi All, new to the forum here, glad to have found this resource for experience-based information!
I've been digging on information related to capturing heat from a second floor chimney chase.
I'll be sure to follow the codes of my location here in Nova Scotia, Canada, but if they permit I'm interested in knowing if anyone has done something like this...
My plan would be to create a chase by boxing in my class A pipe (floor to ceiling of second floor) that passes through the second story of our house (stove is on main floor and vents straight up through the middle of the second story, then through the roof - no bends). By code, it sounds like the boxing in isn't an issue.
I'd then make an opening in the chase at the ceiling level of the second story, and another opening at the base of the chase at the floor level of the second storey...I'd put a bathroom fan on the upper opening to create a positive pressure in the chase which would then push the warmed air out through the floor level opening.
The 'reclaimed heat' would help heat the second floor.
If this is ridiculous for code or safety reasons I'd certainly not proceed...I'm just having trouble finding anyone who's done this...perhaps because it is ridiculous for some reason?
Thanks for any help understanding why this is or isn't a reasonable possibility!

 

[begreen]

I'd just put a grille at top and bottom, no fan. Natural convection will occur without much help.

 

[Testocules]

Thanks Begreen - agreed on the natural convection, but my thought with the fan is that the heat would be broadcast at floor level then rise through the room versus exiting at the ceiling and remaining primarily there...room ceiling is only 8' so perhaps it wouldn't make much of a difference...was just considering that 'cold feet' thing where the heat in a room tends to sit a the ceiling and the colder air on the floor.

 

[maple1]

I don't think you'd get much heat out of it. Mine is barely warm to the touch. So after a few minutes your fan would just be moving room temp air around.

 

[Testocules]

Thanks maple1, I wondered about that too, just how much heat I could expect to pull off an 8' run of class A pipe that's designed to be relatively cool to the touch...may not get the results I'd be hoping for if the enclosed chase wouldn't capture enough heat off the pipe.

 

[begreen]

There is some heat there. Our class A gets up to around 125º a few feet above the floor. I'd just vent it and see how it works.

 

[Testocules]

If the 'forced air enclosure' may not work as intended, I'd likely not enclose the pipe at all...keeping the whole pipe exposed might radiate more heat into the room from bottom to top than boxing it in and convecting it through the chase to the ceiling only. If there's enough heat worth capturing, the enclosure/fan might help put the heat where it would be more useful - across the floor and a bit further through the room versus a perimeter distance off the pipe, and the ceiling. If the pipe is achieving 125 degrees, I may give it a go.
I can't imagine there'd be any concern of smoke or flue gas in the chase as the pipe is designed to be exposed anyway...would there be any other code or safety concerns that I should consider? Thanks for info and perspective.

 

[begreen]

Locally code requires the pipe to be chased when passing through floors. Not sure about your area. Safety appears to be why. A friend created a safety screen out of perforated stainless steel for his chimney pipe and the inspector approved.

 

[Testocules]

Interesting...I'll double check code on that again for our location...if a chase is required here too, I'd likely give the forced air approach a try...I also like the perforated metal or metal mesh chase idea as an alternative - it would surely allow any available heat to radiate off the pipe into the room, and sounds like it could satisfy the chase requirement as well.

 

[Squirrel]

I have a chase running through the corner of a bedroom upstairs. I would have chosen not to have a chase at all but had to for regulations. My first choice was perforated metal but that was not allowed by the decorating supervisor who would be sleeping with me in that room. I ended up with a steel studded drywall enclosure with a vent top and bottom.
There is a slight movement of warm air through the top vent when the stove is burning hard for a long time but so little heat that a fan of any kind would be wasting energy.