fresh air intake vs. cold air return

fresh air intake vs. cold air return

PostBy: stokerstove On: Thu Oct 04, 2007 7:03 pm

I'm about to re-do the fresh air intake for my Alaska Stokerstove and after reading about the benefits of using cold air return ducting back to the stove, I'm not sure of the best way to go.
The house is a 1500 sq. ft. 2-story with the stove in the basement. I have a fan assisted register in the first floor above the stove and another (not fan assisted) above that in a second floor bedroom.
I figured the stairways would provide a natural cool air return. There is no existing ductwork in the house and the heating sys. is elec. baseboard.
Thanks
stokerstove
 
Hot Air Coal Stoker Stove: Alaska Kodiak Stokerstove 1

PostBy: LsFarm On: Thu Oct 04, 2007 8:19 pm

Hi Stokerstove, The fresh air intake and a cold air return are two different items. And a good stove installation will have both.

A fresh air intake is to provide outside air for the combustion of the coal. This should be a pipe from outside to near or attached to the intake of the combustion fan. A screen on the outdoors end of the pipe will keep mice outside. Some people just open a window a 'crack' in the basement to provide fresh air, but this cools down the whole room, and creates a need to burn more coal to heat the cooler air.

The cold air return will create a positive circulation of hot air throughout your house. Cool air returning to the stove from the same rooms or parts of the house that you are pushing heat into will create a loop of heated air. This circulation is crucial to getting even heat through your house.

Many stove owners use open stairways as cold air return passageways and they work OK. But in some houses it just doesn't work. And some form of a cold air return is needed. If you have open floor joists in the basement, you may be able to put a simple duct from the farthest end of the house hooked to a floor resgister to the inlet of the distribution fan in the stokerstove. This will provide a positive return of cool air to the stove to be reheated and recirculated.

Greg L
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

PostBy: stokerstove On: Thu Oct 04, 2007 9:04 pm

Thanks, Greg. I already have a fresh air intake that I hooked up last year. From the info I read I thought some were hooking their cool air returns up to their combustion fans - that is where I must have gotten confused. I thought I had to choose between outside air or returned air at the combustion fan.
It seems that I am probably doing ok with the system as it is. It would be pretty tough to get any ductwork from the farthest point from the stove - on the second floor, but I'm thinking that a return from the farthest point on the first floor might help as I do have open floor joists in the basement.
stokerstove
 
Hot Air Coal Stoker Stove: Alaska Kodiak Stokerstove 1


PostBy: LsFarm On: Thu Oct 04, 2007 9:15 pm

Hi Stokerstove, There was a forum member last year that had put hot air ductwork in, then added booster fans to the ductwork, and was still having trouble getting somewhat even heat thoughout his house.

He installed a simple floor register at the far end of the house and hooked up 4" dryvent hose to the inlet of the distribution fan housing. He immediately had a near perfectly even heat through the house. This is pretty amazing considering the hot air ducts were 8" and fan augmented as well.

Just food for thought. It shows how important the circulating loop of air is.

Greg L
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland