Installing Registers off Wood Stove Furnace

[Gilly826]

Hey all,

It's been a LONG time since I've been on here, good to be back now that we have a HOUSE again... well sort of good anyhow

Our house is roughly 1600sq.ft and it primarily heated via a wood stove which is centrally centered in the dining room/kitchen area, and has a secondary propane unit in our living room. The wood stove does great at heating the "heart" of our home while we are there to keep the fire fed, but temps die down overnight and especially while we are away at work, which leads to my topic of discussion....

In the basement is a BIG Fire Chief- FC300F (80k BTU Max.) wood stove which comes equipped with a blower unit capable of delivering 500 CFM through 8" round ducting, which is the size of the collar coming off the unit itself. It currently has NO DUCTING installed and literally blows hot air straight up at the ceiling. I'm exploring better options to put this unit to use...

I would like to install registers in the bathroom, kitchen, and dining room area. I would also like to have a couple of vents coming off the main ducting to supply additional heat into the basement when I am working down there. Does this sound reasonable, and how exactly should I go about this?

Here are some questions/topics of concern:
- Do I branch off of the 8" trunk, or keep everything at 8 inches?
- Should I run a smaller branch just to the bathroom since it is a much smaller area than the kitchen/dining room area?
- Do I need to run return vents through the flooring, or can I route a supply vent through the basement window? (recommended by chimney sweep/install company)

Interested to hear your thoughts... Thank you!

 

[Snoonyb]

These systems are designed to not only recirculate heated air, but they also use the spaces air, as combustion air, and often require a system dictated size of exterior cold air, for combustion, which would be prudent for you to review.

The owners Manuel also recommends that you properly maintain the ash drawer.

The distance from, as well as the number of areas served will determine the end size of the 8", when viewing it as a manifold.

Your use of the living space should also be a primary consideration, where several 6", with adjustable dampers may well serve you primary occupancy, 4" may serve the bedroom/s, bathroom, laundry, and cold porch. Or, everything 6" with dampers.

Your chimney sweeps recommendation of a cold air supply would also recommend insulation of the ducting, and your owners manuel has recommendation for duct installation and connection.

 

[PJB12]

Hello Gilly826,
In the way back days, often a coal or wood stove was in the basement and a short length of duct was run to the ceiling above the stove. A rather large hole was cut in the floor. Upstairs a walk-able grate was installed over that hole. Maybe that will work for you.

The heat rose through the grate and circulated through the house by gravity. (Heat seeks cold). Often a second, larger, grate was directly above the first one to heat the second floor. (No ducting between) Return air wasn't a consideration. It found its way back through leaks in doors, around pipes and such.

My house was originally heated like this. You can still buy these large grates.

This was the early form of Gravity Hot Air. In the later Gravity Hot Air, a dome plenum with sand on top had ducts that branched off like an octopus. (Actually the furnaces were called Octopus Furnaces) The ducts ended at floor grates like described above.

Paul