Wood Furnace Questions Shelter SF1000e

[psbarnwell]

Hey all,
I'm new to using a wood furnace (three days). My wife and I decided to install a Shelter SF1000e to tie into our existing oil furnace duct work. I've read some somewhat unfavorable reviews of this unit, but I'm hopeful it will do the job for us. For heating the whole house, I can already tell that the unit is a little small for our rambling old cape farm house, but since we don't use 1/3 of the house regularly, it seems to provide enough juice to warm us up (we rarely heat about 65 degrees in the winter). Plus we can still use the oil furnace if necessary. I'm not having any issues as far as I can tell with functioning, I'm wondering about a few things:

1. The unit has to be connected to a thermostat, which seems to be fairly useless besides kicking on the draft blower to get things started if the set temperature needs to be reached. Once the set temperature is reached, it doesn't seem to matter what I do with the thermostat. Is this normal?

2. Once I have a strong fire going, the circulation blower kicks on frequently for short bursts (especially if the thermostat temperature is already met. Is this an automatic function due to the furnace needing to cool itself down? I'm thinking this is normal?

3. Lastly, as you can see from the attached pic, I don't have any air return ducted to the back of the unit. Are there any pros or cons to this approach? The furnace is sitting in the basement. Is there any reason why I should consider ducting from the existing return air system to the back of the wood furnace?

Thanks for the insights!

 

[psbarnwell]

Ok--another question. The wood furnace is off, no fire, and I tried turning on my oil furnace. Because the hot air from the oil furnace returns to the wood furnace hot air chamber, the wood furnace circulation blower just turned on as it warmed up, creating competing forced air. Is this bad? If I'm not home or don't feel like using the wood furnace, it'd be nice to use the oil without complications...thoughts?

 

[psbarnwell]

Ok--another question. The wood furnace is off, no fire, and I tried turning on my oil furnace. Because the hot air from the oil furnace returns to the wood furnace hot air chamber, the wood furnace circulation blower just turned on as it warmed up, creating competing forced air. Is this bad? If I'm not home or don't feel like using the wood furnace, it'd be nice to use the oil without complications...thoughts?

Is this what I should install?

Master Flow 8 in. Damper D-8 - The Home Depot

Master Flow Dampers balance and adjust the air flow in individual runs of round pipe in HVAC systems. The dampers include hardware that makes it easy to install into existing round pipe as well. They are constructed of galvanized steel for durability. Only one wing nut is required for installation.

www.homedepot.com

 

[Gearhead660]

Sounds like you need to address a couple things to get it running better.
Would benefit from connecting to existing return duct. Right now you are pulling cold air from basement floor.
There are 2 8" supply ducts on top of the Shelter? I would have both ducted to supply trunk.
Need back flow dampers installed. That is why the Shelter blowing is kicking on when the oil furnace is running. Need them in the supply and return.
The short cycling of the plenum blower is a common issue with these furnaces I believe. Do a search on this forum, lots of info for this furnace.
The thermostat controls the draft blower, makes the fire burn hotter when heat is being called for.
Hope this helps a bit.

 

[psbarnwell]

Hi,

Thanks for the reply and tips! So if the return air is cold from the basement floor, it's mixing with the hot air to decrease efficiency, right?
I decided to try capping one of the supply ducts as an experiment. The air flow is OK, but not nearly as powerful as my oil furnace. Would having them both tie into the supply trunk make that much of a difference?

My first move is to get a manual 8 inch round damper to install, which should be pretty easy. Definitely learning a lot and despite this furnace's sketchy reviews, I'm hoping that it does what we need.

 

[brenndatomu]

That second duct really needs to be hooked up...it's designed to push out heat and cfms through 100 SQ inches, not 50...those units are well known to run hot and warp/crack as it is.

Pulling cold air from the basement increases blower cycling and decreases heat output...return ducts should be hooked up and dampers installed to prevent backfeeding from the oil furnace