Welcome, Guest. Please login or register.
Did you miss your activation email?

Username: Password:

Author Topic: Forced air build  (Read 1245 times)

gandrimp

  • Newbie
  • *
  • Offline Offline
  • Posts: 25
  • OWF Brand: Homemade
  • OWF Model: SMHA (Southern Missouri Hot Air) #001
    • View Profile
Forced air build
« on: February 09, 2013, 09:09:42 PM »

Had new stove bought but the deal fell through at the very last minute.

So I decided to build it myself, I wanted forced air for the simpleness.

I made secondary burn tubes trying to copy the epa free standing stoves on the market.

The door opening is 24x25.

Enjoy
Logged

yoderheating

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 772
    • View Profile
Re: Forced air build
« Reply #1 on: February 10, 2013, 06:50:07 AM »

That is a large furnace, without water how do you plan to keep it cooled enough? I assume you will have the fan turn on whenever it gets to a certain temp? I just know how hot a secondary burn furnace runs. It seems to me you would have to have the fan on every time the furnace draft is open to fully capture the heat.
Logged
www.yoderheating.com
southwest Virginia
MF3000e Heat Master
Heat Master Distributor

Scott7m

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 3719
  • OWF Brand: Heatmaster
  • OWF Model: E Series
    • View Profile
Re: Forced air build
« Reply #2 on: February 10, 2013, 09:46:55 AM »

Yep, to me an air furnace is way more complicated, there is no buffer to store heat and from my experience, they have way more issues.

To each his own though, nice looking build, it's most definitely huge  :thumbup:
Logged
Dealer for:  Heatmaster, Empyre, Natures Comfort, Earth, Ridgewood, and Woodmaster outdoor furnaces
Furnace Parts Dealer
Pelican water treatment systems
606-316-9697

gandrimp

  • Newbie
  • *
  • Offline Offline
  • Posts: 25
  • OWF Brand: Homemade
  • OWF Model: SMHA (Southern Missouri Hot Air) #001
    • View Profile
Re: Forced air build
« Reply #3 on: February 10, 2013, 11:15:37 AM »

There will be a blower that will kick on with a fan limit switch.

A wall thermostat will control the fan in the door and the dampner.

I had concerns about the secondary air and can plug that off if Im not liking the way things perform.

In my area, years ago there were several furnace manufactures, all were built the same way. 2 approx 6" pipes out of the firebox in the back, those 2 tubes went to the front of the furnace where they were joined to an approx 8" pipe that went to the back of the furnace and then to the chimney. Each had a cleanout door. I remember lots and lots of creosote,,, but that could have been that freshly cut oak block throwed in to make the fire last through the night.  Most of these were connected to duct work, many are still in use today and alot of them are being used in shops with no duct work.
I just used 1 chimney pipe hoping for less to no creosote,,, plus my wood will be more cured,,,after I get ahead. Also this will only be used for heating my shop which is rather large with tall ceilings.

I currently heat with a waste oil furnace,, which works very nicely,, when it works. Its 5 winters old and is burnt out. Prices have doubled in the last 5 years = not in my budget.

Hardy OWB is huge in my area and the local dealer is a neighbor/customer but I just couldnt budget for this either.CB is starting to come in the area but I believe he is only selling the furnace, the install is not his thing. Earth and Shaver are kinda local, manufactor wise.

 Right now I have less in the build than the small earth furnace,,,even counting buying a habor freight plasma cutter (which I highly recommend).

Once installed I'll list the good and bad of my design.
Logged

yoderheating

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 772
    • View Profile
Re: Forced air build
« Reply #4 on: February 10, 2013, 11:55:44 AM »

 The biggest concern I would have is if you are building it with a true secondary burn chamber it may overheat on you but I don't have any experience with large forced air furnaces. Are you using firebrick or something else in the secondary burn chamber?
Logged
www.yoderheating.com
southwest Virginia
MF3000e Heat Master
Heat Master Distributor

gandrimp

  • Newbie
  • *
  • Offline Offline
  • Posts: 25
  • OWF Brand: Homemade
  • OWF Model: SMHA (Southern Missouri Hot Air) #001
    • View Profile
Re: Forced air build
« Reply #5 on: February 10, 2013, 03:49:15 PM »

This is more of a free standing stove (that has secondary tubes) copy and not a secondary chamber. I have a Jotul castine free standing stove in my house. The secodary tubes just bring hot fresh air into the fire chamber which then fires off the smoke, gives good burn times on a pretty small amount of wood. With this design of course the wood burns, but alot of times the flame doesnt really even touch the wood, its just the smoke burning, quite relaxing to watch. Its also very clean in the chimney area.

The secondary you are talking about does get to extreme temps that I am not expecting with this setup.

This is different than any furnace I have seen, and I realize it might not work the way I hope for it to.

Logged

yoderheating

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 772
    • View Profile
Re: Forced air build
« Reply #6 on: February 10, 2013, 04:22:22 PM »

 Oh I see now, I thought you were saying you were designing it after the phase 2 epa stoves. Sorry about the confusion.
Logged
www.yoderheating.com
southwest Virginia
MF3000e Heat Master
Heat Master Distributor

Scott7m

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 3719
  • OWF Brand: Heatmaster
  • OWF Model: E Series
    • View Profile
Re: Forced air build
« Reply #7 on: February 10, 2013, 08:01:44 PM »

I would sure like to have a food jotul or efel, a design like that in my home for emergency backup
Logged
Dealer for:  Heatmaster, Empyre, Natures Comfort, Earth, Ridgewood, and Woodmaster outdoor furnaces
Furnace Parts Dealer
Pelican water treatment systems
606-316-9697

Dragfluid

  • Newbie
  • *
  • Offline Offline
  • Posts: 9
    • View Profile
Re: Forced air build
« Reply #8 on: January 25, 2014, 05:05:43 PM »

Had new stove bought but the deal fell through at the very last minute.

So I decided to build it myself, I wanted forced air for the simpleness.

I made secondary burn tubes trying to copy the epa free standing stoves on the market.

The door opening is 24x25.

Enjoy
I was very interested in this build.  Did it ever get finished/used?
Logged
98 K1500
Case 1845C
Stihl 044
Stihl 025 (both with REAL chains)

mlappin

  • Global Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 666
  • OWF Brand: homebuilt
  • OWF Model: Martin Steel Works Gen 1
    • View Profile
Re: Forced air build
« Reply #9 on: January 28, 2014, 08:00:37 PM »

gandrimp, if you still have old oil to get rid of look here for a simple to use and build oil burner. http://www.wasteoilheater.net

I've used the same in my shop for ten years now, no problems, just change out brake drums every couple of years. Converted my wood furnace to house it in.
Logged
Stihl 023
Stihl 362
Stihl 460
Sachs Dolmar 112 and 120
Homemade skid steer mounted splitter, 30" throat, 5" cylinder

gandrimp

  • Newbie
  • *
  • Offline Offline
  • Posts: 25
  • OWF Brand: Homemade
  • OWF Model: SMHA (Southern Missouri Hot Air) #001
    • View Profile
Re: Forced air build
« Reply #10 on: February 16, 2014, 08:35:51 PM »

UPDATE: I believe my secondary burn tubes really don't help due to the wood I burn, if I can pick it up and it will fit in the door I burn it. Its also hard to cure a 3' length of wood. An 8" stick of wood 36" long is heavy, so the bigger around the shorter I cut. My box depth is 42" and if I recall the door is 25" wide and 27" tall which is perfect but my door weighs around 300lb.
I didn't use fire brick, just let the ash get a couple inches deep, shovel ash from the front and rake coals forward every 3-4 days. The chimney stays surprisingly clean. I wish I had used 8" chimney for more draft instead of 6" just for when I open the door.
What has really impressed me is I can load the stove on top of coals, shut the tstat off, and seven days later still have coals enough to start a fire.
I put the air intake low in the building, and the heated air comes out of the top of the stove, so there is always a flow of hot air coming from the hot side.
Over all Im happy with the way it works and it was a fun build.
Theres 2 things I would do differently, 8" chimney and I would put a second blower to the firebox with a second tsat set at a lower temp for bringing it all up to temp faster,( bigger chimney might make this unnecessary).
Sorry this is so rattlebrained, just typing as I think or is it thinking as I type?
Logged

gandrimp

  • Newbie
  • *
  • Offline Offline
  • Posts: 25
  • OWF Brand: Homemade
  • OWF Model: SMHA (Southern Missouri Hot Air) #001
    • View Profile
Re: Forced air build
« Reply #11 on: February 16, 2014, 08:47:11 PM »

I would also like to add,,,, that my stove smokes no worse than the Hardy and Shaver stoves I see.

My building is 40X80 , 17' to the peak with 2-12x12 and 1-14x12 doors.
Logged

dave_dj1

  • Newbie
  • *
  • Offline Offline
  • Posts: 41
    • View Profile
Re: Forced air build
« Reply #12 on: February 17, 2014, 03:10:36 PM »

I like it. Is this outside?
dave
Logged

slimjim

  • Hero Member
  • *****
  • Online Online
  • Posts: 2445
  • OWF Brand: portage and main
  • OWF Model: Enviro 500 wood chip boiler
    • View Profile
    • www.mainlycustom.com
Re: Forced air build
« Reply #13 on: February 17, 2014, 04:16:18 PM »

Radiant slab I hope!
Logged
Portage and Main dealer
trouble shooting rep in northeastern US and Canada

gandrimp

  • Newbie
  • *
  • Offline Offline
  • Posts: 25
  • OWF Brand: Homemade
  • OWF Model: SMHA (Southern Missouri Hot Air) #001
    • View Profile
Re: Forced air build
« Reply #14 on: February 18, 2014, 12:37:25 PM »

It is outside.

Forced air.
Logged