Wood burning workshop heater- ideas ??

[Renze]

quarter inch is 6.3 mm... Good, this thickness is still readlily available on scrapheaps and welding shops..

Hey i'd thought i should tell you this, because i changed my plan:
Yesterday it was about minus 5°C and i ran out of old engine oil to burn in my oil burner.. So i decided to load the oil burner with firewood....
The result was that the flames, normally just burning inside a 20x20 cm oil pit, now burnt from wood lying to the sides of the heater. The black creosote oil sludge on the "ribbed sides" (which turned out to be upright heat exchanger pipes /forums/images/graemlins/grin.gif ) crumbled off the inside of the heater, causing intermittent clouds of black smoke, and now, the heater looks a lot bigger when you look into it... Soon i took off my coat and i was sweating wearing coveralls... /forums/images/graemlins/shocked.gif

I assume that the half inch layer of tar on the heat exchager pipes, were insulating the heat exchanger pipes causing most of the heat to be blown out of the chimney...

So what i learned from this experimental pyromania is that i have a very efficient heater with heat exchanger, exhaust fan and forced air circulation.
I just need to find a fuel other than used engine oil as this clogs up the inside of the heater, and i'm only getting 120 liters each year from oil changes, that includes used oil form 3 neighbors.

So i decided that the easiest and cheapest option is to convert this oil heater to wood.

I think i am going to weld an ash tray for it, with a little cover over the oil burning pit (which is also the entrance point of the combustion air, through perforated sheetmetal) to prevent ashes clogging the air intake.

Would it make sense to put these oven stones in my to-build ash tray, and would an oil heater with a centered heat source, be able to withstand the wide wood fire burning right against the sidewalls ? Maybe it is better to extend the sides of the ash tray about 8 inches upright, to serve as a heat shield ?

Thanks for your input

 

[RonMar]

Renze
Yep, it might be much easier to convert the existing oil burner to wood than to build a new stove. Do you have any pictures of this oil heater you could post? Particularly looking into the opening to see what exactly you are talking about on the inside?

 

[Renze]

O.K. i will try to make a picture of the oil burner today, when i found the batteries of my digi camera... /forums/images/graemlins/smirk.gif

The heater has a big fan on top, pulling cold air from above, through the heat exchanger pipes, blowing it down out to the floor at about a foot off the ground.

There is another small radial blower with a 4" inlet and a 2.5" outlet, blowing fresh air into the heater's burn pit, where the oil also enters the heater.

The day before yesterday it was working like a dream, on a windy day. The last 2 days it was wind still, and i had no draft in the chimney. Because the blower blows air into the stove, it causes it to pressurise it and i had sore eyes from the smoke coming out of the poorly sealed door.

To prevent this i can do 3 things:
-Have the before mentioned blower suck the exhaust gases out of the stove, up in the chimney
-make my own radial blower fitted to the heaters exhaust opening, driven by an electrical motor on a long shaft to keep the motor away from the blower and hot exhaust gases in it
- use the existing blower to blow air through a venturi to create an artificial chimney draft with cold air...

I think the first option can be dropped right away..


Can anyone supply some info on venturi size and efficiency ?
The exhaust opening is i think 5 inch, and my chimney is 6 inch. The outlet of the blower is 2.5"

 

[Renze]

All right i've got my smoke problem fixed: due to an improperly installed chimney elbow piece, there was a leak from the heat exchanger part to the chimney, causing the blower to blow fresh air into the chimney pipe, smoke out the door /forums/images/graemlins/ooo.gif
I got it fixed with duct tape for as long as it lasts... /forums/images/graemlins/smirk.gif
Even burning a small PVC pipe as a test, will cause killing emissions outside, but no smell in the workshop at all... /forums/images/graemlins/smile.gif

I promise to post some pics of my modification plan which is to be carried out tomorrow.

 

[caddison]

Guy's keep in mind when building home made heating units that your insurance company may not be to crazy about the idea. Many times home made heating units will deem your shop ineligible. Just my 2 pennies worth!

 

[Captinjack]

I've heated my hunting cabin for the last 22 yrs. with the same 55 gal. barrel heater and have not replaced the stack nor the barrel. Or problem is not enough heat, but how to keep it turned down low enough! We use small chunks of wood rather than the full length logs we used to use before we installed insulation.

For a shop heater, I would use a water pipe system installed in the concrete base pad heated with any source that is cheapest. My buddies place is comfortable to work in with 40 degree floor.

I can't believe y'all need 1/4 plate when a simple 55 gallon drum works great and is as cheap as it gets.

 

[Farwell]

Captinjack,
I purchased the kit to make a double barrel stove and before I got around to building the stove I changed insurance companies. My new insurance company, ($400 a year cheaper than my old one) did a property inspection and stated that I could not have a wood burning stove in any of my buildings, if I did they would cancel my insurance and if I did and had a claim they would not honor the claim. The kit is still in its original boxes in my basement.
My neighbor uses a barrel stove and keeps his pole barn/work shop at 70 degrees all Winter long and works in shorts.
The barrel stove is a great way to heat.
Farwell

 

[Jagmandave]

A buddy of mine heats his 30' X 50' pole barn with a double barrel stove, he also has a hard time keeping it from getting too warm His has been in use over 10 years and both barrels look fine to me. he also has a squirrel cage blower on the floor to blow heat across the stove to help warm the barn up quickly.........

 

[RonMar]

I have decided that I am not going to put my old wood stove into my 24' X 24' garage/shop. I don't want to loose the floorspace it would occupy or cut a hole thru the roof and have to fit the new ceiling in around the flue pipe. Instead, I am going to make it into an external air heater by installing the stove in a metal locker outside the shop(about 3' from the garage wall) with it's own free standing chimny. I will run an airduct that draws air from under one of my workbenches and another duct from the top of the locker that returns warm air back thru the shop wall. I will use a large fan to move the air thru this heater. To the stove I will weld on heat exchanger fins and add some internal baffels in the locker to force the air all around the wood stove. This will also put the stove closer to the woodshed and will keep all the wood mess out of the shop.