Wood/oil burner duct servo?

chopped · Dec 13, 2013

Hello. Yes Im back with another stupid question.
Here is my situation. I have both a wood furnace and a oil burner hooked up for forced hot air.
The wood duct is straight run and the oil comes in at an angle. Presently I have a 'damper' in each and choose which to open and also to close during operation.
they open manually with a homemade lever. I would like to somehow 'cheaply' have them so one could open and stay open when in operation.Basically when I switch the power for the oil then it would open the damper for circulation.
Anything Ive found is more money than id like to spend. And im looking for something basic. Im just not sure what to look for , what names or phrases to use.
Any help would be appreciated.

Loadstar · Dec 13, 2013

Here are some keywords you might want to look up to make it work.

-actuator
-damper actuator
-damper linkage
-spring return damper actuator
-24v R.I.B. (relay in box)

arlen4720 · Dec 13, 2013

I'll attach a cut sheet form the company I work for (Johnson Controls). The M9208 has 70 inch pounds of torque. Thats about the smallest one we have. Kele company would probably be the best bet for buying one or two. They have the RIB relays also if you need one. If you are just going to have a selector switch, you may want to use 120 volt actuators. The possibilities are endless as far as the different degrees of automation. I'm guessing that the actuators would go for around 175 bucks through a distributor.
You can see from the cut sheet that this actuator is designed to apply torque to a pin sticking out of the duct. It's probably the easiest way to go.

chopped · Dec 13, 2013

Thanks for the ideas. Its all in the wording.

hr3 · Dec 13, 2013

I have pretty much the same setup and use a 10" backflow damper much like this ,, Fantech RSK 10 Backdraft Damper 10" Duct: Amazon.com: Industrial & Scientific

SPIKER · Dec 13, 2013

I would go to the Junk Yard and buy a couple 12 VDC Door Lock Actuators out of some junker BIG OLDER Fords Lincoln as they seem to have very strong linear actuators that are powered UP and DOWN mechanical versions. I have a few out of my old Thunder Bird that takes about as much to hold them as you could think with a stroke that is 2~4"...

Mark

arlen4720 · Dec 13, 2013

hr3 said:
I have pretty much the same setup and use a 10" backflow damper much like this ,, Fantech RSK 10 Backdraft Damper 10" Duct: Amazon.com: Industrial & Scientific

I think backdraft dampers are a fantastic idea. But as an electrician, you shouldn't be suggesting non electrical solutions; it's bad for business.:laughing:

hr3 · Dec 14, 2013

arlen4720 said:
I think backdraft dampers are a fantastic idea. But as an electrician, you shouldn't be suggesting non electrical solutions; it's bad for business.:laughing:

My heating system is complicated enough already,, Warm air with 10 zones for the heat through a Mastertral Mark X and a powered dump zone just for the workshop,, along with a 2 zone warm air solar setup,, and yes the wood furnace with and electronic readout in the living room so I can monitor the stack temp from up stairs,,, The wood furnace I wanted to use the KISS method on just in case neither of my generators were to start while I'm not home..

jwmorris · Dec 15, 2013

If you know a guy that does pool service see about getting an old electric control valve. You can adjust how much rotation they have with internal limit switches. I have my air compressors set up with these, operating ball valves, to shut off the air remotely. Jandy is the trade name on mine.

lamanated · Dec 16, 2013

look up Oil Vent Damper by field controls,, Thats what I have

Midniteoyl · Dec 16, 2013

The simple butterfly type or spring loaded backdraft dampers work and are cheap, assuming two air handlers which is what i think you described...

But, if you have rectangular ducting, and the oil burner comes in vertically from the bottom, a simple flapper valve placed over the duct angling in would do the same. A simple piece of sheet metal covering the entrance, hinged in the rear. When the air from the oil burner is moving through it, it will be pushed 'up', when not, it will fall back down due to gravity. You can line the flapper with foam to seal and quiet it... Simple.

If the duct comes in hortizonally, a very light spring could take the place of gravity, though prolly not needed as the pressure would 'hold' it shut.

edit: picture to give idea, though I would make the flapper big enough to touch the other side of the dict at an angle so as to not worry about it 'making a seal' against the other hole.

hr3 · Jan 3, 2014

Chopped ,, How did your duct work and damper work out??? I have an add on wood furnace too and love it,, 20 below outside last night and nice and warm this morning inside,,

chopped · Jan 4, 2014

Well i bought two of these.
Johnson Controls M9210 Bac 3 Spring Return Damper Actuator 120V w Switches | eBay
Very Heavy Duty.. Haven't gotten them installed quite yet but I tested them and they work fine. I have a wood furnace and also an oil furnace into the same hot air trunk.And for 30 years have had to manually turn on and off the dampers.These will allow them to work independently .I plan to wire them each into the blower fan circuit so they will open and spring closed with the fan on and off.On the oil it wont cycle to often as it tends to blow pretty steady. but the wood/coal furnace it will usually cycle (blow) many times.So i hope the modual lasts. But for this price I think it will . Only time will tell.
I had a 'woodchuck' furnace new in 1980 and it worked fine but didnt have the fan on the intake.so it was alot of tending to it.
In 1985 I bought a NEW woodfurnace for 200 bucks.:thumbsup::thumbsup:9it was one someone bought in panic in the original energy crisis)(1970's).It is a slight bit undersized for my house but I began using that one 15 years ago. and has worked fine for me. the original i sold ..
Wish i still had it back.
Anyways the damper mods are well worth the money. I saw a few that were smaller, and I liked them but I would have had to get a transformer and the price would come close to what I paid for these.(120 volt)..