I have an out door wood burning water heater that heats water to heat the house and also provides hot water for showers etc. Cutting and spliting wood has gotten old. I would like to convert it to burn waste motor oil. I like the method that I see Eric is using for the burner. I contacted Jesse to get some nozzles on the way when the subject of nozzle size came up. The fire box on my water heater is no less that 3.5 feet square. Has anyone here tried this ??? I am looking for advise as to what size nozzle I should try first, As well any thought on if I should decrease the size of the fire box, (Raising the bottom).

Shouldn’t we be talking about cubic feet? Oh, and by the way, if anyone wants to post a diagram/pics of outside furnaces this would be of interest to me, probably others. I swear one day soon, I’m going to start organizing my thoughts on this and decide my route. Right now I have a gas source furnace so I have a considerable conversion to do.

Thanks for your reply to my msg,I am a bit confused by it. Do you need / want to know how to figure out the cubic feet of a 3.5 foot square box?

I think it was just a misunderstanding between square feet and feet square.

It’s more of a general question for the group. I’ll basically be building a whole new system in 2005 so this is all going in the “research file”. It just seemed to me that we should be talking about cubic feet of a combustion chamber since we are in 3 dimensions and not square feet. I’m wondering what the minimum cubic foot size would be.

Now that the size of the combustion box is known, I’d say you probably need a 609-11 for that size chamber. Is there another Koal-wool insert in that 3.5 square box? I’m not an expert on chambers, so there may be more to it than just that size. I hope some tech guys can weight in here. Doesn’t the size of the flue come into play?

I want to say the flue is 8 inch dia. Length is about 4 feet from the top of the unit. Above the fire box / combustion chamber are the water tanks, They are connected by pipes, 2 tanks, one front & one back. The space between the tanks is about 12 inches, The flue is above / in this area. My unit uses a sheet metal tray to catch soot and stuff from the wood and to slow the heat down. It is mounted between the tanks with an open area on both the left and RH side of the metal tray for the Flue. Due to the size of the Oil furnace unit, I will mount the blower / nozzle unit in the existing Wood / fire box door, It is about 20 ~ 24 inches below the water tanks, to the bottom of the door. My other choice is the ash door below the fire box area.

Mounting the unit here would require it to be pointed down towards the ground, with out turning the coil/blower motor / nozzle unit upside down. I have 2 blower / nozzle units now, 1 Beckett and an off brand, for a quick / temp fix I am in the process of installing one unit without conversion to run Heating oil, while I get the other unit converted to burn Alt fuels. I figure that regardless, this Wood burning unit will not be as Eff% as a newer boiler but I have to work with what I have. (for now) From what I can tell from the past messages, Most have their converted units running inside, Using room temp air as the supply for their Blower fan air. As my project is out side, I wonder if the colder air being drawn in by the blower fan will require me to increase the temp of the compressed air and or Oil. I welcome any thoughts regarding this concern.

If you are going to be using the blower motor with the siphon nozzle setup, then yes, I think that the cold air being sucked in has to be considered into the equation. But if you have a housing around the burner and the air is being pulled from inside the housing where it’s warmed up a little then that may work as long as the compressed air and wvo are very, very hot.   I believe this is the first time we’ve discussed having a Beckett running outside so we may be in a new area as far as experimentation goes.