275 gallon fuel barrel arch forced air question.

[eddy6963]

Hello, this is my first post. I may not have all the proper terminology yet, as this next year will be my first full season, and first season running a arch evaporator and not my highly efficient turkey friers. So my question is for those of you who have an arch like this, how many pipes do you run for your forced air and what size holes do you drill and how many? Any advice on how you have done your arch, photos definitely help.

[maple flats]

For air under fire it is usually just 1 pipe, powered by a squirrel cage blower. To control the air it's easiest to just use a flat piece of tin as a sliding door over the air inlet to the blower.
For Air over fire (AOF), you need a high pressure blower. Likely not in the budget or practical on a oil tank arch, but something to definately worth studying for future improvements if you get into this in a bigger way. However, if your 275 gal tank made arch is going to get all the efficiency it deserves to get AOF. With that you add air from the high pressure blower every 6" thru a nozzle all around the firebox at 6" below the pan(s). Do some reading for that. It greatly improves the efficiency of the burn, increases the boil without burning more wood, by mixing the high pressure air with the wood gases for more complete combustion.