Best cfm fan AUF (OTE)

[Hunt4sap]

Would like to know a good cfm for my oil tank evaporator?

My feeder tube is 2" EMT cap welded on end inside fire box and stopped it 8" before door and has 12- 3/8" holes per sq.foot of my firebox( drilled one row TDC, others are at 10 o'clock and 2 o'clock)
Looking for experience specific to OTE because that's what I have built for this year...

[mol1jb]

You can use just about any cfm fan as long as you have something to regulate the flow. Simplest would be either 2inch ball valve or blast gate in between your fan and OTE.

[Super Sapper]

You will be restricted on CFM's by the 2 inch pipe so you will not get the rated CFM of a low pressure blower if it is rated higher than what can go through your pipe. I am not sure what the CFM is that you can get through the 2 inch pipe but any blower higher than that will not add any more air. It may be enough to max out your rig but will help a lot even if it isn't maxed out.

[RileySugarbush]

I agree with Sapper. Connect your blower with a tube that has at least as much cross sectional area as the blower outlet. Any low pressure blower will help, but shoot for over 200CFM to up to 300 and adjust it by blocking the blower inlet (my preference) or outlet with a blast gate. No need for the holes in the tube. Just blow into the area under the grate, which should be enclosed, and let the air flow up through the fire.

[Hunt4sap]

Ok, holes are already drilled in it so we'll give it a shot this year and see how it performs...

[Haynes Forest Products]

Some blowers have high CFM ratings BUT don't have the pressure to get the flow thru the smaller restrictive piping. A box fan can move a lot of air but restrict it into a 3" pipe and your screwed.

[phil-t]

The cfm has been covered. I had a diy setup, like you describe, on my half-pint (the tube with holes, under the grates). I ended up doing what was recommended by Riley, dumping the air just inside the firebox, under the grates. Worked way better than the tube full of holes. I also prefer the "damper" on the inlet of the fan, but the blast gate will work equally as well. It won't take long to get into a firing routine that works well and know where the air regulation needs to be.

[SyncroScott]

Just a helpful tip here if you haven't found a blower for your setup yet: The exact same 2" blower they sell on some pro sites for $300+ for hobby-sized evaporators (Half Pint, etc) is only about $65 on Amazon ("Dayton 1TDP3", 70cfm). I found there are also very similar priced/sized units on there that range from 40 to 150cfm. Amazon also has speed controls for some blowers for under $20 too.

[maple flats]

The tube with holes will only work well if connected to a high pressure blower. Unless you can find an old oil burner pump (those have a HP blower) I suggest you just remove the 2" tube and blow in under the grates, block off the front 6" to push the air farther back from the fill door. If however you find a HP blower it will work well. The price of a HP blower will be out of practical reach on this size evaporator unless you can find an old oil burner blower free or real cheap.

[Tater]

I used a "bounce house" blower for the AOF/AUF blower for my 2x6. Idk if you want that much air for AUF in an OTE, as it will effectively blow a lot of wood out the chimney. I purchased my blower from ebay for less than $50.

[Cjadamec]

The blowers from large inflatable lawn ornaments make decent AOF blowers in a pinch and can be had pretty cheap if you keep an eye out for them.