fan to force air into homemade wood fired arch

[zachhll]

so we just got our new evaporator going and we have one small issue it is we need to force air into the fire to keep it hotter what type of fan can we use right now we are just using the blow side of a shop vac not what we want to do and really noisy. here is a pic of what we are working with 7074

[cmstearns]

i just bought a 4" heating duct fan from home depot for 30$ i havent tryed it yet but it should work

[aws]

If the pipe under your door is your only air inlet you may want to try adding more holes under your grate for air. I have a similar oil tank set up, and as we speak it is glowing red (can't tell its' red during day light hours but at night, Wow) without any forced air. I have lots of 1" holes drilled under the grate and leave the door open a crack. It gets unbelievably hot this way. Of course small dry wood is essential as well. I also wanted to install a blower for a while, but I am happy to have one less thing to take care of and it's quieter this way. Hope this helps.

[jputney]

I use a blower off of a gas fired high efficiency furnace. The blower that is used for the firebox. Find someone that scraps furnaces or your local furnace guy and get one off a junk furnace for little or nothing. I have mine on a dimmer switch so I can regulate the speed. Works great.

[bowhunter]

I agree on the modifications to the grate. I have a Leader half pint which has a 24 x 33 inch pan. This is my first year and I was also considering a blower I wasn't getting a very good boil rate, but after reading this forum and doing some experimenting I've decided not to add a blower for now. The grate is made of 2 inch angle iron spaced at about 1/2 inch apart. When the unit was bricked up per Leader's instructions it left a big gap at the front near the door so that air was bypassing the grate directly up into the arch. I closed this open space off with half fire brick and added 3 ft to my stack which is now 12 feet. I also changed the way I fired the unit. I went to really small wood (no bigger than your wrist ) and I stack the wood on the grate log cabin style making sure most of the openings in the grate are open when I add wood(about every 5-10 minutes). I'm using wild cherry cut in January and after the arch gets hot the evaporator roars when I add 2-3 sticks of wood. The pan boils so hard it sometimes tough to keep it in the pan. The unit is pretty air tight, but adding the stack and making sure all the air passes through the grate along with small wood made a huge difference. I'm not sure I would get much benefit from a blower once I start using dry wood.

[MarkL]

Great advice. I have the half pint too and have used an old bathroom fan and some flexible dryer vent to blow air under the fire but I found it just used up my wood too quickly with no appreciable difference in rate of boil. I'm using softwood, stacked log cabin style, stoking frequently, and it's ripping all across the pan right now. Whoops, gotta go stoke while it's boiling!