i built a large chest smoker

[txg derwood57]

so I have built my first propane chest smoker and I am in search of a blower to move the heat.

 

[bill1]

so do you want a high-temperature blower that mounts inside the chest so the inlet to the blower is inside hot smoky air and the outlet is the same hot smoky air but moving faster across the meet?  (Increased circulation WITHIN the smoker)  Or a low-temp blower mounted outside that intakes cold air, lowers the smoker temperature somewhat, but increases the smoker's "draft"?  (Increased circulation THROUGH the smoker.)  

Do you use wood or chips or rely totally on the burning propane for smoke flavor?   

 

[txg derwood57]

i use wood chip for the smoke. I think I need a low temp fan because I'm all ready burning too hot as it is 200 degrees with the burners on low. The chest is 48in tall 42in wide 28in deep. I made it manly for jurky and summer sausage. so the temp needs to be at around 160 to 175

 

[bill1]

I'd bring in a 1/2" EMT conduit into the very bottom, use a couple tees to bend it up the 4' side.  (That will work like the standard air intakes you typically see on ugly drum smokers.)  You may find you get quite a bit of natural "draw" just using that approach.

Since cold air is flowing as a coolant, I think it's ok to use galvanized EMT the whole way but if you're uneasy about it, make the last few inches into the chest a black iron nipple and you'll be fine.  (Note 1/2" EMT can be weakly threaded with a 1/2 NPT pipe die so it's the cheapest metal pipe you can buy.)

Get a couple conduit clamps to mount it permanently to your chest smoker if you like it.  

If you want more flow, I'd use an air mattress inflator blower.  They're about $13 at Walmart.  That may be TOO much flow so consider wiring in a typical 600watt light dimmer in the circuit.  I've found you can really slow those blowers down that way.   Just make sure you mount it up high so you can use the gravity push of cold air up high to help the flow.  If you mount it down low you won't be able to slow down the flow with an SCR controller (dimmer) nearly as well.  

Of course this is going to make you burn more smoke wood/pellets as well, but nothing's free.  

Speaking of which, the mod I'm describing above is ~$20 in parts, so if it works, you might buy some spares of the electrical parts...you don't want to ruin a big party and $100 worth of meat over a failed $13 blower.  

But if you're just trying to get less heat/temperature, can't you just further adjust down your propane flow?  Move the burner down lower away from the input to the chest so more heat is lost out the side?  Put in a flame diverter???

It's the typical situation...the electric guys always seek MORE heat and the gas guys look for less!