Quick wood burner & foundry Q's

[monkeymark]

|Thought id put these 2 questions into one as they should be short ones.

Firstly. The wood burner I intend to make will have a second air intake, one of the pre heated ones for gas burn. Just been given a stainless steel diffuser thing from a combi boiler. Would it make a good diffuser for the pre-heated air?

Secondly. I know those making foundries use hair driers. Is this just because its easy or because the air needs heating too? And is the more airflow the better?
Ive got a few fans id prefer to use before a hair drier from the likes of ovens and small air handling units but obviously wont pre heat the air.

Cheers, Mark

 

[brightspark]

if your making a half decent furnace u could do with a blower simlar to a bouncy castle .u need to regulate the airflow if your going to run it on coke either with a gate valve or move it further away from the furnace

 

[Maker]

I think cold air is slightly more efficient because gasses expand when they're warmer which would mean your getting slightly less oxygen. It's probably so slight you couldn't even measure it but your better off having cold air simply because it costs less to run. People just use hair-dryers for the convenience of not buying and wiring up fans.

 

[monkeymark]

Ah excellent that's great. The 230v fan I have from a air handling unit puts quite a bit of air out. Not as much as a bouncy castle fan but probably not far off. It also has a nice premade flange too :-)

 

[wookie]

Do they not just use the hair dryer but on the cold setting ?

 

[Maker]

Do they not just use the hair dryer but on the cold setting ?

I think so, that's what I'm gonna do when I can fire up my forge.

 

[pedrobedro]

If you're just doing a bit of forging you don't actually need that much air, a hairdryer will easily supply sufficient to heat steel to red heat.

 

[brightspark]

If you're just doing a bit of forging you don't actually need that much air, a hairdryer will easily supply sufficient to heat steel to red heat.

i thought it said foundry =furnace not a forge