Pre-heater sizing question

[Bucket Head]

Hi Guy's,

I'm drawing up plan's for my homemade hood and I have a pre-heater question.

What size copper pipe, and how many feet of it, should I have for a 2.5x6' rig? It has a four foot flue pan.

What do you guy's have in your evaporator's that are close to the size of mine?

Thank's,
Steve

[Fred Henderson]

I used 1 1/4" for the header and 3/4" for the laterals. My 3/4 is fin tube radiation tube like you would use in a house for heating, just get as much in as you can.