forced air heater duct material

[stantale]

Hi All,

we just installed a toyoset forced air heater, and I'm looking for the right material to make the duct out of - I really don't like flexible aluminum dryer tube since it's so flimsy, on the other hand I don't know what kind of rubber/plastic to use because it gets really hot (haven't measured but too hot to touch near the heater.)

Any recommendations on tube type that will insulate enough and withstand the heat? It's around 3" I.D.

Engine exhaust material is a bit on the expensive side ;-)

[mitiempo]

Most heaters I am aware of come with duct material or have the proper ducting as an option. Sure Marine in Seattle has everything you need as well as great heater information - their specialty. Sure Marine

[MacGyverRI]

You could use some galvanized pipe (like stove pipe but used for ducts) along w/ some elbows and wrap that w/ the 1/2" or so duct fiberglass that comes on a roll.

They also make a commercial insulated flexible duct (used for cooling/heating) that has the foil on both inner and outer w/ fiberglass on the inside and a wire spiral for strength.

[mitiempo]

The proper ducting is available at the link I posted and anywhere that sells a forced air furnace for marine use.

A "MacGyver" type solution is only a good idea if the proper ducting is not available. Galvanized pipe?

[MacGyverRI]

Originally Posted by stantale

Engine exhaust material is a bit on the expensive side ;-)

I gave an alternative solution by the $15 a foot stainless flex was expensive statement....

He's probably gonna have a heart attack w/ the $40-50+? a foot (evidenced by "call for price")...

[mitiempo]

The proper ducting is not very expensive. The price list below is from Great Lakes Marine Specialties in Minneapolis. 90mm ducting is just over $5/ft and some other accessories are listed as well. These are for Webasto heaters. There is also 60 mm ducting at about $3.50/ft.

Best to deal with a heater specialist.