Great thread and conversation - thanks to all for bringing it up and contributing. My vested interest is one who is 1) getting a 1# natural gas sample roaster from the USRC group buy and 2) intending to get my city code official's approval.
It sounds like we have many who haven't pursued code approval and I pass
no judgement on your choice. But I, like B|Java, want coverage if something bad happens...I don't want my insurer rejecting my claim because I had an "illegal" operation going in my basement. (Not talking about moonshine or meth
)
I think code-approved use of "commercial" roasting units in a residential (non-commercial) application is still cutting edge or plowing new ground. At least, that's the way it sounds to me as I talk to my city code people or others in larger cities who've gone through this. That's at least mostly true if you're venting directly out of your house, not up a chimney. If you are operating a business and not in your home, you're likely using a large(r) roaster and venting is pretty straightforward and certainly more costly. My code official is willing to work with me to get the job done achieving what we both want (safety) and what I prefer (least cost, not the big-buck Mercedes options). To get that approval they are looking for proof that what I propose is safe.
For clarity I'm going to define what the options look like, most already directly or indirectly referred to in this thread already, from cheapest to priciest:
1. First, there are all the cheap routes that are probably not good choices - plastic dryer ducting, etc..
2. Next there is single-wall rigid and flexible galvanized steel or stainless.
3. There is what is called Type-B flue venting. It's double-walled, rigid galvanized steel - some have an aluminum liner, but has an air space between the walls for insulation. It will remain hot to the touch so it needs 1†clearance (air space) to any combustible materials like floor joists, etc. The cost is reasonable as compared to...
4. Finally there is Class A venting that comes in double or triple walled stainless pipe. This is the Mercedes, costly route. It's lined with some sort of thermal woven material. It's what Steve Green notes most manufacturers recommend -- if they say anything -- to keep their legal butts covered. (Bill Kennedy at San Franciscan told me they "recommend" this - referring to this one
http://bit.ly/WTjsBH).
I'm hoping to use #3 Type B. I know that code officials like to talk about/look for UL listings for appliances and materials - it's the safe haven for them. Type B typically says "Use for venting listed natural gas or liquid propane Category I, draft hood appliances, or appliances that have been specifically tested and listed to use Type B Gas Vent. The appliances listed typically use Type B Gas Vent systems, but not always: Furnaces, Water Heaters, Boilers, Room Heaters, Decorative Gas Appliances, and Unit Heaters." USRC is quick to point out that their roasters "are not appliances" - which has definitional meaning to them, is lost on me, but not lost on my code people.
Having said all of that, has anyone had code approval of your home install for a natural gas roaster? I'd like to know what you used. That's especially the case if it's direct vented outside (not chimney) and Type B. If I can get pics and a referral so my code peeps can talk to your code peeps, I'll be a happy camper!