Man Joe, your an encyclapedia on HVAC. Reckon you earned your name sir!

Thanks for sharing the knowledge, an poking fun at the Canucks..tho Jord will blame me for it. Thanks to the OP to for the thread, never herd of such a thing as r-18. I can add this to my random facts to annoy friends an family with.

Sirscrapalot - Look Ma, no derailing!