Any Excel guru's with knowledge of how to calculate the cost to operate out there?
I'm building an Op cost xls, but my results so far are way off those of http://www.hvacopcost.com/
I'd be grateful for any pointers. And advice on how to factor savings from a variable speed A/C, and Furnace.
It looks like .xls attachments aren't supported here, so PM me and I'll email it to anyone who wants to give it a crack.