"CBHvac" wrote in message
...

Hi,
Big cast iron thingy alright but at what efficiency?

50% or 60% maybe? Seen a few old oil units that MIGHT make it to the 50%
range...and have seen more than one Chrysler Airtemp gas unit that was
feeling frisky if it saw 65%....

so, let's say current furnace is 50% efficient.
let's say we get a 90% efficient one. how much less fuel is that per year?