I am reading about "direct vent" natural gas heaters which use a hole through the wall for intake air and exhaust. And some seem to be "staged" in that they will have a lower burner/fan amount for say warmer days, yet have the burner on full blast and fan on full blast when needed for very cold days.
And these seem to be *very* efficient, energy saving, etc.
I am looking at a "7 stage" Rinnai RHFE 1004FA 38,400 BTU Model...$1449.95
Is this the most energy efficient heater of this type?
Can this be installed under a window?
If buying on the internet, do I need a "U.S." model?
Also my electricity goes out briefly about once every two weeks (live in rural area). Will this unit work by keep its settings after a power outage?
Best price for U.S. model on internet?