Hello, I'm looking at replacing a old 70's ashley burner. My problem is I will be gone from 14 to 15 hours a day and often will have no coals when I return. I turn the auto damper down when I leave and as a result the stove puts out a lot of smoke which has caused my chimney to clog up quickly. I had a flue fire after I had cleaned it out only a month earlier. So I'm looking for a clean burning unit with a long burn time. Is a catalytic unit the only way to go? I was also looking for one with a nice window since the old ashley never had that option. I found a couple of units I would appreciate some feedback on and of course if anyone has any other units they like please let me know. The first stove is the appalachian 52bay. This unit claims a 15 or more hour burn time with a 77-90% efficiency. The firebox is 2.8 cu.ft The unit weighs 360 lbs. The second stove is a blaze king 1107. It claims a long burn of 40 hours with a 82.5% efficiency. The firebox is 4.32 cu.ft. It weighs in at 435 lbs. It also has a automatic thermostat. Speaking of the automatic thermostat why are they not a option on more stoves? Is there a problem with them? Thanks for any help.