I am adding a 30x16 family room addition and 20x20 master bedroom suite.
We keep our bedroom very cool, even in Winter, but prefer a warmer family/tv room. We are in Ohio, so winter can get cold and I understand that heat pumps are not effective at 18 degrees or less, so my thought was to supplement with a vent free gas fireplace for colder days (99% effficient). Essentially we are adding two "zones" to heat/cool, with each zone having it's own independent unit. has anyone had experience with the Mr. Slim products, and has it been favorable?
There are some byproducts from combustion with a vent-free unit. It consumes O2, and produces CO2 and H2O, with various other gasses, depending on how clean it burns and the exact composition of the gas feeding it. In a tight house, it's not the greatest thing. A small one for atmosphere that doesn't run forever is another thing.
Important note - I'm not a pro
Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013
In your climate, heat pumps are of limited use, and most installations of a heat pump would have back up electric strip heat, which is not an option with the minis.
I would consider some heat sources ( other that ventless gas....don't like that idea at all!)