How many btu for my 18x28

[oldno3fan]

Inside deminsions are 17x27 im looking to install mitsu mr slim cathedral ceilings are 12 at peak r 38 in ceiling r19 in walls

 

[justinjoyal]

Quick guess: 12k should be plenty.

 

[Jackfre]

Minot or Miami?

 

[oldno3fan]

minot or miami?

southern va

 

[Falcon67]

Minot or Miami?

Antarctic or Adelaide? Denver or Death Valley? We could run with this...

 

[Wizzard]

12K would possibly be to small. I've used an 18K in an insulated garage that is your dimensions and it works perfectly. The 12ft cathedral ceilings need to be taken into consideration. It is harder to over size an inverter unit since they can throttle way back to ~7k btu in that size range. I'd get a 15k Mitsu.