I am purchasing a ductless mini-split heat pump. I have had several estimates and in all cases the companies recommend a 12,000 or 15,000 BTU unit. Apparently the area I want to heat/cool falls just in the middle for their calculations. I have a 1,500 sq. ft. bungalow with a large open concept living room, dining room, kitchen and front entry which is where the head unit will be. Off the living room are 3 bedrooms (no hallways) 2 on one side and one on the other. I'm told that the 12,000 BTU unit is more than capable of heating the open area, which is my main concern, but if I want to also provide at least moderate heating to the bedrooms I would be best to go with the 15,000 BTU unit. There is less than $200 in cost between the two units. I have decided to go with a specific brand and here are the specs for both models.
The 12,000 BTU unit has a SEER of 25, an EER of 13.80 and an HSPF (Region 5) of 10.435.
The 15,000 BTU unit has a SEER of 21.5, an EER of 12.5 and an HSPF of 9.565. Both are Energy Star rated.
I know higher numbers are better, but how much better? I also know that bigger is not necessarily better but does it make sense given the information I have provided?
Thanks in advance!