Hi folks. I'm new here. I registered because I see some very good advice offered... and I need advice.
I live south of San Antonio, TX and summers are hot and humid here. We've had summers that reach 105+ degrees every day for many months at a time. I can no longer take the heat due to health issues so cooling is, by far, my major concern. I want heat pumps for simplicity of installation and ease of operation. It seldom gets below 30 degrees here in the dead of winter, BTW.
I'm having built a small two-story 1100 ft2 home. It's well insulated with a metal roof. The windows all have awnings to keep direct sun out. I want to install several mini-split heat pump systems. I DON'T WANT ANY DUCT WORK. I really don't want any multi-zone systems BUT I'm open to suggestions. I like flexibility and overkill... if one system fails I'll still have the others working... I can shut off all but one or two systems if I choose.
AREAS TO COOL: <proposed BTU size>
living room = 3500 ft3: <18K-24K BTU?><or two smaller units?>
(above has kitchen included but I don't cook much)
first floor bath = 800 ft3: <9K BTU?>
first floor bedroom = 1000 ft3: <9K BTU?>
(above might have washer/dryer also)
second floor open space = 1500 ft3
(above also needs to partially cool a 500 ft3 closet via passive vents plus a 500 ft3 half bath -no shower or tub): <12K BTU?>
second floor bedroom = 1800 ft3: <12K BTU?>
I realize these systems are probably too large for each space but my experience here is that overkill is FAR preferable to underkill. I think these will work if I buy inverter style units. Also, I know you're aware, no ductless systems smaller than 9K Btu are available. I might even opt for 24K BTU for the living room. Another option is to install two units on opposite sides of the living room... either 2x 9K BTU or 2x 12K BTU or 1x 9K BTU plus 1x 12k BTU and swap/combine as needed. This offers more control in the largest living space... I can set one unit 2-3 degrees warmer to only start if the first unit can't quite do the job.
I'm very open to suggestions because I know nothing about HVAC systems. I only know what my experiences tell me which is buy a system that's 150-200 percent larger than most installers recommend. I need a very cool environment.
ETA: I could probably get by with just a high-volume exhaust fan in the downstairs full bath (no dedicated heat pump)... dunno.