GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Inverter vs. regular minisplit vs. window AC unit

Atgblue1 | Posted in Energy Efficiency and Durability on

I have a summer house in Monterrey Mexico, 150 miles south of US-Mexican border.

Average summer temperatures are 32-38 celsius, with peaks of 42-44, and lows of 25-30 celsius.

The area to be cooled is the top 2nd floor. The house was built in 1960, with mexican cinder blocks (not as dense as american). There is 0 insulation. The ceiling is like tic tac toe squares of concrete beams with Styrofoam filling the gaps, covered with 2 inches of concrete on top. The roof has a type of liquid water-proofing mopped over the top every 3-4 years.
Sun hits direct all day long, either side, or roof.

So question, is should I get inverter minisplit, or regular one? And should I buy the 2 ton or 1.5 ton? We have 220 and 110 volt setup.

I was wondering, because inverters are supposed to be more efficient at reaching set temp and maintaining it long term.
But this house, usually isn’t left on all day and never all night (only individual room ac’s on at night)
So my logic is that it will usually not have much time to maintain the temperature and get use out of the inverter abilities like we would if we left it on all the time and it had a lot of time on the set temperature.
So is it still more efficient to get inverter if ac is gonna be on aproximately 6-10 hours per day (occasionally 12 hours)
during summer?

Also, if the 2 ton was a bit too big for the room, I’ve read Short cycling can decrease life of AC, can not this be remedies by the AC running on the lower settings?

Thanks for any help!

Ps: I’ve never known a minisplit be as strong and efficient and fast at Cooling, as window units of the same btu’s. Is that just me or a known fact?

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. GBA Editor
    Martin Holladay | | #1

    First of all, can you tell us your name?

    The first step in designing any cooling system is to determine the design cooling load. That calculation require information like window sizes, window orientation, window specifications, window shading, and building dimensions.

    In general, if the equipment is properly sized, any of the various types of equipment you have listed can cool your space. In general, minisplits with inverters are more efficient, but also more expensive to purchase, than simpler equipment -- so the equipment decision depends partly on your budget.

  2. Atgblue1 | | #2

    My name is John Alvarado. I guess I figured a proper calculation wouldn't work as the house is not insulated at all as in america, its not a 24/7 cooling system, and the heat is extreme.

    The room is 16 feet wide by 30 feet long. Aprox 9-10 feet celing (starts low on south side and slants upwards to 10 feet)

    There is one large window 78in tall by 59in wide, single pane glass, tinted, on the east side which is in direct clear path of 9:00am sunrise. (Blocled by house across street until then)

    There are 2 american double pane (with gap inside) windows (also its not glass, but that plastic type) on the west side, but this side only gets sun about 2 hours per day due to a tree and building blocking most of the sun.

    The roof is in unobstructed view of the sun all day long.

    The north side of the room is next to adjoining bedrooms aprox 10x10 feet, so no sun from that direction.

    The south side has nothing near it or blocking light/sun.

    I have the budget for whichever unit, inverter or standard, and either size btu's. If its worth it, I'll buy whatever, i just didnt want to buy something that was complete overkill unless it would be efficient and I'd get use out of it
    I read that the savings from an inverter would take years to pay back in energy savings and so best was to go for standard. This same source argued that inverter repair was more frequent and more costly.
    Does anyone here have experience in that or a brand to avoid or recommends?

    I lean more towards just going big and buying a 2 ton inverter and just running it on low settings if it works too well so as to short cycle etc.


  3. GBA Editor
    Martin Holladay | | #3

    The controlling factor in your case (buying an air conditioner in Mexico) may indeed be one of the points you raised -- "repairs may be more costly." Air conditioners with inverters aren't really less reliable, as far as I know, than air conditioners without inverters, but if maintenance workers in your corner of Mexico aren't very familiar with them, it may be worth avoiding them.

  4. Atgblue1 | | #4

    Yeah that makes sense. I'll look into that first and then just go with solething and see how it works out


Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |