We have a one story house. It’s 1040 square feet. Our central air unit, which was about 20 years old, finally broke. We’ve been told it’ll be about $4,000 to replace it and that amount of money simply isn’t in the budget right now. I was wondering if maybe putting a mobile air conditioner at one end of the house and another one at the other end would efficiently cool most of the house? I thought mobile units might work better than window units because we have casement windows, and I know casement window units are also pretty pricey. All 3 bedrooms have doors but the living room has an open entryway into the kitchen, so there wouldn’t really be a way to close off the air between the living room and kitchen that I can think of. I even thought maybe just getting an air conditioner with a super high BTU, but again, what’s the point if higher BTU doesn’t translate to coverage of more square feet. Any advice would be greatly appreciated. Thanks.
In terms of just "can two mobile A/Cs cool a 1000 sqft area", yes, they certainly can. I lived in a similar-sized apartment for a couple years and did just that -- one unit, a monster mobile A/C, was in the living room and cooled the living room, dining room, office, and kitchen; the other was in our bedroom and cooled just the bedroom.
However, you mentioned that you have three bedrooms -- if those are occupied, I assume the occupants will want to close their doors at night. At which point, the cool air won't be able to get into the bedrooms.
I would carefully consider if the investment you'll have to make into the mobile A/Cs is worth the trade-offs (especially the noise, as Jeffrey commented), considering that you'll eventually want to fix the central air anyway.