The size of any air conditioner is limited by several factors. Voltage is one such factor. When looking for high BTU AC units, we usually want to figure out this:
Which is the largest air conditioner for 110 or 115 volts?
Most electrical grids provide 110V, 115V, and 120V voltage by default. What’s the maximum BTU air conditioner we can plug into those voltages?
First, let’s look at the BTU ranges of the most common types of air purifiers that can still run on 110V:
- Portable air conditioners: 8,000 – 14,000 BTU running on 110-120V.
- Window air conditioners: 5,000 – 15,000 BTU running on 110-120V.
- Mini-split air conditioners: 9,000 – 12,000 BTU running on 110-120V.
Let’s look at each type separately and provide examples of the highest BTU AC units for each:
Highest BTU 110V Portable Air Conditioners (2 Examples)
Almost all portable air purifiers run on 110V. They can generate anywhere from 8,000 BTU to 14,000 BTU. You can easily move them around (unlike most other AC units).
The ones with the highest BTU output – 14,000 BTU – are powered by 1,300 to 2,000 Watts. We’re talking 10-18 amps.
Here are 2 examples of the 110V portable air conditioners with the largest BTU output:
#1 Whynter ARC-14S 14,000 BTU Dual Hose (Best Unit With Highest Energy-Efficiency)

Whynter ARC-14S is the best example of the highest 110V portable air conditioner. It can be hooked up to any 110V outlet. It’s powered by 1,300W and 11.6A. You can buy it here:
You will find it at the top of the list of the best portable air conditioners.
#2 Black + Decker BPACT14WT (Classic Large BTU 110V Portable AC Unit)

Black + Decker BPACT14WT is a classic version of a portable air conditioner that can achieve the highest 14,000 BTU cooling output while running on 110V. You can get it here:
Check Black + Decker BPACT14WT
Window AC Units With Highest BTU Running On 110V (1 Example)
Window air conditioners are installed on a window sill. They are less portable than portable air conditioners but they too can use the 110V outlets.
The highest BTU a 110V window air conditioner can generate is 15,000 BTU (you will find one example of a 15,000 BTU 110V window AC below).
Window air purifiers can achieve almost 30,000 BTU cooling output if hooked up to 230V. For example, LG LW2516ER running on 230V has 24,500 BTU and Frigidaire FFRA2822U2 can even reach 28,000 BTU on 230V.
#1 Example: Emerson Quiet Kool EARC15RE1 (Highest 110V Window AC With 15,000 BTU)

Emerson Quiet Kool EARC15RE1 has a large 15,000 BTU cooling output, despite running on the standard 110V voltage. Because of the highest BTU at low voltage, it’s one of the most sought after window air conditioners:
Check Emerson Quiet Kool EARC15RE1
You can check some other window air conditioners here.
Highest BTU 110/120V Mini Split AC Units (2 Examples)
Mini-splits are the most popular split-system air conditioners. The outdoor generator is connected to 1 or several indoor air handlers. 110V mini splits are usually 1-zone mini-split air conditioners.
Running on 110/120V, they can generate a maximum of 12,000 BTU cooling power.
Here are 2 examples of the highest BTU mini-splits running on 110/120V:
#1 MRCOOL – DIY-12-HP-115B25 DIY (Highest 12,000 BTU Mini Split With Highest SEER Rating)

MRCOOL – DIY-12-HP-115B25 DIY is an exceptional machine. Running on 110V, it can generate the largest 12,000 BTU cooling output. Additionally, it works as a heat pump and can provide 12,000 BTU of heating power in the winter. You can check it here:
Check MRCOOL – DIY-12-HP-115B25 DIY
Specific reviews of MRCOOL DIY air conditioners are found here.
#2 Pioneer WYS012A-19 (Affordable Large BTU 110V Mini Split Heat Pump)

Pioneer WYS012A-19 can, running on 110V, provide a large 12,000 BTU cooling power in the summer and 12,000 BTU heating power in the winter. You can get it here:
You can check the list of the best mini-split air conditioners here.
110V voltage can generate quite a lot of BTU output. 110V BTU, together with about 10-15 amps, can generate up to 15,000 BTU in window air conditioners. To power the biggest window AC units, with 24,000 BTU cooling output, you’ll need
The most popular mini-splits can reach a maximum of 12,000 BTU running on 110V. The portable air conditioners also get a decent cooling capacity; the largest at 110V is 14,000 BTU.
If you have any questions regarding the high capacity 110V air conditioners, you can pose them in the comments below.
Hi there. Such good information, thank you! Do I need to add higher amperage for starting up or would a 20 amp (in general) be sufficient for 12,000 btu
Hello Todd, 20 amp would be sufficient for 12,000 BTU units. The initial current surge will most likely be less than 20 amps.
I ordered a Honeywell portable air conditioner 15000 btu can my 110 volt house handle it
Hello Lucille, check the specification sheet, the voltage is listed there. If it would be an 18,000 BTU unit, you would most certainly have to use 220/240V. With a 15,000 BTU unit, there is a good chance that it still runs on 110V.
Are there any 12,000 BTU mini splits that use two cassettes? Or are they all just one? If you were to use a portable generator to power a mini split, can a Honda 2000 power a 12,000 BTU mini split?
Hello Rick, you have two 12,000 BTU cassette dual-zone AC units, for a total of 24,000 BTU of cooling output. There are no 6,000 BTU + 6,000 BTU units. The smallest mini split units are 9,000 BTU.
For the generator, you should look into running and, more importantly, peak wattage. A 12,000 BTU mini split with an EER rating of 10 will have a 1,200W running wattage. The Honda 2000 can handle that, the problem is the peak wattage; which can spike over 2,000W quite easily and the Honda 2000 won’t be able to start such an AC. If it helps, you can check our post about how to adequately size a generator in 3 simple steps here.
Hello. I currently have a 12,000 BTU portable AC unit “cooling” a 12′ x 18′ free standing tiny house/studio. I put the word cooling in quotes because it cannot cool this small space. The studio is well insulated but the portable AC just can’t keep with the heat beginning around May. I am really disappointed in the portable unit. I am looking for alternatives and at first considered a 12,000-18,000 BTU DIY mini split system. But will I just get the same results? i.e. is there something inherently more powerful in the mini split design so that a similarly sized unit (12,000 BTU for example) would cool better than my 12,000 BTU portable AC unit?
Hello David, essentially, a 12,000 BTU cooling output is enough for a 12×18 studio. Now, the problem might be with the device, of course. Your portable AC probably has a specified cooling output of 12,000 BTU; it might be that the unit is just not capable to reach its specified BTU maximum or that warm air is leaking in from an open window (improperly mounting a portable AC hose through a window can usually have the same effect). It might also be that the unit is producing 12,000 BTU but is a single-hose unit, creating negative pressure indoors, and sucking the warm air in.
With mini split, you do rid yourself of some of these problems. You don’t have pressure imbalance, no window openings to fill, and so on. In general, mini splits are considered the best AC unit type you can get – quiet, high SEER ratings, reliable. In any case, you would probably need a 12,000 BTU unit; an 18,000 BTU would be overkill. If you need some suggestions, you can check these DIY mini splits units; MrCool is considered the best brand for DIYs. Hope this helps.