Cooling · Montana
How Much Does It Cost to Run a Portable Air Conditioner in Montana?
The short answer
A typical 1,200W portable air conditioner costs about $0.18 per hour to run in Montana, or $43.78 a month at 8 hours a day.
The estimate uses Montana’s average residential electricity price of 15.0¢/kWh from EIA (July 2026) — 18% below the national average.
Source: U.S. EIA, July 2026 data · Updated
Portable Air Conditioner cost by daily use in Montana
| Daily use | kWh/month | Per day | Per month | Per year |
|---|---|---|---|---|
| 1 hour/day | 36.5 | $0.18 | $5.47 | $65.66 |
| 2 hours/day | 73.0 | $0.36 | $10.94 | $131 |
| 4 hours/day | 146.0 | $0.72 | $21.89 | $263 |
| 8 hours/day | 292.0 | $1.44 | $43.78 | $525 |
| 12 hours/day | 438.0 | $2.16 | $65.66 | $788 |
| 24 hours/day | 876.1 | $4.32 | $131 | $1,576 |
Montana vs other states
At typical use, a portable air conditioner costs $525 a year in Montana — $1,157 less than in Hawaii and $79.54 more than in Louisiana.
Montana has the 14th-cheapest residential electricity of the 50 states and DC. Montana electricity rates · all states ranked
Electricity price trend in Montana
15.0¢/kWh in July 2026 — ▲ +5.0% from a year earlier.
How to lower the cost of running a portable air conditioner
A portable AC sits inside the room and vents hot air through a hose, which makes it convenient but less efficient than a window unit: some of the heat it removes leaks back in, and single-hose models pull warm outside air into the room. A common 10,000–12,000 BTU portable unit draws around 1,000–1,300W. Dual-hose models are more efficient in hot climates.
- Keep the exhaust hose as short and straight as possible, and insulate it if it gets hot.
- Choose a dual-hose model for rooms you cool every day.
- Close blinds on sun-facing windows during the hottest hours.
- Summers in Montana are relatively mild, so cooling costs are concentrated in a few hot weeks each year.
Questions
Frequently asked questions
How much does it cost to run a portable air conditioner for 24 hours in Montana?
Running a 1,200W portable air conditioner for 24 hours uses about 28.8 kWh, which costs about $4.32 at Montana’s average rate of 15.0¢/kWh.
How many kWh does a portable air conditioner use per month?
At 8 hours a day, a typical portable air conditioner uses about 292 kWh a month. In Montana that costs $43.78.
Is it expensive to run a portable air conditioner in Montana?
Montana has the 14th-cheapest residential electricity of the 50 states and DC at 15.0¢/kWh — cheaper than most. Running a portable air conditioner here costs about $525 a year at typical use, compared with $642 at the national average rate.
What is the electricity rate in Montana right now?
The average residential electricity rate in Montana was 15.0¢ per kWh in July 2026, according to the latest EIA data — up 5.0% from a year earlier.
Do portable air conditioners use a lot of electricity?
They use about as much as a space heater — typically 800–1,500W — and more than a window AC of the same capacity because they are less efficient.
Portable Air Conditioner costs in nearby states
Other appliances in Montana
Cheapest and priciest states
Comparisons
Sources & method
- Electricity rates: U.S. Energy Information Administration, Electric Power Monthly — average residential retail price, July 2026 (latest available). Retrieved .
- CO₂: EIA State Electricity Profiles, 2024 emissions rate of in-state power generation.
- Default usage for portable air conditioner: 8 hours a day. Typical power 1,200W.
- Formulas, duty cycles and limitations: methodology. Data download: open data (CC BY 4.0).