Buying guides
Straight answers to the AC questions people ask
Every guide gives a direct recommendation, computed from the same live catalog and sizing rules as our comparison tool, so the answer is real, current and never paid for. Pick the question closest to yours.
Prices last refreshed Nov 10, 2026
Not sure what size you need?
Enter your room and get a straight BTU target, climate-adjusted, plus the in-stock units that fit.
How much does an air conditioner cost?
Middle prices and ranges for window, portable, through-the-wall and mini-split units, size by size, from what is in stock today.
How much does a mini-split cost?
What every size costs in stock today, DIY kits against units an installer fits, and what installation adds.
When is the best time to buy an air conditioner?
What the same models at the same stores cost month by month since July, and how many sold out along the way.
Is there a window air conditioner that is a heat pump?
Which window units are real heat pumps, how cold each still heats, and what an hour of that heat costs against a coil.
Is there a through-the-wall air conditioner that is a heat pump?
Which PTAC and slide-in wall units are heat pumps, the sleeve each fits, and when each switches to electric heat.
How many watts does an air conditioner use?
Watts, amps and the cost of an hour for every size of window, portable, through-the-wall and mini-split unit, from each model's own figure.
How cold can a mini split heat?
What each mini split still delivers at 5°F and 17°F as ENERGY STAR certified it, which are rated for cold climates, and live prices.
How much does it cost to heat with a mini split?
A million BTU of heat from a mini split against gas, propane, oil and a space heater this winter, by region, with a converter for your own bill.
What size portable air conditioner do I need?
The room chart in SACC, the Department of Energy rating a portable is sized by, with every portable's box rating beside it.
By room size
How many BTU your room needs, and the real units sized to match.
What is the best air conditioner for a 150 sq ft room?
Top pickLG 5,000 BTU Window Air Conditioner In stockWhat is the best air conditioner for a 250 sq ft room?
Top pickAmana 6,000 BTU Window Air Conditioner with Electronic Controls - AMAP061BW In stockWhat is the best air conditioner for a 350 sq ft room?
Top pickLG 8,000 BTU Wi-Fi Enabled Window Air Conditioner LW8024RSM In stockWhat is the best air conditioner for a 500 sq ft room?
Top pickPioneer Diamante Essenza 11,500 BTU Ductless Mini Split 230V In stockWhat is the best air conditioner for a 700 sq ft room?
Top pickGE Smart Window Air Conditioner 14,000 BTU 115V In stockBy cooling power (BTU)
The best unit at each standard BTU size, from real in-stock picks.
What is the best 5,000 BTU air conditioner?
Top pickLG 5,000 BTU Window Air Conditioner In stockWhat is the best 6,000 BTU air conditioner?
Top pickAmana 6,000 BTU Window Air Conditioner with Electronic Controls - AMAP061BW In stockWhat is the best 8,000 BTU air conditioner?
Top pickWindmill 8,000 BTU Inverter Smart Window Air Conditioner In stockWhat is the best 9,000 BTU air conditioner?
Top pickSenville Leto 9,000 BTU Mini Split Heat Pump 115V In stockWhat is the best 10,000 BTU air conditioner?
Top pickFrigidaire 10,000 BTU Wi-Fi Enabled Window Air Conditioner In stockWhat is the best 12,000 BTU air conditioner?
Top pickFrigidaire 12,000 BTU Wi-Fi Enabled Window Air Conditioner In stockWhat is the best 14,000 BTU air conditioner?
Top pickGE Smart Window Air Conditioner 14,000 BTU 115V In stockWhat is the best 15,000 BTU air conditioner?
Top pickAmana 15,000 BTU Window Air Conditioner with Electronic Controls In stockWhat is the best 18,000 BTU air conditioner?
Top pickFrigidaire Air Conditioner Window Inverter with Wi-Fi 18,000 BTU 230 V in White In stockWhat is the best 24,000 BTU air conditioner?
Top pickLG 23,000 BTU Window Air Conditioner with Heat In stockBy system type
The best of each kind: portable, window, through-the-wall and mini-split.
What is the best portable air conditioner?
Top pickLG 10,000 BTU Portable Air Conditioner In stockWhat is the best window air conditioner?
Top pickWindmill 8,000 BTU Inverter Smart Window Air Conditioner In stockWhat is the best mini-split air conditioner?
Top pickPioneer Diamante Essenza 11,500 BTU Ductless Mini Split 230V In stockWhat is the best through-the-wall air conditioner?
Top pickLG 9,800 BTU Through-the-Wall Air Conditioner In stockBy price
The cheapest to buy and the cheapest to run, from real in-stock prices.
What is the cheapest air conditioner you can buy right now?
Top pickLG 5,000 BTU Window Air Conditioner In stockWhat is the best cheap window air conditioner?
Top pickLG 5,000 BTU Window Air Conditioner In stockWhat is the best budget portable air conditioner?
Top pickFrigidaire 8,000 BTU Portable Air Conditioner In stockWhat is the cheapest air conditioner to run?
Top pickGE Profile Inverter Smart Window Air Conditioner 8,000 BTU in White In stockBy what matters to you
Quietest, most efficient, heats too, and best for renters.
What is the quietest air conditioner for a bedroom?
Top pickSoleus Air 10,000 BTU Saddle Window Air Conditioner w/Heat In stockWhat is the most energy-efficient air conditioner?
Top pickGE Profile Inverter Smart Window Air Conditioner 8,000 BTU in White In stockWhat is the best air conditioner for renters?
Top pickWindmill 8,000 BTU Inverter Smart Window Air Conditioner In stockWhat is the best air conditioner that also heats?
Top pickPioneer Diamante Essenza 11,500 BTU Ductless Mini Split 230V In stockWhat is the best mini-split for a cold climate?
Top pickSenville Aura 9,000 BTU Mini Split Heat Pump In stockWhat is the best window air conditioner with heat?
Top pickSoleus Air 10,000 BTU Saddle Window Air Conditioner w/Heat In stockWhat is the best through-the-wall air conditioner with heat?
Top pickFriedrich Kuhl 10,000 BTU Window & Wall Air Conditioner Heat Pump In stockIn-depth articles
Inverter vs Non-Inverter Air Conditioner (2026)
Every ENERGY STAR window AC is now an inverter, and 2026 federal rules retire most of the rest. What the inverter premium costs, saves, and when to skip it.
What It Costs to Run an Air Conditioner in 2026
The sticker is the smallest part of what an AC costs you. Using live prices and ENERGY STAR data on 459 units, here is what a year of cooling really costs.
What Size Air Conditioner Do I Need? BTU Guide 2026
How many BTU do you need to cool your room? The real BTU-per-square-foot math, the adjustments that matter, and why a bigger AC is usually worse.
Most 'Air Conditioners' Online Are Not Air Conditioners. Here Is How to Tell
Search a marketplace for 'air conditioner' and the first page is full of fans, evaporative coolers, and 'mini AC' gadgets that cannot cool a closed room. Here is how to spot a real one, decode the specs, and avoid the rules that catch buyers out.