18,000 BTU window air conditioners
The size for a room of about 900 sq ft — every certified unit at this capacity, ranked, with what each one costs to buy and how loud it is.
Data current as of July 12, 2026 · 17 certified units · source AHRI + ENERGY STAR
What actually decides it at this size
We have a price for 3 of these units. They span $571 to $843 to buy, median $640 — while the gap between the cheapest and dearest to run is $18 a year. The price gap is about 15× larger. So at this size the decision is price and noise. Efficiency is the tiebreak, and the table below ranks on it.
CEER is the DOE room-AC efficiency rating. It decides the running cost — which, at a fixed size, is the smallest of the three numbers that matter here.
17 certified units · 16 with a verified place to buy
| Brand & model | CEER | Room size | Quietest | Price | To run | Buy |
|---|---|---|---|---|---|---|
| Midea MAW18S2KWT-A | 16.0 | ~900 sq ft | not published | not tracked | $159/yr | Buy |
| Midea MWCUWH-18CRFN8-MCP0 | 16.0 | ~900 sq ft | not published | not tracked | $159/yr | Buy |
| Frigidaire FHWW185WE2 | 15.0 | ~900 sq ft | not published | not tracked | $169/yr | Buy |
| Hisense AW1823TW3W | 15.0 | ~900 sq ft | not published | not tracked | $169/yr | Buy |
| Keplerx KBRC18RSVE2 | 15.0 | ~900 sq ft | not published | not tracked | $169/yr | Buy |
| Keystone KSTAW182WA | 15.0 | ~900 sq ft | not published | $571 | $169/yr | Buy |
| Midea MAW18R2VWT | 15.0 | ~900 sq ft | not published | not tracked | $169/yr | Buy |
| Midea MAW18RV1CWT | 15.0 | ~900 sq ft | not published | not tracked | $169/yr | Buy |
| Midea MAW18S2VWT-A | 15.0 | ~900 sq ft | not published | not tracked | $169/yr | Buy |
| Midea MWCUWH-18CRFN8-MCN10 | 15.0 | ~900 sq ft | not published | not tracked | $169/yr | Buy |
| LG LW1822IVSM | 14.7 | ~900 sq ft | not published | $640 | $173/yr | Buy |
| Friedrich CCV18A30A | 14.4 | ~900 sq ft | 32 dBA | $843 | $177/yr | Buy |
| HEMA DS-2W1822CI | 14.4 | ~900 sq ft | not published | not tracked | $177/yr | Get quotes |
| TCL H18W4KW | 14.4 | ~900 sq ft | not published | not tracked | $177/yr | Buy |
| TCL H18W4KW-CA | 14.4 | ~900 sq ft | not published | not tracked | $177/yr | Buy |
| TCL T18WQ2S | 14.4 | ~900 sq ft | not published | not tracked | $177/yr | Buy |
| Whirlpool WHAW-181IN | 14.4 | ~900 sq ft | not published | not tracked | $177/yr | Buy |
Capacity and efficiency are AHRI-certified values; $/MMBtu is computed by us from EIA energy prices — see methodology. Heat at 5°F is the number that decides whether a heat pump keeps up in real cold, and most listings omit it.