Brand

Keystone air conditioners: every model we track, compared

We track 26 Keystone air conditioner models: 17 window units, 6 through-the-wall units and 3 portables, 5,000 BTU to 25,000 BTU. 20 are in stock at a retailer right now, from $279.99. 1 CPSC air conditioner notice we hold names Keystone: Midea U and U+ Window Air Conditioners (2025, filed by Midea). None of the 22 Keystone models we track that state a model number is named in a notice we hold, which is not a safety certification. 4 listings state no model number, so check the label on the unit itself.

Models
26
Sizes
5,000 to 25,000 BTU
In stock now
20
Notices naming it
1

How Keystone compares with other brands, size by size

At each standard size where Keystone and another brand both have a model in stock, we check whether Keystone's cheapest model is the cheapest, its best efficiency rating the highest and its quietest verified noise rating the lowest. A price counts as cheaper only by at least $20 and 5%, and only between models installed the same way (a do-it-yourself kit is not priced against an installer-fitted system); anything closer is level. We do not rate reliability: no public data reports repair rates by brand.

Window units

  • Keystone has 12 window units in stock at 6 standard sizes; at all 6, another brand has one in stock too.
  • Of the 6 sizes compared like for like, its cheapest model is the cheapest in stock by at least $20 and 5% at 1; it is within $20 or 5% of the cheapest other brand at 1; another brand is cheaper by at least $20 and 5% at 4.
  • Of the 4 sizes where both publish a CEER rating, it is within 0.5 CEER of the best at 2; another brand rates higher by at least 0.5 CEER at 2.
  • Of the 4 sizes where both have a verified noise rating, it is within 3 dB of the quietest at 2; another brand is quieter by at least 3 dB at 2.
  • 4 of its 12 in-stock models are ENERGY STAR certified.
  • Where its listings state one, the compressor warranty is 1 to 4 years.
Keystone against the cheapest other brand at each size
SizeKeystone fromOthers from
8,000 BTU$279.99$269 GE
10,000 BTU$329.99$309 GE
12,000 BTU$449.99$379 GE
14,000 BTU$549.99$409 GE
18,000 BTU$679.99$548 Frigidaire
24,000 BTU$919.99 (25,000 BTU)$999 Perfect Aire (25,000 BTU)

Through-the-wall units

  • Keystone has 5 through-the-wall units in stock at 4 standard sizes; at all 4, another brand has one in stock too.
  • Of the 4 sizes compared like for like, it is within $20 or 5% of the cheapest other brand at 1; another brand is cheaper by at least $20 and 5% at 3.
  • Of the 4 sizes where both have a verified noise rating, it is within 3 dB of the quietest at 3; another brand is quieter by at least 3 dB at 1.
  • None of its 5 in-stock models is ENERGY STAR certified.
  • Where its listings state one, the compressor warranty is 1 to 5 years.
Keystone against the cheapest other brand at each size
SizeKeystone fromOthers from
8,000 BTU$569.99$529 Frigidaire
10,000 BTU$569.99$489 LG (9,800 BTU)
12,000 BTU$649.99$549 LG (11,800 BTU)
14,000 BTU$619.99$649.99 TCL

Keystone window air conditioners (17)

Smallest first. "Not published" means the listing does not state that figure.

Keystone through-the-wall air conditioners (6)

Smallest first. "Not published" means the listing does not state that figure.

Keystone portable air conditioners (3)

Smallest first. "Not published" means the listing does not state that figure.

Prices are live retailer offers and change often; compare.ac may earn a commission on purchases, at no cost to you. Where one model number is sold as more than one listing, the row shows the cheapest and links the others. Portable units are often advertised by their older ASHRAE rating; the DOE's SACC rating is lower, so a portable's BTU does not compare directly with a window unit's.

CPSC air conditioner notices that name Keystone

Every notice we hold that names the brand, newest first, whoever filed it, including notices for models no retailer we track sells. A notice covers the model numbers it lists, not every Keystone unit.

Who is behind Keystone

Keystone's website is owned and run by Four Seasons Trading Company, LLC. CPSC recall 25-320 says the U-shaped window units sold under the Keystone name were made by Midea, and a Keystone window air conditioner owner's manual says the units it covers are warranted by Midea and serviced by Midea Consumer Services or a Midea-authorized servicer.

Sources: Keystone privacy policy ; CPSC recall 25-320 (June 5, 2025) ; Keystone window air conditioner owner's manual (hosted by Sylvane) , read October 21, 2026.

Work out which size your room needs

Keystone questions, answered

Is Keystone a good air conditioner brand?

We do not score brands, and no public data reports repair rates by brand. Here is how its in-stock models compare with every other brand's at the same size. For its window units: of the 6 sizes compared like for like, its cheapest model is the cheapest in stock by at least $20 and 5% at 1; it is within $20 or 5% of the cheapest other brand at 1; another brand is cheaper by at least $20 and 5% at 4. Of the 4 sizes where both publish a CEER rating, it is within 0.5 CEER of the best at 2; another brand rates higher by at least 0.5 CEER at 2. Of the 4 sizes where both have a verified noise rating, it is within 3 dB of the quietest at 2; another brand is quieter by at least 3 dB at 2. 4 of its 12 in-stock models are ENERGY STAR certified. For its through-the-wall units: of the 4 sizes compared like for like, it is within $20 or 5% of the cheapest other brand at 1; another brand is cheaper by at least $20 and 5% at 3. Of the 4 sizes where both have a verified noise rating, it is within 3 dB of the quietest at 3; another brand is quieter by at least 3 dB at 1. None of its 5 in-stock models is ENERGY STAR certified. 1 CPSC air conditioner notice we hold names Keystone: Midea U and U+ Window Air Conditioners (2025, filed by Midea). None of the 22 Keystone models we track that state a model number is named in a notice we hold, which is not a safety certification. 4 listings state no model number, so check the label on the unit itself.

Who makes Keystone air conditioners?

Keystone's website is owned and run by Four Seasons Trading Company, LLC. CPSC recall 25-320 says the U-shaped window units sold under the Keystone name were made by Midea, and a Keystone window air conditioner owner's manual says the units it covers are warranted by Midea and serviced by Midea Consumer Services or a Midea-authorized servicer.

Has Keystone had air conditioner recalls?

1 CPSC air conditioner notice we hold names Keystone: Midea U and U+ Window Air Conditioners (2025, filed by Midea). None of the 22 Keystone models we track that state a model number is named in a notice we hold, which is not a safety certification. 4 listings state no model number, so check the label on the unit itself. A notice covers specific model numbers, so check the number on a unit's own label against it before buying or using one.

What sizes do Keystone air conditioners come in?

Window units: 5,000, 8,000, 10,000, 12,000, 14,000, 18,000, 24,000 and 25,000 BTU. Through-the-wall units: 8,000, 10,000, 12,000 and 14,000 BTU. Portables: 12,000 and 14,000 BTU. Match the size to your room with the sizing calculator rather than picking the biggest one.

How much do Keystone air conditioners cost?

Window units in stock: $279.99 to $919.99. Through-the-wall units in stock: $569.99 to $679.99. Portables in stock: $579.99 to $649.99. Prices are live retailer offers and change often.

Keystone against other brands, and its product lines

Keystone vs LG window air conditionersKeystone vs Whirlpool window air conditionersKeystone vs Frigidaire window air conditioners

More air conditioner brands

MRCOOL air conditionersSenville air conditionersPioneer air conditionersLG air conditionersFrigidaire air conditionersFriedrich air conditionersGE air conditionersMidea air conditionersHisense air conditionersWhirlpool air conditionersTCL air conditionersAmana air conditionersPerfect Aire air conditionersWhynter air conditionersEvery brand, side by side