LG LW1822IVSM
window air conditioner · 18,000 BTU cooling · fits ~900 sq ft
A window AC rated 18,000 BTU — enough cooling for a room of roughly 900 square feet (the 20-BTU-per-square-foot rule).
What actually decides this purchase
We publish 17 units at 18,000 BTU. They run within $18 a year of each other — but they sell for $571 to $843, a 1.5× spread. Efficiency is not what decides this purchase at 18,000 BTU; price, noise and whether it fits your window are. Here is where this unit lands.
At $640 this is at or under the 18,000 BTU median of $640, which is the half of the decision that moves real money — every unit at this size runs within $18 a year of every other, so the efficiency ranking below is a tiebreak, not the argument. Worth comparing against the Keystone KSTAW182WA at $571 and the Friedrich CCV18A30A at 32 dBA for $843.
Price
$640
2nd cheapest of the 3 units we have a price for at this size (median $640). Checked 2026-08-20.
Noise
Not published
The maker publishes no dBA figure we could verify, and noise is not part of the DOE certification. It is the most common complaint about window units, so treat its absence as a real unknown.
Window fit
Measure first
No trustworthy cabinet width on this certificate, so we will not state a fit range.
Circuit
230V needed
Needs a dedicated circuit. Budget an electrician before you buy.
We do not have noise or window fit for this unit and will not estimate them. Everything above that carries a number is from a certification record or the manufacturer's own published sheet.
Buy this unit
$639.99 at Amazon
A window AC is a self-install unit: you set it in the window (or wall sleeve), no contractor or refrigerant charge needed. We verified this listing against the certified record: same brand, the same 18,000 BTU cooling capacity, the same window AC form factor, and in stock at the price shown. Its title doesn’t carry this model number, so treat it as the current equivalent rather than a guaranteed identical SKU.
Sized for ~900 sq ft — measure your room and check your window type before you buy.
Check current price →Affiliate link. We may earn a commission — it never changes your price or our specs. Links to the listing we verified against this unit’s certified brand, capacity and form factor; price can change at Amazon.
The Verified Label — every certified spec
certified 2023-09-18
status: Active
Cooling & efficiency — source: ENERGY STAR / DOE
Fit & install — does it fit your window?
Efficiency & running cost — computed by Verified HVAC Data
Worth keeping in proportion: every unit in the 18,000 BTU class runs within $18 a year of every other. The gap between the cheapest and dearest to buy at this size is 15× larger. Efficiency is the smallest number on this page, which is why it is not at the top of it.
Refrigerant & identity
Brand, warranty & reliability
LG ductless/VRF is a premium-tier Korean line with strong efficiency and a broad service base, but full 10-12 year coverage hinges on registration and installation by an LG Pro/Excellence contractor, and older (2018-and-earlier) inverter boards had elevated failure rates LG has since addressed.
Reliability is our read of published brand assessments (source), not a certified rating — real-world dependability hinges on a correct install more than the brand. Warranty terms are the manufacturer's (policy) and almost always require online registration within 60–90 days for the full length.
Compare similar room ACs
Frequently asked questions
Is 18,000 BTU right for my room, or should I size up?
About 900 square feet is the guide figure, and 17 certified units sit on that shelf. The next shelf up is 24,000 BTU (22 units), about 1,200 sq ft. Below it, 15,000 BTU (7 units) covers about 750 sq ft. Between two shelves, take the smaller one: oversizing is the usual reason a unit cools but leaves the room clammy, which our sizing calculator explains.
Does the LG LW1822IVSM need a special outlet?
Yes. It runs on 230 volts, not the 115-volt outlet a bedroom or living room normally has, so it needs a dedicated circuit installed by an electrician. Budget for that before you buy: most units in its 18,000 BTU class are 115-volt, so a same-size alternative may avoid the wiring entirely.
Will the LG LW1822IVSM fit my window?
The certification record doesn't publish reliable full dimensions for this unit, so measure your opening and compare against the seller's listing before you buy.
Sources. Certification and CEER from ENERGY STAR room-AC data and the DOE compliance certification database. Cooling capacity, dimensions and refrigerant are the manufacturer-certified values. Annual running cost, suggested room size and the percentile are computed by Verified HVAC Data from published ratings and EIA U.S. average electricity prices — see our methodology. Refrigerant GWP is the IPCC value. We publish no star ratings and take no payment for placement. "Not published" means the source registry doesn't disclose it — we never fill a spec with a guess.