How loud is the LG 11,800 BTU Through the Wall Air Conditioner?

60 dB(A) indoors, about as loud as a dishwasher.

What size room does the LG 11,800 BTU Through the Wall Air Conditioner cool?

It is rated to cool a room up to 550 sq ft (11,800 BTU · 3.5 kW).

Do I need a professional to install the LG 11,800 BTU Through the Wall Air Conditioner?

Not to replace a unit, but usually yes for a new opening. Sliding it into an existing wall sleeve it fits is a job you can do yourself (it is heavy, so plan on two people), with no refrigerant work. A new installation means cutting an opening through an exterior wall and fitting a sleeve, which is contractor work and usually needs a building permit.

Through-the-wall unit

LG · Model LT12124CNR

11,800 BTU Through the Wall Air Conditioner

A through-the-wall air conditioner rated at 11,800 BTU for rooms up to 550 sq ft. It installs in a wall sleeve.

$549

Live price at Sylvane

Price checked Sep 30, 2026

Price history at Sylvane

Lowest since Jul 25, 2026:$539.99on Jul 25, 2026

Tracked price is up since Jul 25, 2026

Based on 53 prices we have recorded since Jul 25, 2026, not a market average.

Will it cool your room?

Room size (assumed)450 sq ft ≈ 41.8 m²

Fits a 41.8 m² room

This unit's cooling matches a 450 sq ft room. Set your room size to check the fit for your space.

At a glance

Best for replacing a through-the-wall unit in an existing wall sleeve.

Cooling

3.5 kW

Size

Average

Noise

60 dB

Audible

Install: Slides into a wall sleevePermission: A new wall opening usually needs a permit

Performance

Cooling capacity: 11,800 BTU · 3.5 kW
Heating capacity: Cooling only
Room coverage: up to 550 sq ft
Energy Star: Not published
CEER: Not published
Annual energy (cooling): Not published

Noise, size & features

Model number: LT12124CNR
Indoor noise: 60 dB(A)about as loud as a dishwasher
Outdoor noise: Not published
Indoor unit: 24 x 14.44 x 20.13 in
Outdoor unit: None
Refrigerant: R-32
Wi-Fi / app: Not published
Outdoor unit needed: No
Wall sleeve: Fits 26 in. standard sleeves (25½ to 27 in.)
Warranty: 1-Year Limited Warranty

Will it fit your wall sleeve?

LG's manual lists the existing sleeves it fits (25½ to 27 inches wide, from Frigidaire, GE/Hotpoint, Whirlpool, Fedders/Emerson, Carrier and Friedrich), but LG strongly recommends a new LG sleeve and says an existing sleeve's rear louvers must be redirected. LG's own sleeve is the AXSVA1, or the AXSVA4 with a stamped grille (about 25⅞ x 15½ x 16¾ in.). Source: LG owner's manual (hosted by P.C. Richard)

Every through-the-wall AC and PTAC by the sleeve it fits

What is good

At $549 it undercuts 9 of the 12 other 10,000-11,000 BTU through-the-wall units we list with a live price.
Uses R-32 (GWP 675), the low-GWP class new US residential equipment moved to.

What to watch

At 60 dB(A) it is louder than 24 of the 24 other through-the-wall units we list that publish a noise figure.

Installation & the rules that apply

This is a through-the-wall air conditioner. It sits in a sleeve built into an exterior wall, so the window-unit mounting and bracket rules do not apply to it. Swapping it into an existing sleeve is a like-for-like replacement; cutting a new opening changes the building's exterior wall, which usually needs a building permit and, in a condo, co-op or historic building, approval first.

Installation

Slides into a wall sleeve

Refrigerant

R-32

GeneralRenters: get written landlord consent firstReviewed June 2026Often blocks install

GeneralCondo / HOA: exterior changes need approvalReviewed June 2026Permit required

GeneralHistoric / listed buildings: consent before any exterior unitReviewed June 2026Permit required

MassachusettsMassachusetts: local historic district approval (MGL c.40C)Reviewed June 2026Permit required

United StatesUS: local mechanical and electrical permits (vary by city)Reviewed June 2026Permit required

See full rules by region

Common questions about the LG 11,800 BTU Through the Wall Air Conditioner

How loud is the LG 11,800 BTU Through the Wall Air Conditioner?: 60 dB(A) indoors, about as loud as a dishwasher.
What size room does the LG 11,800 BTU Through the Wall Air Conditioner cool?: It is rated to cool a room up to 550 sq ft (11,800 BTU · 3.5 kW).
Do I need a professional to install the LG 11,800 BTU Through the Wall Air Conditioner?: Not to replace a unit, but usually yes for a new opening. Sliding it into an existing wall sleeve it fits is a job you can do yourself (it is heavy, so plan on two people), with no refrigerant work. A new installation means cutting an opening through an exterior wall and fitting a sleeve, which is contractor work and usually needs a building permit.