LG LW1823HR 18,000 BTU Window AC with Heat Review: 230V Combo
An 18,000 BTU 230/208V window air conditioner with supplemental heat for rooms up to 1,000 sq. ft. Includes a remote, 24-hour timer, 4-way air deflection and Auto Restart. Needs a NEMA 6-20 outlet.
By Daniel Brooks
Updated October 8, 2026
The LG LW1823HR 18,000 BTU Window Air Conditioner with Heat is a 230/208V cooling and heating combo for large rooms up to 1,000 square feet. LG adds a supplemental heat option for cooler days, so one window unit can cover most of the year. Among large conventional window air conditioners, it is aimed at basements, living rooms and apartments.
It needs a special 230/208V LCDI plug (NEMA 6-20), a large window and serious lifting help. We evaluated it based on the manufacturer’s specifications.
Our Verdict
This LG is a practical heat and cool combo for large spaces. Its strongest points are 18,000 BTU of cooling, supplemental heat, a digital control panel and remote, 2 cooling, heating and fan speeds, a 24-hour on/off timer, 4-way air deflection, Auto Restart and a filter light reminder.
The trade-offs are significant. It weighs 126 pounds, requires a NEMA 6-20 230/208V outlet, has only 2 fan speeds, and the specification sheet lists 61 dB. The listing does not state the heating capacity. It holds 3.8 stars from 90 ratings. If you have the electrical supply and want one unit for summer cooling and mild-weather heat in a large room, it is worth considering.
LG 18,000 BTU Window Air Conditioner with Heat
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Key Specifications
| Feature | Specification |
|---|---|
| Brand | LG |
| Model | LW1823HR |
| Type | Window air conditioner with supplemental heat |
| Cooling Capacity | 18,000 BTU |
| Heating | Supplemental heat (capacity not listed) |
| Room Size (listed) | Up to 1,000 sq. ft. (25′ x 40′) |
| Noise Level | 61 dB |
| Voltage / Power | 230/208V, 2427W, LCDI plug (NEMA 6-20) |
| Window Fit | 29″ to 41″ wide, 18″ minimum height |
| Dimensions | 30.5″D x 25.5″W x 16.8″H |
| Weight | 126 pounds |
| Fan Speeds | 2 cooling, heating and fan speeds |
| Airflow | 4-way air deflection |
| Controls | Digital control panel, remote, 24-hour on/off timer, Auto Restart |
| Filter | Removable, washable mesh filter with filter light reminder |
| Compressor | Rotary scroll, no inverter |
| Refrigerant | R-32 |
| Warranty | 1 year limited |
Cooling Capacity and Room Size
LG rates the LW1823HR at 18,000 BTU for rooms up to 1,000 square feet, about 25′ x 40′. It suggests bedrooms, offices, basements, apartments and even multiple small rooms on the same floor, though airflow into side rooms depends heavily on your layout.
For most homes, this unit makes the most sense in a large open living area, a finished basement or a big family room. In a smaller room, it would be oversized and cycle off before removing much humidity.
The 4-way air deflection helps push air toward the far end of a long room, which matters more at this size than in a compact bedroom.
ENERGY STAR publishes this general guide for sizing a room air conditioner by floor area:
| Room Size (sq ft) | Cooling Capacity (BTU/hr) |
|---|---|
| 100 to 150 | 5,000 |
| 150 to 250 | 6,000 |
| 250 to 300 | 7,000 |
| 300 to 350 | 8,000 |
| 350 to 400 | 9,000 |
| 400 to 450 | 10,000 |
| 450 to 550 | 12,000 |
| 550 to 700 | 14,000 |
| 700 to 1,000 | 18,000 |
Adjust for your room: reduce capacity by 10 percent for a heavily shaded room, increase it by 10 percent for a very sunny room, add 600 BTU for each regular occupant beyond two, and add 4,000 BTU if the unit cools a kitchen. Source: ENERGY STAR.
At its listed 18,000 BTU, it lines up with rooms of about 700 to 1,000 square feet, which matches LG’s coverage claim.
Installation and Fit
The listed window opening is 29 to 41 inches wide with a minimum height of 18 inches. The cabinet is 30.5 inches deep, 25.5 inches wide and 16.8 inches tall, and weighs 126 pounds. An installation kit is included.
This is a job for at least two strong people, and a professional installer is worth considering. Follow the manual for support brackets so the unit is fully supported from below. LG specifies a 230/208V LCDI plug that requires a NEMA 6-20 receptacle. Never use an adapter or extension cord, and have an electrician install or confirm the circuit.
Noise, Energy Use and Efficiency
The specification sheet lists 61 dB. That is typical for an 18,000 BTU fixed-speed unit and acceptable in a large living area with background noise, but it is not a quiet bedroom unit.
The power draw is 2427 watts. The listing does not give a reliable efficiency rating, so check the EnergyGuide label for the official CEER. The compressor has no inverter. The 24-hour timer is the main tool for limiting running time.
Controls and Smart Features
The digital control panel and included remote handle all settings. You get 2 cooling, heating and fan speeds, a 24-hour on/off timer and 4-way air deflection, which directs air where it is needed across a large room.
Auto Restart turns the unit back on after a power failure, in either heating or cooling. There is no Wi-Fi or app control.
Supplemental heat is designed for cooler days rather than cold winters. Use it to take the chill off in spring and fall, and keep a primary heat source for winter.
Maintenance and Drainage
The removable, washable mesh filter is easy to clean, and a filter light reminder tells you when it is due. In a unit used for both heating and cooling, it may run for more months of the year, so check the filter regularly.
The listing does not describe condensate drainage. Check the manual for how water is handled in both modes. Removing a 126 pound unit each season is a major job, so follow the manual’s guidance on seasonal care.
Pros and Cons
| Pros | Cons |
|---|---|
| 18,000 BTU cooling plus supplemental heat | Requires a NEMA 6-20 230/208V outlet |
| Remote and 24-hour on/off timer | Very heavy at 126 pounds |
| 4-way air deflection | Only 2 fan speeds |
| Auto Restart after power failures | Heating capacity not listed |
| Filter light reminder | Specification lists 61 dB |
Who Should Buy It
| Who Should Buy It? | Who Should Look Elsewhere? |
|---|---|
| Large rooms of 700 to 1,000 sq. ft. | Homes with only standard outlets |
| Basements and open living areas | Anyone needing a primary winter heater |
| Buyers who want one unit for cooling and mild heat | Light sleepers in a bedroom |
| Homes with a 230V circuit near the window | Anyone without help for a 126 pound install |
| Buyers who prefer simple remote control | Smart home users wanting app control |
Final Verdict
The LG LW1823HR 18,000 BTU Window Air Conditioner with Heat gives large rooms strong cooling plus supplemental heat for cooler days, with a remote, 24-hour timer, 4-way air deflection and Auto Restart. It suits a basement or open living area up to 1,000 square feet with a NEMA 6-20 circuit. The compromises are a 126 pound weight, only 2 fan speeds and no stated heating capacity. You can check the current price and details for the LG LW1823HR 18,000 BTU Window Air Conditioner with Heat, or compare other 18,000 BTU window air conditioners.
Frequently Asked Questions
What outlet does the LG LW1823HR need?
LG specifies a 230/208V LCDI plug that requires a NEMA 6-20 receptacle. It will not work on a standard household outlet.
Can it heat a room in winter?
It offers supplemental heat for cooler days. LG does not list the heating capacity, so treat it as a supplement rather than a primary heat source.
What size room does it cool?
LG rates it for rooms up to 1,000 square feet, about 25′ x 40′.
How heavy is it?
It weighs 126 pounds. Plan on at least two strong people or a professional installer.
About the author
Daniel Brooks is a home cooling editor at WikiCooling, covering window, portable, through-the-wall and mini-split air conditioners, fans, and dehumidifiers. He researches cooling capacity, energy efficiency, noise levels, installation requirements, and buyer feedback to help homeowners choose the right unit for their room size, climate, and budget.