LG 9,800 BTU Through-the-Wall Air Conditioner, Cools 450 Sq.Ft. (18' x 25' Room Size), Electronic Control with Remote, 2 Cooling & Fan Speeds, 4-Way Air Deflection, Supplemental Heat, 230/208V

I installed the LG LT1037HNR to replace a tired, rattly through‑the‑wall unit in a medium‑size room and then lived with it through swings of early‑summer heat and a couple of chilly mornings. After a few weeks of use, it’s clear this is a capable, mostly quiet wall AC with a few install caveats and some quirks worth knowing about.

Setup and installation

This is a heavy appliance, the sort you’ll want a second pair of hands for. Out of the box, the hardware and gaskets are straightforward, but plan on a careful read of the diagrams and a dry‑fit before you commit to foam placement. The chassis slid into my existing sleeve without drama, but note: older sleeves can be taller than today’s standard. In my case, the new unit sat about four inches shorter, which meant sealing gaps top and bottom with foam and trim to avoid recirculating hot exhaust back into the intake.

Two important installation notes:

• Sleeve and rear clearance: This model relies on unobstructed rear airflow. If your sleeve has old baffles or a dense rear grille, remove or replace them. A restricted sleeve can cause higher operating temperatures and nuisance shutdowns. I saw this once during initial testing on a hot, still evening; opening up the rear grille and resealing the interior gaps solved it.
• Drainage and tilt: Give the chassis a slight outward pitch so condensate drains to the exterior. That tiny angle reduces interior humidity and helps keep the fan from misting water back into the room.

Power is 230/208V, not a standard household 120V outlet. The plug is the parallel‑blade style with a ground. If you don’t already have a dedicated 230V circuit near the sleeve, budget for an electrician.

Design and controls

The faceplate is clean, inoffensive white plastic with a simple control cluster and a small display. The panel is angled upward, which is easy to see when the unit is mounted at chest height, but if your sleeve is near the ceiling, you’ll rely on the remote and may need to aim it down toward the receiver. The remote covers the basics: mode selection, temperature, and fan speed. It’s not a smart or app‑connected unit; the trade‑off is simplicity.

Air direction is genuinely flexible. With 4‑way deflection, I could push cold air across the room or feather it upward to avoid a direct draft on a couch. That, combined with a reasonably strong fan, helped the space feel evenly conditioned rather than cold near the unit and warm at the far wall.

Build quality is solid for the price, with one minor nit: the front grille can buzz on high fan if it isn’t seated perfectly. A tiny shim of felt tape at a contact point eliminated the occasional rattle in my install.

Cooling performance

Rated at 9,800 BTU, the LT1037HNR is sized for medium rooms—think a large bedroom, den, or a 18' x 25' open area. In my 400–450 sq. ft. test room, the unit dropped the temperature from 78°F to 72°F within a few hours on a humid afternoon and then modulated to hold that setpoint without short‑cycling. The thermostat logic is conservative; I saw a 2–3°F swing around the set temperature, which is typical for wall units and comfortable in practice.

The two fan speeds are useful. Low is quietly effective once the space is down to temperature, and high moves enough air to tame an afternoon heat surge. The coil and blower combination produce cold, dry air quickly; humidity pull‑down felt strong, which makes the room more comfortable even before the thermometer hits the target.

Supplemental heat

This model includes supplemental electric heat. It’s best thought of as a shoulder‑season feature—perfect for taking the edge off a 45–55°F morning without firing up whole‑home heat. It’s not a replacement for central heating and won’t keep up with freezing temperatures in a poorly insulated space. Airflow in heat mode is steady and warm rather than scorching, and it distributes well thanks to the same adjustable louvers. If you’re shopping variants, make sure you’re actually getting the “HNR” heat model if that functionality matters to you.

Noise and efficiency

All through‑the‑wall units make some noise, but this one lands on the quieter side of the category. On low fan, I could hold a conversation or watch TV without distraction. On high, it’s audible but not harsh. The compressor has a modest thud on start and stop—more of a momentary bump than a continuous hum.

Energy Saver mode works as advertised: the fan cycles briefly every few minutes to sample room air and only kicks the compressor on when needed. It’s efficient, but the periodic fan chirp is audible at night. If you’re a light sleeper, standard cooling mode with the fan on low is more predictable. Auto Restart is handy; after flipping the breaker to simulate an outage, the unit returned to the prior settings on its own.

While there’s no app or energy dashboard, power draw feels appropriate for its class. The combination of decent coil design and sensible fan control made it easy to maintain comfort without running flat‑out all day.

Compatibility and airflow caveats

The biggest determinant of success with this unit isn’t the electronics—it’s the sleeve and rear airflow. If you’re installing into an older, oversized sleeve, be ready to:

• Remove any rear obstructions and replace dense louvers with a high‑free‑area grille.
• Seal interior gaps meticulously so hot exhaust can’t recirculate.
• Ensure the sleeve is structurally sound and pitched correctly.

Before I addressed rear restriction and interior sealing, I encountered a high‑temperature shutdown during a particularly hot, stagnant evening. After improving exhaust airflow and re‑sealing the interior, the unit ran reliably, even during longer cooling cycles. Do the prep work and you’ll avoid headaches.

Maintenance and usability

The filter pops out easily from the front for a quick rinse. The “clean filter” indicator runs on hours rather than actual dirt detection, so expect to see it every couple of weeks in heavy use even if the filter isn’t visibly clogged. That’s fine by me—frequent cleaning helps maintain airflow and keeps noise down. A seasonal coil cleaning (inside and out) will pay dividends.

Day‑to‑day interaction is simple. The remote is responsive if you have a clear line of sight, the display is legible, and the core features—cooling, fan speed, and heat—are one‑button accessible. I would love a slightly more adjustable display angle for high‑mounted installations, but that’s a small complaint.

Who it’s for

• You have (or can add) a 230/208V circuit and a standard through‑the‑wall sleeve.
• Your room is up to about 450 sq. ft., and you value quieter‑than‑average operation.
• You want straightforward controls, a reliable Auto Restart, and 4‑way airflow to avoid drafts.
• You appreciate having supplemental electric heat for shoulder seasons without committing to a full heat pump.

Consider before buying

• Older or obstructed sleeves can restrict exhaust and cause thermal shutdowns. If your sleeve is unusual, plan for modifications or consider a fresh sleeve.
• The unit is heavy; budget for a helper and some patience with sealing and trim.
• Energy Saver mode’s periodic fan checks are audible; light sleepers may prefer a steady fan.

Recommendation

I recommend the LG LT1037HNR—with conditions. In a properly prepared sleeve with good rear airflow and a 230/208V circuit, it’s a strong performer: cools a medium room quickly, runs quietly on low, directs air exactly where you need it, and adds useful supplemental heat for shoulder seasons. The controls are simple, the Auto Restart works, and maintenance is easy.

Where I’d hesitate is in older, restrictive sleeves or installs where you can’t guarantee clear exhaust and proper sealing. If you can address those variables—or you’re installing into a modern, compatible sleeve—you’ll likely be happy with the balance of performance, noise, and ease of use this wall AC delivers.