Who makes the quietest through-the-wall air conditioner?
Frigidaire, with the FHTC103WB1's 50.2 dBA on low, the lowest per-speed figure printed for any current wall unit.
Frigidaire names every speed
Its product specifications sheets carry three rows, Noise Level dBA (Low), (Med) and (High), for each of nine current wall units.
| Frigidaire wall unit | Low | Medium | High |
|---|
| FHTC103WB1, 10,000 BTU | 50.2 | 52.8 | 56 |
| FHTE083WA1, 8,000 BTU with heat | 52 | 54 | 57 |
| FHTC123WB1, 12,000 BTU | 55.3 | 56.8 | 59 |
| FHTC103WB2, 208/230V | 55.7 | 57.9 | 59.5 |
| FHTC123WB2, 208/230V | 57.5 | 59 | 60.2 |
| FHTE103WA2 | 57 | 59 | 60 |
| FHTC142WA2, FHTE123WA2, FHTE143WA2 | 58 | 59 | 61 |
Our Frigidaire air conditioner page sets them beside the brand's window and portable units.
Four wall models from earlier versions of this guide showed as "DISCONTINUED" on frigidaire.com on November 7, 2026: the 8,000 BTU FHTC083WB1, the old top pick at 49.5 dBA on low, the 8,300 BTU FHTC083WA1, the 12,000 BTU FHTC123WA1 and the built-in FFTA083WA1. None is recommended any more.
The 8,000 and 9,800 BTU units get a per-speed row, "dBA Level (High/Mid/Low)", both reading 56/55/53. Every LG wall unit also gets a pair labeled "dBA Level (Indoor / Outdoor)": 56/62 for the LT0816CER, 56/65 for the LT1016CER, 60/66 for the LT1216CER, and 56/63 and 59/65 for the two heat and cool models. Which fan speed the pair describes, LG never says.
Keystone publishes pairs without labels
An "Indoor Noise Level dBA" line runs under each model on Keystone's through-the-wall spec sheet, most with two values: 56.8 / 51.8 for the 8,000 BTU KSTAT08-1D and 60.5 / 56.5 for the 12,000 BTU models. The sheet never ties a value to a speed. The KSTAT08-1D product page does, calling the 51.8 figure "on low".
All three makers' figures appear here in their own wording, and a per-speed figure is never ranked against an unlabeled one. Distances and test standards are missing from all three,
so a decibel or two between brands is noise in the data. Comparisons inside one brand's sleeve lineup are the ones to lean on.
Our decibel chart sets 50.2 dBA next to the hum of a fridge and ordinary talk.
GE Appliances sells a full built-in wall lineup. Its AJCQ08AWJ product page, quick specs sheet, built-in and universal fit wall air conditioners brochure, dimensions and installation guide and owner's manual carry no decibel figure between them. The manual raises noise only to say that air movement sound is normal and to suggest a slower fan setting.
Midea sells in-wall units from 8,000 to 14,000 BTU. Its pages for the MAT08R1ZWT and MAT12R1ZWT give no noise figure, and both were marked "This product is no longer available" when checked, a sign the lineup is being wound down.
Friedrich is the strangest case, since quiet is its whole pitch.
The Uni-Fit and WallMaster lines are built around QuietMaster technology: a solid steel inner wall, high density insulation and counterweights for vibration dampening, with a claim of "up to 25% quieter" footnoted to internal testing against "leading rotary compressor models". The 2026 brochures and the engineering submittals for both lines list cooling capacity, amps, CFM and sleeve dimensions, and not one decibel figure. A claim without a number cannot be ranked, so the category's arguable premium name sits outside this list.
Is a through-the-wall AC quieter than a window unit?
Frigidaire's sheets split the answer. Its inverter window unit beats its wall units, while its two quietest wall units list less than its conventional window unit at every speed.
Every compressor in this guide is a plain rotary unit that cycles on and off. No maker describes a wall model as an inverter, in a year when inverter window units dominate our window air conditioner guide.
That costs the wall units. The Gallery GHWW085TE1, Frigidaire's inverter window unit, reads 40 dBA at its lowest speed and 50 at its highest, which puts its loudest published speed roughly level with the FHTC103WB1's quietest. Against the conventional 8,000 BTU window unit at 53.5, 55.5 and 59 dBA, though, the wall units hold up: the FHTC103WB1 (50.2, 52.8, 56) and the FHTE083WA1 (52, 54, 57) come in lower at low, medium and high, with sleeve mounting putting the compressor in the wall rather than on the sill.
Where the building allows window units and quiet comes first, an inverter window model is the better tool. Where the sleeve is what you have, the FHTC103WB1 holds the best numbers, and at low speed it has nothing to apologize for. If a ductless system is possible, our mini-split guide covers units with indoor and outdoor dB(A) printed for every speed.
Are through-the-wall AC sleeves a standard size?
No. Frigidaire's wall models want a 26 inch wide sleeve, Keystone sells a 25.5 inch one, and Friedrich prints competitor sleeves from 24 1/2 to 27 inches wide.
A wall unit is a chassis that slides into a sleeve, and the sleeve does more for noise than it gets credit for. It carries the unit's weight, and a loose fit leaves gaps that leak sound and air around the chassis. Keystone states its through-the-wall units are designed for wall installation and not for a standard window, and the other makers sell theirs the same way, as chassis for a sleeve.
Every unit here ships without one. Frigidaire's take sleeve part 912001373 and tolerate walls up to 18 inches thick. Keystone sells the KSTSLV1, 25.5 inches wide. LG includes a trim kit and rear grille and sells its sleeve separately.
Measure the sleeve you have before you shop. Friedrich's submittal prints a whole table of competitor sleeve dimensions for a reason: most wall unit purchases are replacements into someone else's old sleeve. A Frigidaire built-in shows the trap. The discontinued FFTA083WA1 blew air out of the top through a swing louver and sat in a sleeve 25 5/16 inches wide, while the current FHTC103WB1, FHTC123WB1 and FHTE083WA1 blow out the front and list a 26 inch sleeve.
Check the outlet before the decibels
The 8,000 BTU class, LG's cool-only units and Frigidaire's FHTC103WB1 and FHTC123WB1 all run on a standard 115V outlet. Not every wall unit does. LG's two heat and cool models need 208/230V, Frigidaire sells 208/230V versions such as the FHTC103WB2, and Keystone says its 12,000 BTU KSTAT12-2D requires a special 230-volt/20-amp outlet and will not operate on a standard one.
Many older buildings put a 230V receptacle behind the sleeve for exactly these units; many did not. It cuts the candidate list in half.
What size wall air conditioner do I need?
Friedrich's cooling sizing guide, one of the genuinely useful things in its literature, puts 300 to 350 sq ft at 8,000 BTU, 400 to 450 at 10,000 and 450 to 550 at 12,000, assuming normal insulation. It adjusts
10 percent either way for shade or strong sun, and adds 500 BTU per person beyond two and 4,000 BTU for a kitchen.
The noise sheets give a second reason not to oversize. Frigidaire's 12,000 BTU FHTC123WB1 sits 5.1 dBA above the 10,000 BTU FHTC103WB1 on low (55.3 against 50.2) and 3 above on high (59 against 56). Keystone's 12,000 BTU models list 60.5 dBA where its 8,000 BTU unit lists 56.8, and LG's 12,000 BTU unit lists 60 indoor against 56 for its smaller ones.
Size explains only part of it. Frigidaire's 8,000 BTU FHTE083WA1, which adds an electric heater, lists 52 on low, 1.8 above the bigger FHTC103WB1, so compare models of the same type before reading anything into capacity alone.
How much does a through-the-wall air conditioner cost?
From $549.99 to $869 at the maker's regular price on November 7, 2026, for the units in this guide. Wall units run $150 to $250 more than window units of the same size.
Keystone is the value play: $549.99 for the KSTAT08-1D and $649.99 for the 230V 12,000 BTU unit, on a site that points buyers to retailers rather than showing stock. LG listed $579 for the 8,000 BTU LT0816CER and $629 for the 9,800 BTU LT1016CER, both in stock that day, and showed no price for the LT1216CER or either heat and cool model, only a retailer finder. Frigidaire lists a regular $799 for the FHTC103WB1 and the FHTE083WA1 and $869 for the FHTC123WB1, but all nine of its current wall units were marked out of stock on its site that day. If you need cooling soon, plan around the LG or the Keystone.
A new sleeve, if you need one, is another cost on top.
Four mistakes wall AC shoppers make
Keystone's 51.8 and Frigidaire's 50.2 look close. Only Frigidaire's sheet names the speed for every figure it prints.
Assuming the premium brand has the numbers
Friedrich charges the most and publishes the least for its wall units, a percentage claim against unnamed rivals and nothing else. Its PTAC service manuals do carry sound tables, which is why our PTAC guide can rank them.
Ignoring the outdoor side
LG alone tells you what leaves the back of the unit, up to 66 dBA. When the wall faces a neighbor's bedroom or a shared courtyard, that outdoor figure counts as much as the indoor one.
Buying capacity you do not need
Frigidaire, LG and Keystone all print higher figures for their 12,000 BTU wall units than for their smaller cool-only units.
New to decibel specs? Start with dBA explained, and read why a Keystone dBA figure and an LG one do not line up before weighing them against each other. How quiet is quiet enough covers what to aim for in a bedroom.
