Lennox's figures come from its Expanded Sound Data handbook, Form 211229, dated June 2026, which covers the brand's R-454B products in production. For each unit size it prints octave band levels, a Sound Rating Number, and estimated sound pressure at five distances.
The handbook's footnote defines the headline number: "Tested according to AHRI Standard 270-2008 test conditions. Sound rating Number is the overall A-Weighted Sound Power Level, (LWA), dB (100 Hz to 10,000 Hz)."
Product pages carry a shorter "Sound Rating" row, usually prefixed "As low as". The handbook outranks that row everywhere they differ, and the differences get their own section further down this page.
Unit codes in the tables read in thousands of BTU per hour: an 018 is a 1.5 ton unit, an 024 a 2 ton, an 036 a 3 ton, up to the 060 at 5 tons. Codes such as 041 and 047 are additional 3.5 and 4 ton builds.
How quiet are Lennox's variable capacity air conditioners?
Lennox's three variable capacity condensers carry a minimum and a maximum per size, with minimums from 58 to 72 dBA. The spread matters more than any single number, since the compressor spends most of a mild day near the bottom of it.
- SL25KCV, Signature, $$$$ tier: 58 dBA minimum at 2, 3, 4 and 5 tons; maximums of 68, 70, 73 and 74 dBA in the same order.
- EL22KCV, Elite, $$$ tier: minimums step up with size, 60, 61, 62 and 63 dBA from 2 through 5 tons; maximums of 68, 73, 74 and 75 dBA.
- EL18KCV, Elite, $$$ tier: 67 to 70 dBA at 2 tons, 66 to 76 at 3 tons, 72 to 76 at 4, and 67 to 79 at 5.
Only the SL25KCV holds one minimum across the board. The EL18KCV is the eccentric: its 3 ton is the quietest thing in its table and its 4 ton the loudest minimum of any Lennox variable model.
A buyer choosing between the two Elite models at the same tier should decide by tonnage. At 2 or 3 tons they are close; at 4 or 5, the EL22KCV's table is the calmer one by a wide margin.
How many decibels are Lennox's single stage models?
Lennox's single stage condensers list one figure per size, from 71 to 80 dBA, and that figure is the unit's voice whenever the compressor runs. Four current models have tables; the fifth, the R-410A ML14XC1, does not.
- EL16KC1, Elite, $$ tier: 72 dBA on the 018, 030, 041 and 042 units; 73 on the 024, 036 and 047; 75 on the 048; 74 on the 060.
- EL15KC1, Elite, $$ tier, Northern region: 71 dBA on the 030, 72 on the 018, 024 and 042, 73 on the 060, 74 on the 036, and 77 on the 048.
- ML14KC1, Merit, $ tier: 73 dBA on the 018, 75 on the 024 and 041, 76 on the 030, 036, 042 and 047, 78 on the 048 and 059, 80 on the 060.
- ML13KC1, Merit, $ tier, Northern region: 73 dBA on the 018, 76 on the 024, 030, 036 and 042, 78 on the 048, 80 on the 060. Three phase builds, sold from 3 tons up, repeat these figures.
- ML14XC1, Merit, $ tier, Northern region: no table found; the page offers only "As low as 73 dB", and the handbook excludes R-410A products.
The quiet pattern inside this group is plain: the Elite pair stays at 77 dBA or below in each size, while both Merit K models cross into the high 70s from 4 tons up and finish at 80.
That 80 dBA on a 5 ton Merit against 74 on a 5 ton EL16KC1 is a 6 dBA gap between two machines doing the same job at one speed each, roughly the difference your ear reads as half again louder.
Where does the two stage ML17KC2 sit?
The ML17KC2 sits between the groups, with single figures of 73 to 75 dBA that describe only one of its two stages. The table gives 75 dBA at 2 tons, 73 at 3, 74 at 4 and 75 at 5, and the three phase builds, offered from 3 tons up, carry the matching numbers.
Lennox writes "Sound levels as low as 73 dBA" in its handbook and "As low as 73 dB" on the page, both resting on the 3 ton.
Missing is any number for low stage. A two stage compressor should spend much of its season on the smaller stage, and that running sound is probably softer, but Lennox leaves it unmeasured in public. Treat the 73 to 75 as what you can count on.
Do Lennox's "as quiet as" claims match its sound tables?
No, except on the SL25KCV and the EL22KCV, whose "as quiet as" figures match their 2 ton table minimums. On three other current models, the page line and the handbook part ways.
The EL15KC1 is advertised at "As low as 72 dB", yet its 030 unit lists 71 dBA, so Lennox undersells its own best size by a decibel. The EL18KCV's "as quiet as 67 dB" skips past its 3 ton minimum of 66 and hides a 4 ton that never lists below 72.
On the Merit singles, "As low as 73 dB" is the 1.5 ton speaking for the family while the 5 ton ML14KC1 and ML13KC1 sit at 80 dBA, a 7 dBA stretch between claim and biggest build.
None of this is unusual for the industry, and the window heat pump and heat pump markets play the same game with floors. A floor claim tells you a range exists; the table tells you where your size lands in it.
Is the sound rating what you hear from the patio?
No. A Sound Rating Number is sound power, the total acoustic output of the box, while your ear registers sound pressure at a distance. The same handbook translates one to the other for you.
Lennox's estimate columns follow "AHRI Standard 275-2010 method for equipment located on the ground, roof, or on side of building wall with no adjacent reflective surface within 9.8 feet". By that method, the SL25KCV's 58 dBA rating becomes an estimated 51 dBA at 3 feet and 40 at 10 feet, and the 80 dBA Merit figure becomes 73 and 62.
A second wall, a fence line or dense shrubs within that 9.8 feet pushes the level back up, which the footnote itself warns about. For how power and pressure ratings differ across product types, the decibel ratings explainer walks through it.
Which Lennox models sell only in the North?
Three of the nine: the EL15KC1, ML13KC1 and ML14XC1. Each page repeats the same restriction, in the EL15KC1's case "The EL15KC1 is available in the Northern region of North America only."
Lennox points shoppers in the listed Southern states toward the sibling models instead, writing on the listing, "ask your Lennox Dealer about the EL16KC1, which also meets the Lennox standard of excellence", with the matching note for the ML14KC1.
Noise-wise, the geography is kind to the South. The nationwide EL16KC1 caps at 75 dBA where the Northern EL15KC1 reaches 77, and the ML14KC1 and ML13KC1 are near twins, so no region is stuck with a louder table than its neighbor.
