The quietest PC cases, by the fans they ship with

Do PC case makers publish noise ratings?

Not for the case itself. NZXT, Thermaltake and Lian Li rate only the fans they ship in it.

Every number here is the maker's rating for one included fan model, at a speed the maker states. NZXT lists it in the included fans section of its tech specs, with model, quantity, speed, airflow, pressure and noise level. Thermaltake prints it in brackets after each fan in its cooling system row, for example "CT140 fan (1500rpm, 30.5 dBA)", and Lian Li gives a block of figures per fan on the product page. None of the three names a measuring distance or a test standard, or says whether the fan was measured in open air or in the case. None of the figures describes a built PC.

A case whose fans are rated at 24.1 dBA is therefore not a 24.1 dBA case. Put a graphics card, a CPU cooler and a power supply inside and you add three more noise sources, none of them counted here, while the panels decide how much of that noise escapes. Mesh lets it out; glass and damped steel hold some of it in. Nobody puts a number on that.

What the figures can tell you is how loud the fans in the box are rated at their stated speed, compared with the fans in another box. Those are the fans you will run unless you replace them.

What is the quietest PC case by its stock fan ratings?

The NZXT H9 Flow, at 22.9 dBA for its three F140Q fans and 24.1 dBA for the rear F120Q, both at 1,350 ± 150 RPM.

Cases are ranked on the figure for the loudest fan they ship with, since that fan sets the floor until you turn it down. Speed sits beside every figure, because it is half the story.

Two Lian Li cases sit outside the table because their figures come with a speed range. Lian Li prints the LANCOOL III's 140 mm fans as "200~1800 RPM ... 33dB-A" and the LANCOOL 207's as "450~1900 RPM ... 34.86 dB-A", without saying which speed in the range the figure belongs to.

NZXT's H7 Flow RGB is left out too. It ships one F360 RGB Core, three fans on a single frame, rated 23.3 dBA at 1,700 ± 200 RPM, and NZXT does not say whether that is one fan or the whole unit.

Fan speed explains most of the spread

NZXT rates its fans at 1,200 to 1,350 RPM, Thermaltake at 1500rpm and Lian Li its LANCOOL 217 at 1550 to 1900 RPM. Look at the speeds and the ranking stops looking like a contest between brands, since the ratings rise in roughly the same order.

The best evidence is inside NZXT's own range. The H6 Flow's F120Q fans are rated 25.1 dBA at 1,200 ± 240 RPM, a slightly higher rating at a lower speed than the 24.1 dBA F120Q in the H5 Flow: same fan model name, different case version, different figure. Small differences between these ratings do not mean much.

A rating at a high speed does not make a fan loud in your build. The LANCOOL 217's two 170 mm front fans move 142.56 CFM at 1550 RPM by Lian Li's figure, far more than NZXT's 60.2 CFM F120Q. Turned down to move the same air, they may well be quieter, though no maker publishes the figure that would settle it.

How do you pick a quiet PC case?

Count the fan mounts rather than the fans. Fans are cheap to add and easy to replace, and a case that takes 140 mm fans at the front and top lets you run large fans slowly. The H9 Flow, Ceres 330 and CTE C700 Air ship with 140 mm fans; the H5 Flow and H7 Flow take them. To fill those mounts yourself, our guide to the quietest 140mm case fans compares fans from Noctua, Scythe, Thermalright and Lian Li at the same stated speed.

Cooler clearance comes next. A tall tower cooler running slowly is quieter than most small coolers running fast; the H7 Flow clears 185 mm, as does the Ceres 330, and the CTE C700 Air clears 190 mm.

Then mind the stock fan speed. NZXT lists 3-pin connectors for its F120Q fans, and a 3-pin fan is slowed by voltage rather than a PWM signal, so check that your motherboard's fan headers support DC mode before you plan a fan curve.

Replace the loudest fans first. If a case ships with fans rated well above the rest of your build, our quietest PC fans guide covers replacements with published ratings. The CPU cooler and the power supply count as much; see the quietest CPU coolers and quietest power supplies.

Four mistakes that make a build loud

The first is reading a fan rating as a case rating. A 22.9 dBA fan does not make a 22.9 dBA PC.

The second is comparing ratings at different speeds: 24.1 dBA at 1,350 RPM and 34.3 dBA at 1550 RPM on a much larger fan are not a like-for-like comparison.

Third comes forgetting what else is inside. The graphics card is often the loudest part of a gaming PC under load, and no case changes that much.

The last is assuming quiet branding means a quiet figure, when the cases sold on silence publish no figure at all.

Do quiet-branded cases like Fractal's Define publish a noise figure?

No. The pages for Fractal Design's Define, Cooler Master's Silencio S600 and Antec's P101 Silent print none.

Fractal Design's Define 7 product page lists three Dynamic X2 GP-14 fans in the box, and its product sheet gives fan mounts and dimensions, but neither prints a noise figure. The noise fields on Fractal's product pages for the Define, North, Meshify, Pop, Era, Focus and Node cases were empty.

Cooler Master's page for the Silencio S600 describes foam, mass-loaded vinyl and two Silencio FP fans without a number, and its US site would not load for us. Antec's P101 Silent page mentions anti-noise panels and prints no figure, and neither do its P10 Flux, P20C and Flux pages. Phanteks' Eclipse P600S and NV5 pages list the fans but no figures, and so do SilverStone's PS15 and Montech's AIR 903 pages.

These cases may well be quiet, but nothing on their makers' pages says so in numbers.