QRS3.0HPD-1: a Baldor-motored 3 HP screw compressor, dryer included, at 61 dBA

Two things on this listing are worth more than the horsepower figure. The first is that the motor is named: a TEFC Baldor, not an unattributed motor of unknown origin. On a machine you expect to run continuously for years, knowing whose motor is turning the airend — and being able to source a replacement or a bearing set from a brand with a real service network — is a practical advantage rather than a badge. The second is that it is quiet. At 61 dBA inside a low sound enclosure this is the quietest machine in Chicago Pneumatic's screw range that we list, which decides whether the compressor can live in the room where people work.

The rest is straightforward: 3 HP on 230V single phase supply, 8.5 CFM at 150 psi with a maximum of 150 psi, an integrated air dryer, and a 60 gallon ASME/CRN tank. The range is produced in Italy by Atlas Copco, and the airend carries a 100% duty rating. A summary field on the listing rounds the output to 9 CFM; that is the same figure.

Why a 3 HP screw compressor exists at all

At this size, the obvious alternative is a piston compressor, and it will usually be cheaper. What it will not be is continuous. A piston unit is rated to run for a portion of each hour and to rest for the remainder; when the workload exceeds that rating the machine gets hot, the oil degrades, and its life shortens visibly. A 3 HP screw compressor removes that ceiling. It is designed to run without a rest period, so it is sized against the air you actually consume and nothing else.

That matters most in the applications where a small compressor runs almost all day at low flow — a dental or medical bay, a laser or plasma table's assist air, a laboratory bench, a small production cell, a tyre and service bay in a quiet unit. In those settings a piston compressor is being asked to do the one thing it is not rated for, and the noise it makes doing it is a second problem on top of the first.

Start/stop, not load/no-load, and why that is right here

The bigger machines in this range run load / no-load with a timed shutdown, because on a larger airend the cost of frequent starts outweighs the cost of running unloaded for a while. This unit uses start/stop operation instead. On a small screw compressor serving intermittent demand, stopping is the efficient answer: there is no point paying to spin an airend that is making no air. It is one of the small signs that this is a properly specified small machine rather than a large one scaled down.

Dry air from the first hour

The dryer is part of the machine, not a second purchase mounted next to it. That matters because at this size the add-on dryer is the component most often deferred and then never fitted, and the consequence arrives slowly — water in the tool, water in the control valve, water on the workpiece, corrosion inside equipment you never open. Having the drying built in and commissioned with the compressor removes the decision entirely. It also removes the most common small-system sizing error, which is a dryer chosen against the pipe size rather than against the compressor's actual output.

The tank, and what ASME/CRN means for you

The receiver is a 60 gallon ASME/CRN tank. ASME describes the pressure-vessel construction standard the tank is built to. CRN is the Canadian registration number system for pressure vessels — a tank carrying it has been registered for use in Canadian provinces, which is exactly the paperwork a Canadian inspector will ask for and which many otherwise-identical tanks do not have. If you are buying in the United States it costs you nothing; if you are buying into a jurisdiction that requires registration, it is the reason to choose this tank over another.

Will it fit, and will it run?

Supply is 230V single phase, so this is one of the machines in the range a building without three-phase service can actually use — but have an electrician confirm the circuit rather than assuming a spare outlet will carry it. Physically, allow for about 56.3 inches of length and roughly 452 lbs of weight; that is a pallet-jack move and a standard-door fit, not a two-person lift. The tank outlet is 1/2 inch. Give the cooler side real clearance, because the integrated dryer adds heat to the package. The listing also stores an overall width and height, but neither carries a unit, so we will not print them as though they were measurements — ask us and we will send the dimensioned drawing. Confirming supply, clearance, ventilation and floor loading before delivery is the buyer's responsibility.

Perfect for

• Quiet premises — showrooms, clinics, laboratories, workshops attached to offices — where 61 dBA is the specification that decides the purchase.
• Single-phase buildings that want continuous-duty air without an electrical service upgrade.
• Low-flow, all-day applications such as assist air, control air or bench work, where a piston compressor would be running outside its duty rating.
• Canadian installations where pressure-vessel registration is required before commissioning.

What is in the box

As stated on this listing: the 3 HP TEFC Baldor motor and airend, the integrated air dryer, the low sound enclosure, the start/stop control with an approved control panel, and the 60 gallon ASME/CRN tank. Downstream filtration, an automatic drain, valves, pipework and the electrical disconnect are not stated as included; treat them as your part of the installation unless we confirm otherwise in writing.

Specifications

Approvals, stated plainly

Here is exactly what this product's data does and does not claim. The control panel is described as UL and cUL approved. The tank is described as ASME/CRN. Those are two real, specific statements — one about the electrical panel, one about the pressure vessel — and between them they cover more ground than most compressor listings in this price range. What the data does not carry is any further third-party mark or agency listing, and we are not going to imply one by writing vaguely about the machine being "fully certified". If your insurer, your jurisdiction or an internal safety programme needs documentation beyond the panel approval and the vessel registration, ask us before you order and we will request it from the manufacturer in writing.

Shipping and delivery

Palletised freight to the lower 48 states, free of charge. Roughly 452 lbs has to come off the truck, which means a forklift, a dock, or a collection from the carrier's terminal — the last of which is a perfectly ordinary choice for a small shop or a clinic with no loading facilities. Residential deliveries carry a residential fee. Inspect the machine before you sign: on an enclosed unit the enclosure panels and the cooler are what get damaged, and damage under a panel is easy to miss, so look properly and note anything at all on the bill of lading while the driver is present.

Warranty

This listing states one term only: 5 years, available where the machine receives an authorized start-up, and it asks you to contact us for the detail. We would rather reproduce that accurately than invent a standard period the page does not state — so if you want the cover confirmed in writing before you buy, ask and we will get it. What we can tell you without qualification is the thing that voids a claim faster than anything else: do not open the airend, the dryer circuit or the control panel before a claim has been raised. A machine that has already been dismantled is close to impossible to claim on.