Atlas Copco ZR 45 VSD (FF VSD⁺) Oil-free Tooth Air Compressor

The Atlas Copco ZR 45 VSD is the water-cooled 45 kW (60 hp) member of the ZR/ZT 45 VSD+ oil-free tooth platform, and on the ZR side the variable-speed range is published only as the VSD+ tier — there is no separate standard VSD row for the water-cooled 45. It drives both the 8.6 and 10 bar(e) classes from one 45 kW motor, and because the heat is rejected to water instead of air, the machine carries no axial fan and lists a work-station noise of 67 dB(A). For a plant that already runs a cooling-water loop, that layout turns compression heat into a recoverable stream rather than room load.

Two Pressure Classes on the Water-Cooled 45 kW Frame

The ZR 45 VSD range prints both classes from one drive, and the water-cooled side is the only variable-speed 45 on the ZR branch. At Minimum the 8.6 bar(e) class opens at 4 bar(e), or 58 psig, with 37.8–130.6 l/s, and at the Effective point of 7 bar(e) it reads 37.1–129.00 l/s; the Maximum row at 8.6 bar(e) closes at 37.02–114.1 l/s. The m³/min band runs 2.2–7.8 at Minimum and the sound pressure level for the whole machine is listed at 67 dB(A).

8.6 bar(e) Class of the ZR 45 VSD+

Read the 8.6 bar(e) class from the top of each row: the upper flow edge drops only from 130.6 to 114.1 l/s across the whole pressure travel, a band of 16.5 l/s, while the m³/min column narrows from 2.2–7.8 to 2.2–6.8. A header regulated near 7 bar(e) is sized against the Effective row at 129.0 l/s, and a line working close to rated pressure reads the Maximum row, where the lower edge still holds 37.0 l/s. The ZR 45 VSD keeps the same flow envelope at Minimum whether the class is 8.6 or 10 bar(e), because one drive covers both.

10 bar(e) Class of the ZR 45 VSD+

The 10 bar(e) class adds the higher pressure band, and it opens at the same Minimum row because the drive shares one flow envelope. At Minimum it reads 37.8–130.6 l/s and the Effective row at 9 bar(e) reads 36.2–108.8 l/s; the Maximum row at 10 bar(e), or 145 psig, closes at 36.03–95.7 l/s. Here the m³/min band narrows from 2.2–7.8 to 2.1–5.7, the flow a plant gives up for the extra pressure headroom on the same 45 kW motor that the ZR 45 VSD carries.

Energy Recovery Turns Compression Heat into 90°C Water

The ZR 45 VSD offers an Energy Recovery control-unit option that captures heat from the water-cooling circuit and returns it as up to 90°C water for process or space heating. In a water-cooled machine the rejected heat is already in the loop, so the recovery path needs no separate air-handling step, and the recovered stream can offset boiler load in a nearby circuit. A plant metering its steam or hot-water demand should size the recovery option against the hours the compressor actually runs, because the recoverable energy scales with duty.

Weights, Dimensions and Dryer Builds of the ZR 45 VSD

The ZR/ZT 45 VSD+ frame measures 2005 × 1022 × 1909 mm as a pack and 2440 × 1022 × 1909 mm as a Full Feature build. The data sheet prints three weights — pack 1373 kg, Full Feature with iMD 1646 kg and Full Feature with iD 1531 kg — and the integrated dryer adds to the standard figure when it is ordered. The water-cooled side shares these dimensions with the ZT 45 VSD+ of the same platform, so the bay floor is planned the same way for either cooling path.

Sizing a Water-Cooled 45 kW Installation

Water cooling moves the placement decision to the loop: the ZR 45 VSD rejects heat into the cooling water, so it suits plants with a tower or plate exchanger, and it removes the axial fan the air-cooled tier would carry. The 67 dB(A) is the A-weighted sound pressure level at the work station measured under ISO 2151:2004 with the KpAd correction, and the CAGI performance sheets list the drive as 40.2 and 40.2 hp at 96.3 percent efficiency with no fan motor on the water-cooled side. A plant comparing the ZR and ZT 45 VSD tiers should weigh the recovered-heat value of water cooling against the simpler hookup of air cooling before fixing the cooling path.

Questions Buyers Ask About the ZR 45 VSD

Why is there no standard VSD row for the water-cooled 45? The ZR side of the 45 kW point is published only as the ZR 45 VSD+, so the water-cooled 45 has no separate standard VSD line the way the air-cooled ZT45VSD does. The VSD+ tier already carries both 8.6 and 10 bar(e) classes, so a single published row covers the pressure range most plants need.

What can the 90°C recovered water feed? The Energy Recovery option returns heat as up to 90°C water, which a plant can route to process heating, space heating or a clean-in-place circuit instead of venting it. The recovery is tied to the cooling loop, so it pays back fastest where hot water or steam is already metered and where the compressor runs long hours.

How does 67 dB(A) compare with the air-cooled tier? Both values are sound pressure levels at the work station with the KpAd correction, and the ZR 45 VSD prints 67 dB(A) against the 68 dB(A) of the air-cooled ZT45VSD+ and the 78.5 dB(A) of the standard ZT45VSD. The lower figure comes from dropping the axial fan, which also removes a parasitic load from the drive.

From the ZR 45 VSD to the ZR 50 VSD+

When demand outgrows the 130.6 l/s top edge of the ZR 45 VSD+ 8.6 bar(e) class, the next step in the oil-free line is the Atlas Copco ZR 50 VSD⁺, whose 8.6 bar(e) class spans 37.5–147.7 l/s at its Minimum point on a 50 kW motor. Sending the measured demand profile of your header with the enquiry lets the quotation land on the model and class that actually matches the plant.