Vertiv Liebert AFC

Adiabatic freecooling chiller with evaporative pre-cool, free-cooling coil, and screw or scroll backup compression

Vertiv Liebert AFC is one of 5 chillers tracked in the SecondWatt catalogue, each with specifications, lead times and indicative secondary-market pricing.

Chilled water is only the upstream half of a high-density cooling loop: once heat is picked up at the die rather than in the room, the plant feeds coolant distribution units and immersion tanks tracked under liquid cooling, which run off the same chilled-water supply as the units on this page. The catalogue entries closest to that decision are ZutaCore HyperCool Two-Phase Immersion and GRC ICEtank Immersion Cooling.

Vertiv Liebert AFC adiabatic freecooling chiller: verified capacity, refrigerant GWP by series code, water consumption findings, and inspection checklist.

Why it matters

The AFC's efficiency comes from evaporating water, and Vertiv publishes irrigation and bleed-off flow but no nameplate net water consumption for any frame, so a buyer cannot size a water budget from the spec sheet alone. Water rights, discharge permitting, and makeup-water quality are therefore a go/no-go site screen that belongs before capital cost. Series code also decides refrigerant compliance: CH4/FH4/NH4 predates the EPA's 700 GWP limit, while CH3/FH3, CIZ/FIZ, and R-515B clear it.

Who buys it

Hyperscale, colocation, and cloud operators specify Liebert AFC for chilled-water plants without a condenser-water loop, especially for high-density GPU clusters and hybrid liquid-cooling facilities. Enterprise and telecom operators select smaller frames from the same series for comfort cooling. A buyer should read the series code off the nameplate, since CH4/FH4/NH4 units still carry the legacy R-134a refrigerant newer CH3/FH3 and CIZ/FIZ frames replaced.

Key specifications

Technical summary

Capacity, current global range: 877-2,025 kW (up to 2,200 kW single-frame) Capacity, current global range: 249-576 tons (up to 626 tons) [derived, 1 ton = 3.516853 kW] Three-stage cooling: adiabatic pre-cool pads, then free-cooling coil, then screw/scroll compressor back-up Refrigerant by series: R-134a (CH4/FH4/NH4), R-513A (CH3/FH3), R-1234ze(E) (CIZ/FIZ), R-515B (NA launch option) Full-load EER: 13.2-14.7 Btu/(W-h) US convention; 3.84-5.52 kW/kW EU convention Adiabatic pad irrigation flow: 76-152 L/min by fan count (10-20 fans) Adiabatic bleed-off default: approximately 10 percent of total irrigation flow Sound level: 67.5-83.1 dB(A), ultra-silent to standard configuration Electrical supply: 400V/3ph/50Hz (EU/EMEA) or 460V/3ph/60Hz (North America) Minimum ambient operating temperature: -25°C to -10.5°C depending on frame and refrigerant

Configurations and options

Compressor architecture is a build-time choice between fixed-speed screw, full-inverter screw, and a smaller-frame scroll configuration. Electrical supply is regional: 400V/3ph/50Hz for EU/EMEA-built units and 460V/3ph/60Hz for North America-built units. Sound packages range from a standard 73.5-83.1 dB(A) tier to an ultra-silent 67.5-69 dB(A) option, and the adiabatic pre-cooling stage itself is the line's defining configuration choice against a plain free-cooling chiller.

Compatibility and dependencies

The adiabatic stage is the compatibility gate: a site needs a continuous make-up water supply meeting Vertiv's hardness (20-100 mg/L CaCO3) and total-dissolved-solids (under 450 mg/L) specification, plus a discharge path for bleed-off water, before the unit can run adiabatically at all. Water rights, discharge permitting, and metered water cost are therefore a go/no-go site screen that belongs before capital cost, since Vertiv publishes irrigation and bleed-off flow rates but no nameplate net-consumption figure a buyer can size a water budget against. Electrical nameplate voltage and frequency (EU 400V/50Hz versus North America 460V/60Hz) and minimum ambient rating must also match the destination site before a cross-region relocation is assumed straightforward.

Pricing and availability

Trend: flat

Common failure points

• Adiabatic pad media — scale crust and uneven wetting reduce evaporative pre-cooling delta-T, forcing earlier and more frequent compressor engagement
• Microchannel aluminum coil — corrosion or pitting leading to refrigerant leak; an aluminum microchannel coil cannot be spot-repaired tube-by-tube like copper fin-and-tube
• Irrigation pump, solenoid, and nozzles — scaling or clogging cuts adiabatic pre-cooling effectiveness, silently shifting more load onto compressors without an obvious alarm
• Screw or scroll compressor — bearing wear and valve-plate damage accumulating from repeated hybrid-mode cycling rather than steady full-load running
• Liebert iCOM control board — an obsolete hardware or firmware revision cannot receive current Vertiv updates or integrate cleanly with a new site's building management system
• EC fan motors — bearing wear and vibration from constant speed-modulation duty across hybrid-mode operation
• Cabinet and frame corrosion near adiabatic section — structural steel and drain-pan corrosion concentrated around the wetted pad zone, distinct from the dry sections of the cabinet

Inspection checklist

Adiabatic pad media and bleed-off setpoint — inspect the cassette for mineral scale crust and uneven wetting, and verify the bleed-off valve is field-set near the OEM's ~10% of total irrigation flow default, not bypassed or zeroed to cut water cost Makeup water hardness log — request history against the OEM's 20-100 mg/L CaCO3 total-hardness spec for the irrigation supply Makeup water TDS log — request history against the OEM's under 450 mg/L total-dissolved-solids spec Irrigation pump and manifold flow test — field-verify delivered flow against the OEM's 76-152 L/min table keyed to the unit's 10-20 fan count Free-cooling and condensing coil — pressure-test the full-aluminum microchannel coil, since it cannot be repaired tube-by-tube like a copper fin-and-tube coil, so any leak is a coil-replacement event Refrigerant charge and leak history — confirm nameplate refrigerant against the series code (R134a/R513A/R1234ze/R515B) and request leak-rate records if the charge exceeds 50 lb, since comfort-cooling equipment carries a 10% annual leak-rate repair trigger Compressor run-hour log by mode — request hours split between pure free cooling, hybrid, and full mechanical operation, since hybrid-heavy sites accumulate more compressor starts per calendar year than the raw hour count suggests Compressor type and count confirmation — verify screw versus scroll and inverter versus fixed-speed against the nameplate model code, for example CIZ, FH3, or CH4 Fast Start Ramp function test — confirm the unit restarts to full compressor capacity within the OEM's stated 70-second window after a simulated power interruption Liebert iCOM control board revision — record hardware and firmware revision and confirm current factory support status directly with Vertiv before purchase EC fan sample vibration check — test a representative sample of the unit's fan count, 10 to 20 fans depending on frame, for bearing wear Cabinet and frame corrosion — inspect structural steel and drain pan near the adiabatic pad section specifically, since this area sees continuous wetting a standard dry air-cooled chiller does not Glycol versus glycol-free loop confirmation — verify whether the unit is a standard 30% ethylene-glycol frame or an N-series glycol-free variant, and test glycol concentration against the buyer's freeze-protection requirement Electrical nameplate versus destination site — confirm 400V/3ph/50Hz or 460V/3ph/60Hz nameplate matches the buyer's site voltage and frequency before assuming a cross-region relocation is straightforward Minimum ambient rating versus destination climate — confirm the unit's rated minimum ambient, roughly -25C to -10.5C depending on frame and refrigerant, is adequate for the buyer's coldest design-day temperature