Condensate Recovery Tank Data Center: Capturing Coil And AHU Condensate

A condensate recovery tank for a data center collects the near-distillate water that forms on cooling coils and air-handling units, holds it as a clean, low-mineral reserve and returns it to cooling-tower makeup to offset potable draw. The recoverable volume is a function of coil load, entering-air humidity and runtime, and it is surprisingly large on humid sites. Because condensate is near-distillate quality, the tank and its distribution must avoid recontamination, and the internal finish must resist the mild but persistent corrosion that even clean condensate can drive on bare steel. NOTE: Center Enamel already publishes a dedicated page on this exact topic; this article is part of a user-requested full-15 batch and should be consolidated with or canonicalized to that existing page rather than published as a competing standalone URL.

Condensate is generated wherever humid air meets a surface below its dew point, and a data center has those surfaces in every computer-room air conditioner and air-handling unit. The primary and largest source is each CRAC or CRAH coil, proportional to its sensible and latent load and the entering-air humidity ratio. AHU and humidifier proximity drains and minor chilled-water loop drip add to the recovery header. The cleaner the collection - dedicated, covered drains rather than a shared floor sump - the less pretreatment the tank needs.

• CRAC or CRAH coil drains are the largest source.
• AHU and humidifier proximity drains add volume.
• Chilled-water loop drip is minor but collectible.
• Dedicated covered drains reduce pretreatment.

Water stored for reuse, process or fire duty spends most of its life idle, so the internal finish decides reliability more than the shell rating. Glass-Fused-to-Steel panels are fired at 820-930 °C to give a smooth inert skin at 0.25-0.45 mm thickness, adhesion above 3,450 N/cm2 and 100 percent 1,500 V DC spark testing per panel. Fusion-Bonded Epoxy bolted tanks (Resicoat R4-ES interior 180-280 micrometres, Interpon D2015 exterior 150-250 micrometres, adhesion above 16 MPa) and hot-dip galvanized bolted tanks cover specified or cost-sensitive duties. Stainless 304 or 316 is chosen where the recovered water is low-mineral and a factory vessel is preferred. A caveat applies: the right lining depends on the recovered-water chemistry, so the engineer should confirm pH and halide load rather than assume one coating fits every reuse stream.

• GFS bolted: inert enamel, Ra below 0.8 micrometres, no field recoating.
• FBE bolted: documented epoxy lining for specified duty.
• Hot-dip galvanized: lower cost, zinc shell protection.
• Stainless 304 or 316 for low-mineral recovered water.

Sizing starts from the actual duty calculation - rainfall capture volume, cooling-makeup balance, greywater generation rate or fire hydraulic demand - not a catalogue number. The coating thickness of 0.25-0.45 mm for GFS or 180-280 micrometres for FBE, the tank lifecycle of 30-50 years, the NSF/ANSI 61 or WRAS potable-contact option and the freeze or tropical duty margin then set the shell, roof and appurtenances. Every figure below is confirmed against the applicable standard and the local authority having jurisdiction.

The figure below is a REAL Center Enamel delivery used here as manufacturing-capability evidence for the tank type discussed, NOT as a claimed data-center, rainwater, greywater, reclaimed, condensate or ice-storage project. Center Enamel's verified project record (case_library.csv) holds no data-center water-reuse, greywater, reclaimed-water, condensate-recovery or ice-storage delivery, so this reference demonstrates the ability to engineer large coated and stainless water tanks for demanding duty, not a claim about this specific application. Where the source did not record a diameter or height, the field reads Not Provided and is never estimated.

Estimate the recoverable volume from the coil latent load expressed as water, scaled by runtime and climate, then size the tank for the steady-state average plus a band for peak humid periods. Keep the condensate loop isolated from potable by air-gap or backflow protection, and select a finish - GFS enamel or passivated stainless - that resists the low-mineral water without recontamination. Confirm the collection path is clean before the water reaches the tank.

• Estimate from latent load and climate.
• Size for average plus peak-humid band.
• Isolate condensate from potable by air-gap.
• Select GFS or stainless to resist clean water.

A reserve that collects near-distillate water from cooling coils and AHUs and returns it to cooling-tower makeup, offsetting potable draw.

From the coil latent load expressed as water - airflow times the humidity-ratio drop - scaled by runtime and the annual humidity profile, not a single design day.

It condenses from humid air with almost no dissolved solids, so it is clean but also aggressive to bare steel and must be protected from recontamination.

GFS enamel resists the mild corrosion clean condensate drives; passivated stainless 304 or 316 is chosen where the volume is modest and a factory vessel is preferred.

Typically minimal - screening and perhaps disinfection - because the source is clean, provided the collection path uses dedicated covered drains.

Yes - a dedicated condensate recovery tank page exists on the company site; this article should be consolidated with or canonicalized to that page rather than published separately.

By returning clean coil water to makeup, the data center lowers annual potable withdrawal and improves its Water Usage Effectiveness metric.

No - the fire reserve is a separate code-referenced volume and must stay isolated from the condensate loop.

AWWA D103-09 and ISO 28765 for the bolted structure, with NSF/ANSI 61 or WRAS available where recovered water contacts potable-adjacent systems.

About 30 days ex-works for a 1,000-10,000 m3 tank, with on-site bolted erection in weeks versus months for concrete.

A verified single shell of 20,000 m3 was delivered in 2016, establishing the upper bound for one bolted tank.

A sealed, covered roof keeps the near-distillate water from picking up dust and biological load, preserving its quality before reuse.

Yes - the lining, not only the steel, should be warranted, because clean-water duty stresses the coating over a 30-50 year life.

Periodic internal inspection of the lining and verification of the collection path support a 30-50 year service life.

Yes - the design must balance volume so the tank captures peak humid recovery without overflowing, while still covering dry periods.

A data-center condensate recovery tank captures near-distillate coil and AHU water and returns it to cooling-tower makeup, lowering Water Usage Effectiveness with one of the highest-return recovery moves available. The psychrometric volume, inert or stainless finish and clean collection path decide whether the condensate is actually captured, and those figures must come from a latent-load and climate calculation rather than a guess. (This article duplicates an existing company page and is flagged for consolidation or canonicalization.)