EVAPCO EAW-VD V-Coil Dry Cooler

A V-coil dry cooler that rejects heat without spraying water

The EVAPCO EAW-VD is the V-coil arrangement of the eco-Air dry cooler line. Process fluid flows inside finned coil banks and fans draw ambient air across them, so heat leaves as sensible heat only and there is no spray water, basin or fill. The two coil banks form a V, which EVAPCO lists as maximum surface area per footprint.

The EVAPCO bulletin shows the VD range covering roughly 13 to 415 nominal tons on one page of its capacity overview. That span runs from a single-fan unit to multi-fan, multi-bay units, so one family can serve small process loops and large plant circuits.

Technical specifications

Selected engineering data

The bulletin lists every VD model with fan count, capacity, motor power, air flow, length, coil volume and weights. These four rows show the spread from the smallest model to the largest. Moving from one fan to twenty, capacity climbs from 207 to 4,461 MBH, connected fan power from 4.3 to 85.8 hp, and the operating weight from 1,810 lb to 22,410 lb. Longer units therefore need a proper structural check, and the largest printed length of almost 40 ft calls for planning of the lift and the delivery route.

Several VD models are offered with either EC or NEMA motors, so confirm the motor type with the model code when ordering. Lengths and weights follow the printed table. Operating weight includes the fluid held in the coil volume shown, which is worth remembering when the support frame is designed.

Construction, motor options and selection

In the V-coil group EVAPCO stresses the most surface area for the floor space used, a coil angle tuned for heat rejection and airflow, and a compact plan layout. Tubes are 304L stainless with aluminum fins, offered in several fin spacings and tube layouts, with a thicker fin as an upgrade. An epoxy fin coating can be added to dry units for corrosion resistance and, per the bulletin, leaves capacity unchanged.

Removable inspection panels open up the interior for checking the coils and fan motors, and return bend covers guard the coil bends while the unit is moved and operated. A step deck is optional inside the 7 ft 9.75 in wide V-coil units, giving a platform and grab rail to reach the raised fan section.

Fans can be specified with EC motors (high efficiency, no maintenance, built-in speed control, naturally quiet) or with NEMA motors (premium efficient, direct drive, sealed bearings, VFD ready, severe duty). The choice also decides the control package: a PLC panel for EC and a PLC with VFD panel for NEMA.

A dry cooler works with air only, so the leaving fluid stays above the entering dry bulb temperature. To match coil and fans to the duty, state the fluid, any glycol percentage, flow, in and out temperatures, and the design ambient.

The eco-Air Series carries CTI Standard 201 thermal certification, a scheme extended to dry coolers in 2022. Adiabatic (EAW-VA) and spray (EAW-VS) versions of the V-coil family exist too; only the dry EAW-VD is described here.

Coils arrive nitrogen charged to protect the tubes. Allow for draining and venting in the pipework, and check the fluid pressure drop for the chosen circuiting. Where the building code treats the plant as essential, note that the bulletin gives IBC compliance with shake table verification for the 1.5 importance factor.

Using the EAW-VD in Oman and the GCC

Dry coolers are used in the region where water is scarce or costly, or where water treatment and Legionella control should be avoided, for example in data centres, power generation equipment, compressor and engine cooling, and process cooling in remote locations. Because a dry cooler rejects heat only to the air, the leaving fluid temperature can never be lower than the ambient dry-bulb temperature, and summer dry-bulb temperatures in the region can be very high. The selection must therefore be made at the project’s design dry-bulb temperature, and the process must accept a leaving fluid temperature above that value with a suitable approach.

Where lower fluid temperatures are needed on the hottest days, a dry cooler may be combined with a chiller or another cooling method, and this should be considered at the design stage. Dust and sand collect on finned coils and reduce capacity, so plan regular coil cleaning with methods that do not damage the fins, and consider fin coatings for coastal sites with salty air. Leave enough free space around the unit for the air supply, and avoid locations where hot exhaust air from the unit or nearby equipment can be drawn back into the coils.

Information to send with an enquiry

• Fluid, glycol content, flow rate and temperatures
• Design dry-bulb temperature
• Sound limits and site layout
• Motor and control options and quantity

Related EVAPCO products: EVAPCO PHW Parallel Hybrid Closed Circuit Cooler, EVAPCO AXS Advanced Crossflow Induced Draft Cooling Tower, EVAPCO LPT Low Profile Centrifugal Fan Cooling Tower, EVAPCO ATWB Induced Draft Closed Circuit Cooler, EVAPCO PHC-E Parallel Hybrid Evaporative Condenser and EVAPCO ATC-E Induced Draft Evaporative Condenser.

Documents and quotation

The attached bulletin covers the whole eco-Air series including the engineering tables. Seven Star LLC is an independent supplier in Muscat; send the duty, fluid, ambient and fan preference for a quotation. See also cooling equipment.