EVAPCO PHC-E Parallel Hybrid Evaporative Condenser

A hybrid condenser that pairs a wet coil with crossflow fill

The EVAPCO PHC-E, the Parallel Hybrid Condenser, is an induced draft evaporative condenser that combines a spray-wetted condensing coil with a crossflow PVC fill section below it. Hot gas from the compressor enters the coil at the top, water from the basin is pumped over the coil, and ambient air is drawn into the top of the unit in parallel flow with the water through the coil. Water that does not evaporate then falls through the fill, where additional air drawn through the side of the unit cools it before it returns to the basin. EVAPCO states the result is more capacity on a smaller plan area, with fewer motors, less weight and a lower refrigerant charge than other designs in its range.

The line is offered in S models, with a single coil, and D models, with double coils, and the bulletin lists 84 to 2,120 ammonia tons at standard conditions. EVAPCO positions it for large industrial refrigeration projects, where the plant designer needs flexibility in layout, fan motor size and number of cells.

Technical specifications

Model range and engineering data

The model code reads PHC, then S or D for single or double coil, then the box size and the rating in tons: PHC-S79-84E is a single coil unit on a 7 x 9 ft box rated 84 tons, and PHC-S1236-762E a 12 x 36 ft single coil unit rated 762 tons (derived from the printed headings and heater table; confirm on certified prints). Each box size is offered with several fan horsepower choices. Selected printed rows:

Each table also gives coil volume, spray pump horsepower and flow, remote sump gallons and connection sizes. The notes state that dimensions and weights are subject to change, that coil connection quantity and locations change with refrigerant loading, and that certified project prints must be used for piping.

Maintenance, winter and options

Large access doors let service staff enter the basin to adjust the float valve and inspect the unit, and a non-slip internal walkway is standard on double coil units. The field seam uses self-guiding channels and, according to EVAPCO, eliminates up to 85 percent of the fasteners normally used to join condenser sections, which reduces contractor labor and the risk of leaks. Optional equipment includes a self-supporting external platform with ladder, internal ladders, a motor davit, low sound and super low sound fans, and a Sun-Blocker system that stops sunlight and debris entering at the coil, fill and fan cylinder to limit algae.

For freezing weather the bulletin lists electric basin heater packages with thermostat and low water cutoff, sized by box size; a 7 x 9 ft box lists 6 kW at 0 F, 8 kW at minus 20 F and two 6 kW heaters at minus 40 F. External pumps should be heat traced and insulated. On 12 x 18 ft S models a dual 50 percent spray pump option increases water loading on the coil. Water treatment options are the Pulse-Pure chemical-free system and the Smart Shield solid chemical feeder.

Using the PHC-E in Oman and the GCC

Hybrid evaporative condensers are used in the region in industrial refrigeration plants such as cold stores, food and beverage plants and logistics centres, where lower condensing temperatures reduce compressor energy. The condenser must be selected at the project’s design wet-bulb temperature, which can be high in coastal summer conditions. For ammonia systems, the installation must follow the applicable refrigeration safety codes.

The spray water needs a water treatment programme, blowdown control and a Legionella control plan, as scale on the coil and fill reduces capacity. Dust and sand enter through the air inlets, so plan regular cleaning of the basin, strainers, nozzles and fill, and leave access space for maintenance.

Record condensing pressures and water readings at each service visit, so trends can be seen early.

Information to send with an enquiry

• Refrigerant and heat rejection capacity
• Condensing temperature and design wet-bulb temperature
• Make-up water quality
• Sound limits and quantity

Documents and quotation

The attached PHC-E bulletin contains the complete engineering tables and optional equipment data. Seven Star LLC is an independent supplier in Muscat; for a quotation provide the refrigerant, heat of rejection or compressor data, condensing temperature, design wet bulb and available plan area. More equipment is listed under cooling equipment.