Chilled Water Cooling Coil Selection

The extent to which coils raise the chilled water temperature dramatically affects both capital investment in chilled water piping and pumping power.

Chilled water cooling coil selection.

Evaluate water coil selection choices at various water temperatures and flow rates 4. In these cases the cooling coil cannot perform as much cooling. Coil performance can even influence the efficiency of the chiller. Chilled and hot water coils chilled and hot water coils are available in 1 5 8 1 2 and 3 8 inch od copper tubes with aluminum or copper fins.

Cooling coils are an integral part of the chilled water system too. On a cooling coil air velocities above 500 fpm is the point where water droplets can leave the outer edge of the fin. This allows the return water to temper the warmest entering air getting it closer to its set point prior to leaving the last row where it will see the coldest supply water temperature. With options that include copper fins and stainless steel casings our coil units help to power the broadest line of air handling systems in the industry.

Water coils need to be piped for counter flow with the return being on the entering air side of the coil and the supply being on the leaving air side of the coil. Typical chilled water coil 500 fpm. This is called moisture carry over. Casing options include flanged slip and drive end plates only and inverted side plate flanges in galvanized stainless steel and copper materials.

Standard and custom designs are available for new and retrofit installations. We design to avoid this. Rae coils is your one stop shop for everything coils. Whether it s a basic duct booster coil or a custom coil we can meet all of your specifications with accuracy ease and at a competitive price.

Most chilled water coils have air entering the system at a temperature ranging from 75 f to 95 f return or outside air while chilled water enters the coil at a temperature around 42 45 f. For example it was once common for chilled water to be 44 f supply temperature and 54 f return temperature. Chilled water cooling coil selection example 4 chilled water coil worksheet example 5 chilled water coil worksheet 6 enthalpy of air table 1 7 air density correction at altitude table 2 7 air density correction at temperature table 3 7 log mean temperature difference table 4 8 basic capacity figure 1 8fpi 9 basic capacity figure 2 1ofpi 10. The delta t was 10 degrees 54.

Understand the balance of coil face area airside pressure drop and waterside pressure drop when selecting a coil 5. We offer a complete line of hvac heating and cooling coils for all your replacement and new construction needs. Typical hot water coil 600 700 fpm. In many cases higher delta t results in a higher average temperature of the chilled water as it goes through the cooling coil at your load.

Chilled water coils typically consist of between 3 12 rows of tubes.