Chilled water coil,water coil, water coils, chilled water Water Coils can be used for a single purpose such as heating or cooling, or their function can be alternated between heating and cooling by changing the temperature of the water flowing through the coil. Depending on the application, it may be necessary to use a glycol mixture to prevent the liquid from freezing. Surefin water coils are engineered to operate at pressures up to 250 PSIG and temperatures up to 300°F, but ancillary equipment such as valves and umps will often dictate lower operating temperatures. All water coils are pressure tested at the factory with 450 PSIG of dry nitrogen.
Most chilled water coils are designed with either 1/2” or 5/8” O.D. tubes. However, there are an increasing number of manufacturers who design chilled water coils with 3/8” tubes, especially for coils that are for very low capacity (5 tons or less). Larger tubes are typically used because they keep the water pressure drop lower. However, the smaller tonnage coils usually have short tube lengths and, thus, inherently lower fluid pressure drops. The most commonly used tube material is copper, and there are a variety of tube wall thickness options to handle different applications. Aluminum is the most commonly used material for the fins on a coil, because of good heat transfer characteristics and low cost. There are many different fin designs that will either enhance heat transfer or reduce air pressure drop, depending on the requirement. Coil frames (or casings, flanges, whatever you might call them) are normally galvanized but stainless steel is a good consideration to increase the longevity of the chilled water coil. Coil connections are typically copper, brass, or steel.
Water coils are designated as chilled water coils when they are three thru ten rows deep. Again, most chilled water coils have an entering air temperature of 75° F to 95°F with a chilled water entering in the range of 45° F. As you can easily see, the spread between the entering water temperature and entering air is much closer than the hot water coil. When you factor in that the required leaving air might be close to 55° F, then you can see how close the temperatures become. You clearly need more rows to handle the load. In addition, you are dehumidifying and have a latent load to handle as well.
Ideal for a wide variety of basic, custom, and heavy-duty industrial applications, chilled water coils are designed to meet a variety of heating needs. Surefin can supply them with any design configuration to meet any application needs.