Chilled water coils are one of the most common mediums for cooling air. As warm air passes across the coil and comes in contact with the cold surface of the fins, heat then transfers from the air to the water flowing through the tubes both cooling and dehumidifying the air.
Depending on how much cooling is needed, chilled water coils are usually manufactured with anywhere between three and twelve rows of tubes. These tubes generally pass through sheets of formed fins, bonded through tube expansion. Commercial Coils can supply water coils with various tube, fin and material options.

Chilled or Hot Water Coil Specifications

Primary Surface


Round seamless copper tubes are mechanically expanded into the fin collars of the secondary surface. The mechanical expansion provides a permanent metal-to-metal bond for efficient heat transfer. Tubes are staggered in the direction of airflow and only return bends are used – NO reduced tube wall in the bend radius by using hairpin bends.

5/8″ O.D. x .020″ wall thickness standard with optional wall thickness of (.025) (.035) and (.049). Centerlines are 1.5″ in the tube face and 1.299″ between rows.

1/2″ O.D. x .017″ wall thickness standard with optional wall thickness of (.025). Centerlines are 1.25″ in the tube face and 1.083″ between rows.

3/8″ O.D. x .016″ wall thickness standard with optional wall thickness up to (.035). Centerlines are 1″ in the tube face and .866″ between rows.

Rows available are 1, 2, 3, 4, 5, 6, 8, 10 and 12.

We have over 20 different surfaces available. Please contact us if construction other than what is above is needed.

Secondary Surface


Corrugated plate type fin that is die-formed. Fin collars are full-drawn to provide accurate control of fin spacing and maximum contact with tubes.

5/8″ tubes comes standard with aluminum fin .008″ thick with optional (.010). Optional copper fin thicknesses available are (.006) (.008) and (.010). Fins per inch available 6 through 14.

3/8″ tubes comes standard with aluminum fin .0055″ thick with optional thicknesses available. Copper fin thicknesses available start at .0055″.

Fins per inch available 6 through 16.

Contact us for availability of other patterns, fin materials, and/or thicknesses.


Seamless copper with die-formed holes that provide a parallel surface to the coil tube for strong brazing joints. Standard 1/8″ brass female pipe thread (FPT) vent and drain with optional (1/4) and (3/8). All circuiting is designed to gravity-drain with the coil mounted vertically and tubes running horizontally.

Red Brass Schedule 40 male pipe thread (MPT) is standard with optional copper female pipe thread (FT) available.

Using 16-gauge minimum thickness material, 1 1/2″ flanges are die-formed to permit easy stacking and mounting. Intermediate tube supports are supplied on coils over 44″ fin length with an additional support every 42″ multiple thereafter.

Full G-90 galvanized steel standard with optional stainless, aluminum and copper.

Testing & Performance

All coil assemblies are leak tested under water at 315 PSIG air. Standard construction is suitable for 250 PSIG and up to 300 degrees F.

PERFORMANCE IS CERTIFIED under ARI Standard 410. All coil performance ratings are according to Commercial Coils, Inc.’s ARI certified selection software.