The heating range of model WS is 13,000 to 350,000 BTUH.  The air volume ranges from 270 to 4,750 CFM.  The heat exchanger is made of one or two rows of copper coils with aluminum fins, with approximately 10-1/2 fins per inch (4 fins per cm).  The spacing between the fins makes cleaning and maintenance of the heat exchanger easier, which is essential to keep the unit heater efficient.

The copper tubing used for the heating coil is very thick (0.03",0.75 mm), making Reznor heating coils extremely sturdy and long lasting.  The copper tube diameter is 0.867" (22 mm) O.D.  The large tube diameter reduces the water pressure drop, which means these units require lower pump pressure than other hydronic heaters.  It also allows a very rapid heat radiation.

The heat exchanger assembly receives a special paint coating which makes the coil long lasting and increases the thermal output.  Reznor® model WS can be used with a high working pressure with hot water up to 150 psi and with steam up to 145 psi (10 bar).  Every heat exchanger is subjected to a pressure test at over 350 psi (25 bar) before leaving the factory.

The fan/motor assembly is made up of three components: the fan, the motor and the fan guard, which also acts as the main support for the fan.  This fan guard is galvanized for protection against corrosion, and is mounted onto the main casing with anti-vibration rubber mountings.

The standard 2-speed motor is a hermetically sealed motor which is maintenance free.  The motor is wired for 115/1/60 supply voltage.  The motor speed is field adjustable to run at high or low RPMs.  Refer to the Technical Data chart for fan RPM, heating output and CFM ranges.

The flexibility of changing motor speeds allows the installer to adjust the unit to high speed for increased BTUH output or low speed for reduced noise level.  An optional three phase motor can be factory installed (208/230/460).  All motors have internal protection as a standard feature.  Explosion-proof motors are also available.  All model WS units can be installed for either vertical or horizontal discharge.

The unit cabinet is manufactured from .032" (0.8mm) galvanized pre-painted steel finished in dove gray.  Using pre-painted steel helps protect the cabinet against oxidation.  The cabinet is held together by shake-proof screws and molded corner sections to add additional strength and durability.  Adjustable louvers are held in place by spring loaded pivots.  Vertical louvers are available for field installation.  Optional overhead door diffusers are available on size 300/350.  This option allows the unit to be installed over loading dock doors maintaining a warm air curtain where it is needed most.  The optional air flow induction optimizer is available for horizontally discharged units.  The air flow induction optimizer increases the air flow due to the unique shape of its deflecting louvers which improves the throw of the heated air stream.  See the optional accessories section for more information.  Units are packaged into strong corrugated cardboard cartons with strengthened upper and lower side sections.  These containers are clearly marked with the model number, size and approximate shipping weight.