Guide Specs

SERIES 77 STEAM UNIT HEATER SK-880-77 NOVEMBER, 1997

The Steam Unit Heater shall be manufactured by Hartzell Fan, Inc.® and identified as Series 77. The design shall be classified as a horizontal airflow, blow-through configuration. The design shall be an assembly consisting of an electric motor direct connected to a propeller fan and a housing containing a steam-to-air heat exchanged. Twenty-four models, ranging from 12" to 28" fan diameter, shall be available to provide heating capacities of 31,000 Btuh to greater than 524,000 Btuh (using 5 psig saturated steam with 60° F. entering air temperature) from 600 to 9000 SCFM of airflow, respectively.

The fan shall be an airfoil type propeller design, cast of 319 aluminum alloy complying with Federal Specification QQ-A-601E and ASTM B26. The propeller shall be retained on the motor shaft utilizing a split taper bushing or a clamp block arrangement. The fan motor shall be a totally enclosed air-over type with permanently lubricated bearings. A motor mounting frame composed of a steel motor base and solid steel support rods shall be provided. An inlet orifice ring is to be provided, enclosing the propeller at the entrance to the coil housing.

The heat exchanger shall be either a 1-row deep (Series 771) or a 2-row deep (Series 772) coil. The coil shall be composed of finned-tube type elements attached to steel headers with integral threaded inlet and outlet pipe nipples. The finned-tube type elements shall consist of helical copper fins, solder coated (14 per inch spacing), and mechanically secured to seamless copper tubing. Tubing to header joints shall be high temperature silver brazed. Coils are to be rated for steam up to 200 psig and 400° F.

The coil housing shall be formed from 16 gauge, hot rolled, low carbon steel sheet. Each housing shall be provided with two mounting points, consisting of 1/2"-13UNC machine screw nuts welded to the inside of the inlet end of the housing. The housing will incorporate manually adjustable louvers over the outlet face of the steam coil. Corrosion protection will be furnished by a phosphatized surface preparation with an application of industrial air-dry enamel paint over the housing and motor mounting frame.

Fans shall be balanced in accordance with AMCA Standard 204-96, fan application category BV-3 (comparable to Grade G6.3). Fan performance shall be based on tests conducted in accordance with HartzellÕs AMCA accredited test laboratory in accordance with AMCA Standard 210 for air and AMCA Standard 300 for sound.