Guide Specs
Series SAH, Steam Make-Up Air Heater, Face-and-Bypass Type, Axial, SK-880-87, Nov 1997
The Steam Make-Up Air Heater, Face-And-Bypass Type, Axial shall be manufactured by Hartzell Fan, Inc. and be identified as Series 87. The design shall be classified as a draw-through type, indoor or outdoor (with minor modifications), packaged configuration for horizontal installation. Units shall be a modular assembly consisting of a fan section, an optional filter section, and a heating section. The fan section shall contain an electric motor powered, belt driven, duct axial fan. The filter section shall contain a framework supporting reusable or throwaway type air filters. The heating section shall be a mixing plenum with the plenum inlet divided into two sections: heated and unheated. The heated section shall be equipped with a steam-to-air heat exchanger downstream of a motorized damper. The unheated section shall be equipped with a motorized damper only. A control system to activate/deactivate the unit, modulate the outlet air temperature, and protect the integrity of the coil shall be furnished. Forty models shall be available providing 741,000 to 3,970,000 Btuh of heating capacity (using saturated steam at 5 psig with an entering air temperature of 0° F.) from 8,000 to 45,000 SCFM of airflow, respectively, at 0 to 1.0 in. W.G. external static pressure.
The duct axial fan propeller shall be an airfoil design, 6 bladed, one piece construction cast of 319 aluminum alloy in compliance with Federal Specification QQ-A-601E and ASTM B26. Bearings shall be heavy duty, self aligning, ball or roller type; depending on fan size, motor horsepower, and performance specified. Bearings shall be equipped with extended lube tubes. Drive belts which are over sized for continuous service and are heat, oil, and static resistant shall be supplied.
The steam-to-air heat exchanger shall be a non-freeze type coil design incorporating finned-tube type elements each having tube within a tube construction. The finned-tube elements will consist of 5/8 inch O.D. x 0.025 inch copper outer tubes with helically wound, mechanically bonded aluminum fins, spaced 10 per inch. The coil shall be composed of horizontal rows of finned-tubed elements, two deep, attached to vertical steel headers with integral threaded inlet and outlet pipe nipples. A 16 GA galvanized steel casing shall support the assembly and rest on rails within the housing to facilitate coil removal.
The housing will be formed of heavy gauge welded, hot rolled, low carbon steel sheet. Construction shall be modular incorporating bolted and gasketed reinforced flanges at joints interconnecting sections of the housing. The housing shall be protected from corrosion by an application of an industrial air-dry enamel paint. The plenum shall be provided with two independent, motorized, center pivoted, control dampers and an access door.
An electromechanical control system with a NEMA 4/12 control cabinet shall be furnished. A discharge air temperature sensor and an outdoor air temperature compensating controller will control the modulation of the two independent damper motors. A low temperature safety shutdown thermostat; a two-position steam control valve; a magnetic, full voltage, fan motor starter; a control transformer; fuses and fuse blocks; and terminal strips shall be provided. A remote operating station with indicating lights shall also be included.
Fans shall be balanced to the American National Standards Institute, Std. S2.19-1989 “Balance Quality of Rotating Rigid Bodies”, Grade G6.3. Fan performance shall be based on tests conducted in Hartzell’s AMCA accredited test laboratory in accordance with AMCA Standard 210 for air and AMCA Standard 300 for sound performance.
ACCESSORIES:
Heavy Duty Coils - Longer life, Cupro-Nickel coils available for 75 psig and above steam pressures.
Room Thermostat - Automatic, remote room temperature control.
Service Platform - Raised flooring for maintenance and service.
Turning Elbow - Duct which redirects airflow 90°.
Filter Box w/Filters - Housing supporting reusable or throwaway type filter elements.
Recirculated Bypass Section - Louvered ductwork which allows reheating of room air.
Two and Four-Way Outlet Diffusers - Adjustable louvers providing directional control of discharge airflow.
JIC Disconnect Switch - Safety device which de-energizes unit without opening control cabinet.
Inlet Weatherhood - Downward turned elbow which minimizes entrainment of snow and rain.
Combination Motor Cover/Belt Guard - Enclosure providing increased weather protection for motor and operator safety around moving equipment.
Special Motors - Special constructions or manufacturers models furnished upon request.
Discharge Straightening Vane Section - Ductwork which promotes recovery of energy, in the form of static pressure, normally lost in the discharge airflow whirl.
