Guide Specs

SERIES GFC DIRECT GAS FIRED MAKE-UP AIR HEATER, FORWARD CURVED TYPE SK-880-GFC NOVEMBER, 1997

The Direct Gas Fired Make-Up Air Heater, Forward Curved Type shall be manufactured by Hartzell Fan, Inc.® and identified as Series GFC. The design shall be classified as a draw through type. The unit shall be built in pre-engineered modules for ease of transportation, installation, and maintenance. Modules shall include a fan section, heating section with birdscreen and an optional filter section. The modules shall be built in heavy duty G-90 galvanized steel housings constructed of 16 gauge minimum material, reinforced with self-formed integral flanges and structural bracing to strengthen and support the unit. Roof surfaces shall be pitched to prevent accumulation and penetration of water. Modules shall be connected with standing seam construction complete with weather seals. Units shall be designed to produce (200,000 - 9,788,850) BTU per hour heating capacity, (2,000 to 75,000 CFM) SCFM of airflow, pressure capabilities shall be at 0" - 2.5" ESP. Unit shall be designed for (horizontal/vertical) installation.

The fan section shall include a class I forward curved DWDI centrifugal fan. Fan shall be arrangement #3 with motor mounted on an adjustable base. Fans shall be dynamically balanced and will be tested for air and sound performance in an AMCA registered test facility, in accordance with AMCA standard 210 and 300, respectively. Motors shall be located in the airstream and shall be OEDP 1.15SF type. Fans shall be belt driven. Bearings shall be pillow block ball bearing type, having extended grease lines for ease of lubrication. V-belt drives shall include heat, oil, and static resistant belts. Fan section shall include service door for inspection and maintenance of fan and drive.

The filter section shall contain a framework supporting standard disposable type air filters. Filters shall be configured in a "V-bank" arrangement, maximizing media surface and minimizing filtration velocity. Filter sections shall include a full face access door for inspection and maintenance of filters.

The heating sections shall consist of a fully enclosed atmospheric burner for combustion of natural or propane gases; a control system to activate/deactivate the unit, monitor, and regulate the combustion process, and modulate the discharge air temperature. Access to the interior of the heating section shall be through an access door. The burner shall be classified as a commercially available, industrial duty, natural or propane gas type line burner. Burner construction shall consist of a cast iron main body with stainless steel mixing plates attached. Heating section shall include location of burner within a baffle arrangement to support proper combustion. Main burner ignition shall be accomplished with a pilot flame activated by an interrupted ignition device. Combustion shall be monitored by an ultraviolet sensing flame safeguard system. Airflow speed over the burner is factory preset.

The electromechanical control system shall be contained in a NEMA 4/12 cabinet, on the exterior of the fan casing. A discharge high air temperature sensor mounted in housing shall prevent operation under abnormal and hazardous condition. Airflow over the burners shall be proven before pilot ignition. High and low gas pressure switches shall be furnished to prevent operation under marginal supply pressure conditions. A Maxitrol Series 14 or 44 shall modulate the gas flow to the main burner in response to a discharge air temperature sensor. The unit shall have a Honeywell 7800 Series flame monitoring system. A magnetic full voltage fan motor starter shall be included along with a fused disconnect switch.

Units are available, tested, and built to comply with FM/IRI insurance standards.