GUIDE SPECIFICATION SECTION235533-1
Revised 16 February 2016Fuel-Fired Unit Heaters
SECTION 235533 - FUEL-FIRED UNIT HEATERS
PART 1 GENERAL
RELATED DOCUMENTS
Drawings and general provisions of Contract, including General and Supplementary Conditions and Division1 Specification sections, apply to work of this section.
QUALITY ASSURANCE
UL Compliance: Construct and install oilfired unit heaters in accordance with UL 731, OilFired Unit Heaters.
ANSI Compliance: Construct and install gasfired unit heaters in accordance with ANSI Z83.8, Gas Unit Heaters.
SUBMITTALS
General: Submittals shall demonstrate compliance with technical requirements by reference to each subsection of this specification. Where a submitted item does not comply fully with each and every requirement of the Specifications, the submittal shall clearly indicate such deviations. Identification requirements for non-complying features of items are very specific. See Section 230210 for exact requirements.
Manufacturer's Data: Submit manufacturer's technical product data, including rated capacities of selected model clearly indicated, weights, furnished specialties and accessories, and installation and startup instructions.
Wiring Diagrams: Submit manufacturer's electrical requirements for power supply wiring for fuelfired heaters. Submit manufacturer's laddertype wiring diagrams for interlock and control wiring. Clearly differentiate between portions of wiring that are factoryinstalled and portions to be fieldinstalled.
PART 2 PRODUCTS
GASFIRED, PROPELLER FAN UNIT HEATERS
Provide gasfired propeller unit heaters as indicated, of type and minimum capacity as scheduled, and as specified herein.
Construct casing of galvanized steel, with baked enamel finish. Provide integral inserts for hanger rods.
Provide 4way air diffusion louvers mounted on face of unit.
Construct heat exchanger of welded aluminized steel. Provide draft diverter or collector box and integral power exhauster as required, construct integral to each heat exchanger section. Provide oval or round flue collar.
Construct burner of same material as heat exchanger, and include integral burner crossover. Design burner to be suitable for propane or natural gas.
Construct fan of aluminum, direct drive propeller type, and factorybalance.
Provide the following controls, factorypiped and wired to electrical junction box mounted on unit:
Automatic gas valve
Safety pilot with 100% shutoff
Pressure regulator with leak limiting device
Manual main and adjustable pilot valves
High Limit switch
Certify units are in conformance with AGA applicable regulations.
Provide the following accessories, factorymounted, and wired to electrical junction box:
2stage gas valve providing 2stage control of 100% or approximately 55% of full unit rating
Electric spark ignition
Louver fin diffusers to control horizontal spread of discharge air stream
GASFIRED, CENTRIFUGAL FAN UNIT HEATERS
Provide gasfired centrifugal unit heaters as indicated, of type and minimum capacity as scheduled, and as specified herein.
Construct casing of galvanized steel, with enamel finish. Provide integral inserts for hanger rods.
Provide 2way air diffusion louvers on face of unit.
Provide 2way air distribution louvers on down blow nozzle, attached to face of unit.
Construct heat exchanger of welded aluminized or stainless steel. Provide draft diverter or collector box and integral power exhauster as required, construct integral to each heat exchanger as required, construct integral to each heat exchanger section. Provide oval or round flue collar.
Construct burner of same material as heat exchanger, and include integral burner crossover. Design burner to be suitable for propane or natural gas.
Construct fan of steel, belt drive centrifugal type, and factorybalance.
Provide the following controls, factorypiped and wired to electrical junction box mounted on unit:
Automatic gas valve
Safety pilot with 100% shutoff
Pressure regulator with leak limiting device
Manual main and adjustable pilot valves
High Limit switch
Certify units are in conformance with AGA applicable regulations.
Provide the following accessories, factorymounted, and wired to electrical junction box:
2stage gas valve providing 2stage control of 100% or approximately 55% of full unit rating
Electric spark ignition
OILFIRED PROPELLER FAN UNIT HEATERS
Provide oilfired propeller unit heaters as indicated, of type and minimum capacity as scheduled, and as specified herein.
Construct casing of heavy gage steel, treated for corrosion protection, with enamel finish. Provide integral inserts for hanger rods. Provide horizontal adjustable louvers on discharge for directional air flow pattern.
Construct heat exchanger of welded aluminized steel for primary and secondary surfaces. Provide flame observation port, CO2 sample port, and clean out and service panels.
Construct oil burner for No.2 fuel oil, flame retention, pressure atomizing, gun type with 2stage, 3450 rpm fuel pump. Provide electric spark ignition and automatic safety system with manual reset.
Construct fan of aluminum, direct drive propeller type, and factorybalance.
Provide the following controls, factorypiped, and prewired to electrical junction box mounted on unit:
Combination fan and limit control providing delay of fan until heat exchanger reaches operating temperature
Fan switch for summer operation
Provide units that are Listed.
Provide the following accessories, for field installation:
Oil booster pump, complete with motor and 2stage fuel unit containing pressure regulating valve and strainer
Draft regulator, full size, Listed and Labeled
Oil safety valve
Vertical louvers for mounting in front of horizontal louvers
VENTING
Vent each unit heater in compliance with Section 235113, full size of heater connection.
PART 3 EXECUTION
INSTALLATION OF GASFIRED UNIT HEATERS
Install gasfired unit heaters as indicated, and in accordance with manufacturer's published installation instructions.
Hang units from substrate using threaded rods and building attachments, secure rods to unit hanger attachments in accordance with Section 230529. Adjust hangers so unit is plumb and level.
Extend gas piping to within 5 feet of unit, provide drop with manual gas shutoff valve, 1/8" NPT plugged test connection, tee, and drip pocket. Locate piping drop so as to not interfere with service of unit. Extend gas piping runout, full size of gas train inlet, from tee to gas train connection, provide union with sufficient clearance for unit removal and service.
Adjust air diffusion louvers for proper air flow.
INSTALLATION OF OILFIRED UNIT HEATERS
Install oilfired unit heaters as indicated, and in accordance with manufacturer's published installation instructions.
Hang units from substrate using threaded rods and building attachments, secure rods to unit hanger attachments in accordance with Section 230529. Adjust hangers so unit is plumb and level.
Extend oil piping to within 5 feet of unit. Provide manifold bleed for pressurized system at high point, provide vent at high point and oil return piping for loop system. Locate oil feeder line so as not to interfere with service of unit. Extend oil piping runout, full size of oil burner inlet, with shutoff valve to oil burner. Provide union with sufficient clearance for unit removal and service.
Adjust air diffusion louvers for proper air distribution.
STARTUP
Startup, test, and adjust fuelfired unit heaters in accordance with manufacturer's published startup instructions. Adjust air diffusion louvers for proper air flow. Verify proper line and manifold gas pressure. Check and calibrate controls, adjust burner for maximum efficiency.
OWNER INSTRUCTION AND TRAINING
Provide Owner instruction and training in accordance with Section 230240.