235216 SF - CONDENSING BOILERS.DOC

UNIT TRAININGEQUIPMENT SITE ADD/ALT

Copyright 2009 by The American Institute of Architects (AIA)

Exclusively published and distributed by Architectural Computer Services, Inc. (ARCOM) for the AIA

SECTION 235216 - CONDENSING BOILERS

Verify that Section titles referenced in this Section are correct for this Project's Specifications; Section titles may have changed.

PART 1 - GENERAL

1.1 SUMMARY

A. This Section includes packaged, factory-fabricated and -assembled, gas-fired, fire-tube condensing boilers, trim, and accessories for generating hot water.

1.2 ACTION SUBMITTALS

A. Product Data: Include performance data, operating characteristics, furnished specialties, and accessories.

B. Shop Drawings: For boilers, boiler trim, and accessories. Include plans, elevations, sections, details, and attachments to other work.

Retain subparagraph and associated subparagraphs below if boilers are required to withstand specific design loads and Architect either has delegated design responsibility to Contractor or wants to review structural data as another way to verify equipment's compliance with performance requirements. Professional engineer qualifications are specified in Division 01 Section "Quality Requirements."

Retain subparagraph below if equipment includes wiring.

1. Wiring Diagrams: Power, signal, and control wiring.

1.3 INFORMATIONAL SUBMITTALS

Retain first paragraph below if required by seismic criteria applicable to Project. Coordinate with Division 23 Section "Vibration and Seismic Controls for HVAC Piping and Equipment."

A. Source quality-control test reports.

B. Warranty: Special warranty specified in this Section.

1.4 CLOSEOUT SUBMITTALS

A. Operation and maintenance data.

1.5 QUALITY ASSURANCE

A. Electrical Components, Devices, and Accessories: Listed and labeled as defined in NFPA 70, Article 100, by a testing agency acceptable to authorities having jurisdiction, and marked for intended use.

B. ASME Compliance: Fabricate and label boilers to comply with ASME Boiler and Pressure Vessel Code.

"ASHRAE/IESNA 90.1 Compliance" Paragraph may be required to comply with Project requirements or authorities having jurisdiction. Also, LEED Prerequisite EA 2 requires compliance with ASHRAE/IESNA 90.1.

C. ASHRAE/IESNA 90.1 Compliance: Boilers shall have minimum efficiency according to "Gas and Oil Fired Boilers - Minimum Efficiency Requirements."

Delete first paragraph below if boiler rating exceeds 300,000 Btu/h (87.9 kW).

D. DOE Compliance: Minimum efficiency shall comply with 10 CFR 430, Subpart B, Appendix N, "Uniform Test Method for Measuring the Energy Consumption of Furnaces and Boilers."

E. UL Compliance: Test boilers for compliance with UL 795, "Commercial-Industrial Gas Heating Equipment." Boilers shall be listed and labeled by a testing agency acceptable to authorities having jurisdiction.

1.6 WARRANTY

When warranties are required, verify with Owner's counsel that special warranties stated in this Article are not less than remedies available to Owner under prevailing local laws. Coordinate with Division 01 Section "Product Requirements." See discussion about warranties in "Common Boiler Characteristics" Article in the Evaluations in Division 23 Section "Heating Boilers."

A. Special Warranty: Manufacturer's standard form in which manufacturer agrees to repair or replace components of boilers that fail in materials or workmanship within specified warranty period.

Verify available warranties for units and components and insert number below.

1. Warranty Period for Fire-Tube Condensing Boilers:

a. Leakage and Materials: 10 years from date of Substantial Completion.

b. Heat Exchanger Damaged by Thermal Stress and Corrosion: Nonprorated for five years from date of Substantial Completion.

PART 2 - PRODUCTS

2.1 MANUFACTURERS

See Editing Instruction No. 1 in the Evaluations in Division 23 Section "Heating Boilers" for cautions about naming manufacturers and products. Retain one of three paragraphs and list of manufacturers in this Article. See Division 01 Section "Product Requirements."

A. Available Manufacturers: Subject to compliance with requirements, provide products by one of the following:

Retain one of four lists below.

Retain list below for pulse-combustion condensing boilers.

Retain list below for fire-tube condensing boilers.

1. AERCO International.

Retain list below for water-tube condensing boilers.

2. Laars Heating Systems; a division of Waterpik Technologies, Inc.

3. Lochinvar Corporation.

Retain one of four "Manufactured Units" articles below.

2.2 FIRE-TUBE CONDENSING BOILERS

Retain this article for fire-tube condensing boilers.

A. Description: Factory-fabricated, -assembled, and -tested, fire-tube condensing boiler with heat exchanger sealed pressure tight, built on a steel base; including insulated jacket; flue-gas vent; combustion-air intake connections; water supply, return, and condensate drain connections; and controls. Water heating service only.

B. Heat Exchanger: Nonferrous, corrosion-resistant combustion chamber.

C. Pressure Vessel: Carbon steel with welded heads and tube connections.

D. Burner: Natural gas, forced draft.

E. Blower: Centrifugal fan to operate during each burner firing sequence and to prepurge and postpurge the combustion chamber.

Motor characteristics such as NEMA designation, temperature rating, service factor, enclosure type, and efficiency are specified in Division 23 Section "Common Motor Requirements for HVAC Equipment." If different characteristics are required, add subparagraphs below to suit Project.

1. Motors: Comply with requirements specified in Division 23 Section "Common Motor Requirements for HVAC Equipment."

a. Motor Sizes: Minimum size as indicated. If not indicated, large enough so driven load will not require motor to operate in service factor range above 1.0.

F. Gas Train: Combination gas valve with manual shutoff and pressure regulator.

G. Ignition: Spark ignition with 100 percent main-valve shutoff with electronic flame supervision.

H. Casing:

1. Jacket: Sheet metal, with snap-in or interlocking closures.

2. Control Compartment Enclosures: NEMA 250, Type 1A.

If retaining second option in "Jacket" Subparagraph above, delete first subparagraph below.

3. Finish: Baked-enamel protective finish.

4. Insulation: Minimum 2-inch-thick, mineral-fiber insulation surrounding the heat exchanger.

5. Combustion-Air Connections: Inlet and vent duct collars.

6. Mounting base to secure boiler.

Retain subparagraph below for projects in seismic areas. If retaining, also retain "Manufacturer Seismic Qualification Certification" Paragraph in Part 1 "Informational Submittals" Article.

a. Seismic Fabrication Requirements: Fabricate mounting base and attachment to boiler pressure vessel, accessories, and components with reinforcement strong enough to withstand seismic forces defined in Division 23 Section "Vibration and Seismic Controls for HVAC Piping and Equipment" when mounting base is anchored to building structure.

If Project has more than one type or configuration of boiler, delete paragraph and subparagraphs below and schedule boilers on Drawings.

I. Characteristics and Capacities:

1. See drawings for requirements.

2.3 TRIM

In paragraph below, retain first option if boiler operating pressure exceeds 160 psig (1100 kPa) or boiler temperature exceeds 250 deg F (121 deg C).

A. Include devices sized to comply with ANSI B31.9, "Building Services Piping."

Retain option in first paragraph below if using modulating or low-high-low firing sequence.

B. Aquastat Controllers: Operating, firing rate, and high limit.

C. Safety Relief Valve: ASME rated.

D. Pressure and Temperature Gage: Minimum 3-1/2-inch-diameter, combination water-pressure and -temperature gage. Gages shall have operating-pressure and -temperature ranges so normal operating range is about 50 percent of full range.

E. Boiler Air Vent: Automatic.

F. Drain Valve: Minimum NPS 3/4 hose-end gate valve.

Retain paragraph below if pump is a component of boiler. Coordinate with Division 23 Section "Hydronic Pumps."

G. Circulation Pump: Non-overloading, in-line pump with split-capacitor motor having thermal-overload protection and lubricated bearings; designed to operate at specified boiler pressures and temperatures.

2.4 CONTROLS

Retain paragraph below if controls are specified in Division 23 Section "Instrumentation and Control for HVAC."

A. Refer to Division 23 Section "Instrumentation and Control for HVAC."

Delete paragraph above and retain first two paragraphs and associated subparagraphs below if controls are components of boilers. Coordinate with Division 23 Section "Instrumentation and Control for HVAC."

B. Boiler operating controls shall include the following devices and features:

1. Control transformer.

2. Set-Point Adjust: Set points shall be adjustable.

Retain one of two subparagraphs below for operating control sequences.

3. Sequence of Operation: Electric, factory-fabricated and field-installed panel to control burner firing rate to reset supply-water temperature inversely with outside-air temperature. At 0 deg F outside-air temperature, set supply-water temperature at 200 deg F; at 60 deg F outside-air temperature, set supply-water temperature at 140 deg F.

Retain subparagraph below with either "Sequence of Operation" Subparagraph above.

C. Burner Operating Controls: To maintain safe operating conditions, burner safety controls limit burner operation.

1. High Cutoff: Manual reset stops burner if operating conditions rise above maximum boiler design temperature.

2. Low-Water Cutoff Switch: Electronic probe shall prevent burner operation on low water. Cutoff switch shall be manual-reset type.

3. Blocked Inlet Safety Switch: Manual-reset pressure switch field mounted on boiler combustion-air inlet.

4. Audible Alarm: Factory mounted on control panel with silence switch; shall sound alarm for above conditions.

Retain paragraph and subparagraphs below if boiler controls interface with building automation system.

D. Building Automation System Interface: Factory install hardware and software to enable building automation system to monitor, control, and display boiler status and alarms.

Retain subparagraph and associated subparagraphs below if interface with building automation system is through hardwired points and minimal interface is required. If extensive interface is required, delete below and retain second subparagraph below.

1. Hardwired Points:

a. Monitoring: On/off status, low water level alarm.

b. Control: On/off operation, hot water supply temperature set-point adjustment.

Retain subparagraph below if extensive interface with building automation system is required and is beyond that than can be provided by hardwired points. Requirement may exclude some manufacturers listed.

2. A communication interface with building automation system shall enable building automation system operator to remotely control and monitor the boiler from an operator workstation. Control features available, and monitoring points displayed, locally at boiler control panel shall be available through building automation system.

2.5 ELECTRICAL POWER

Retain one of two paragraphs and associated subparagraphs in this Article. Retain first if single-point field power connection is not applicable; retain second if single-point field power connection is applicable.

A. Controllers, Electrical Devices, and Wiring: Electrical devices and connections are specified in Division 26 Sections.

B. Single-Point Field Power Connection: Factory-installed and -wired switches, motor controllers, transformers, and other electrical devices necessary shall provide a single-point field power connection to boiler.

1. House in NEMA 250, Type 1 enclosure.

2. Wiring shall be numbered and color-coded to match wiring diagram.

3. Install factory wiring outside of an enclosure in a metal raceway.

4. Field power interface shall be to fused disconnect switch.

5. Provide branch power circuit to each motor and to controls with a disconnect switch or circuit breaker.

6. Provide each motor with overcurrent protection.

2.6 VENTING KITS

Some boiler manufacturers offer venting kits that can be included with boiler. Retain this Article if venting kit is included with boiler; otherwise, specify kit in Division 23 Section "Breechings, Chimneys, and Stacks."

A. See manufacturer’s requirements for venting materials.

B. Provide concentric venting where permitted.

2.7 SOURCE QUALITY CONTROL

A. Burner and Hydrostatic Test: Factory adjust burner to eliminate excess oxygen, carbon dioxide, oxides of nitrogen emissions, and carbon monoxide in flue gas and to achieve combustion efficiency; perform hydrostatic test.

B. Test and inspect factory-assembled boilers, before shipping, according to ASME Boiler and Pressure Vessel Code.

PART 3 - EXECUTION

3.1 BOILER INSTALLATION

Retain one of three "Equipment Mounting" paragraphs below. Coordinate with Drawings and Sections specifying vibration and seismic controls.

Retain first "Equipment Mounting" Paragraph for equipment supported on cast-in-place concrete equipment bases without vibration isolation devices.

A. Equipment Mounting: Install boiler on existing concrete equipment base.

Retain first "Equipment Mounting" Paragraph below for equipment supported on cast-in-place concrete equipment bases with vibration isolation devices.

Retain or insert amount of required deflection in "Minimum Deflection" Subparagraph below.

Retain "Equipment Mounting" Paragraph below for equipment installed on vibration isolation devices without cast-in-place concrete equipment bases.

B. Install gas-fired boilers according to NFPA 54.

C. Assemble and install boiler trim.

D. Install electrical devices furnished with boiler but not specified to be factory mounted.

E. Install control wiring to field-mounted electrical devices.

3.2 CONNECTIONS

Coordinate piping installations and specialty arrangements with schematics on Drawings and with requirements specified in piping systems. If Drawings are explicit enough, these requirements may be reduced or omitted.

A. Piping installation requirements are specified in other Division 23 Sections. Drawings indicate general arrangement of piping, fittings, and specialties.

B. Install piping adjacent to boiler to allow service and maintenance.

C. Install piping from equipment drain connection to nearest floor drain. Piping shall be at least full size of connection. Provide an isolation valve if required.

D. Connect piping to boilers, except safety relief valve connections, with flexible connectors of materials suitable for service. Flexible connectors and their installation are specified in Division 23 Section "Hydronic Piping."

E. Connect gas piping to boiler gas-train inlet with union. Piping shall be at least full size of gas train connection. Provide a reducer if required.

F. Connect hot-water piping to supply- and return-boiler tappings with shutoff valve and union or flange at each connection.

G. Install piping from safety relief valves to nearest floor drain.

H. Boiler Venting:

1. Install flue venting kit and combustion-air intake.

Delete option in subparagraph below if vent kit is specified in this Section.

2. Connect full size to boiler connections.

I. Ground equipment according to Division 26 Section "Grounding and Bonding for Electrical Systems."

J. Connect wiring according to Division 26 Section "Low-Voltage Electrical Power Conductors and Cables."

3.3 FIELD QUALITY CONTROL

A. Perform tests and inspections and prepare test reports.

Retain subparagraph below to require a factory-authorized service representative to assist Contractor with inspections, tests, and adjustments.

1. Manufacturer's Field Service: Engage a factory-authorized service representative to inspect components, assemblies, and equipment installations, including connections, and to assist in testing.

B. Tests and Inspections:

1. Perform installation and startup checks according to manufacturer's written instructions.

2. Leak Test: Hydrostatic test. Repair leaks and retest until no leaks exist.

3. Operational Test: Start units to confirm proper motor rotation and unit operation. Adjust air-fuel ratio and combustion.

4. Test and adjust controls and safeties. Replace damaged and malfunctioning controls and equipment.

a. Check and adjust initial operating set points and high- and low-limit safety set points of fuel supply, water level, and water temperature.

b. Set field-adjustable switches and circuit-breaker trip ranges as indicated.

C. Remove and replace malfunctioning units and retest as specified above.

D. Occupancy Adjustments: When requested within 12 months of date of Substantial Completion, provide on-site assistance in adjusting system to suit actual occupied conditions. Provide up to two visits to Project during other than normal occupancy hours for this purpose.

3.4 DEMONSTRATION

A. Engage a factory-authorized service representative to train Owner's maintenance personnel to adjust, operate, and maintain boilers. Refer to Division 01 Section "Demonstration and Training."

END OF SECTION 235216

Project No: 390265

CONDENSING BOILERS

235216 - 5