M.C. Blanchard Judicial Building Dell Consulting LLC Dell Project No. 26-022 Boiler Replacement Project

HEATING WATER BOILERS 235200 - 1 of 6

SECTION 235200 – HEATING WATER BOILERS

PART 1 - GENERAL

1.1 Related Documents:

A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 1 Specification sections, apply to this section.

B. Division 23 Common Work Results for HVAC sections apply to work of this section.

C. Extent of boiler work is indicated by drawings and schedules, and requirements of this section.

D. Refer to other Division 23 sections for piping, hydronic specialties, pumps, and temperature controls which are required external to boilers (not work of this section).

E. Refer to other Division 23 sections for testing, adjusting, and balancing of boilers (not work of this section).

F. Refer to Division 26 sections for power supply wiring from power source to power connection on boilers. Include starters, disconnects, wiring, raceways, and required electrical devices, except where specified as furnished, or factory-installed, by manufacturer.

1.2 Electrical Work: Provide the following as work of this section, in accordance with requirements of Division 26:

A. Furnish to Electrical Installer burner emergency shutoff switches.

B. Provide factory-mounted and wired controls and electrical devices as specified in this section.

C. Provide control wiring between boiler control panel and thermostats, aquastats, and any other control device.

1.3 Codes and Standards:

A. AGA Compliance: Boilers shall be design certified by the American Gas Association.

B. NFPA Compliance: Install gas-fired boilers in accordance with NFPA Code 54 "National Fuel Gas Code".

C. Boilers shall bear the ASME stamp and be approved by the National Board for 160 psig working pressure.

D. UL and NEMA Compliance: Provide boiler ancillary electrical components which have

HEATING WATER BOILERS 235200 - 2 of 6 been listed and labeled by UL, and comply with NEMA standards.

1.4 Approval Submittals:

A. Product Data: Submit manufacturer's technical product data, including rated capacities of selected model clearly indicated, weights (shipping, installed, and operating), furnished specialties and accessories; and installation and startup instructions.

B. Assembly Drawings: Submit manufacturer's assembly-type drawings indicating dimensions, weight loadings, required clearances, and methods of assembly of components.

1.5 Test Report and Verification Submittals:

A. Startup Report: Submit startup report by factory-trained representative.

B. Training: Submit letter verifying that Owner training has been received by factory representative.

1.6 O&M Data Submittals:

A. Wiring Diagrams: Submit manufacturer's electrical requirements for power supply wiring to boilers. Submit manufacturer's ladder-type wiring diagrams for interlock and control wiring required for final installation of boilers and controls. Clearly differentiate between portions of wiring that are factory-installed and portions to be field-installed.

B. Maintenance Data: Submit a copy of approval submittal. Submit maintenance data and parts list for boilers, controls, and accessories; include "troubleshooting" maintenance guide. Include data in O&M manual.

PART 2 - PRODUCTS

2.1 Acceptable Manufacturers: Subject to compliance with requirements, provide boilers by:

Aerco - basis of design, and comparable to equipment previously installed to replace existing equipment.

2.2 Fire-Tube Condensing Boilers:

A. General: Provide as indicated, factory-assembled and tested, natural gas-fired, fully condensing, fire-tube design hot water boilers of capacity as scheduled. Provide design certified by AGA and constructed in accordance with requirements of the ASME Boiler and Pressure Vessel Code.

B. Heat Exchanger: The heat exchanger shall bear the ASME “H” stamp for 160 psi working pressure and shall be National Board listed. The heat exchanger shall be constructed of a fully welded 316L or 439 stainless steel and of fire-tube design. Heat exchanger

HEATING WATER BOILERS 235200 - 3 of 6 shall be designed for a single-pass water flow to limit the water-side pressure drop.

There shall be no banding material, bolts, gaskets, or “O” rings in the heat exchanger design.

C. Condensate Collection Basin: Fully welded 316L stainless steel.

D. Intake Filter and Dirty Filter Switch: Boiler shall include an intake air filter with a factory-installed air pressure switch. The pressure switch shall alert the end user on the boiler display panel that the intake is dirty and filter needs replacement.

E. Pressure Vessel: The pressure vessel shall be in accordance with ASME Section IV pressure vessel code. The pressure vessel shall be designed for a single-pass flow to limit the water-side pressure drop.

F. Burner: Natural gas, forced draft single burner premix design. Operation of the burner shall not exceed that of 5.7% oxygen level or 40% excess air. The burner shall be high temperature stainless steel with a woven Fecralloy outer covering to provide modulating firing rates. The burner shall be capable of the stated gas train turndown without loss of combustion efficiency. The burner shall be removable from the boiler without removing the gas/air manifold.

G. Blower: Boiler shall be equipped with a fully modulating blower system to precisely control the fuel/air mixture to provide modulating boiler firing rates for maximum efficiency. The burner firing sequence of operation shall include pre-purge, firing, modulating, and post-purge operation.

1. Motors shall comply with requirements specified in Division 23 section “Motors”.

H. Gas Train: The boiler shall be supplied with two gas valves designed with negative pressure regulation and shall be capable of the minimum turndown specified in the equipment schedule.

I. Ignition: Spark ignition with 100% main-valve shutoff with electronic flame supervision.

Boiler using a pilot for ignition and/or UV scanners for flame supervision shall be deemed unacceptable.

J. Casing:

1. Jacket: Heavy gauge primed and painted steel jacket with snap-in closures.

Jacket panels shall be fully removable; the front door and side panels shall not require tools for removal. The jacket shall be mounted on a steel base with minimum 1/4” thickness.

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

3. Insulation: Minimum 1/2” thickness, mineral fiber insulation surrounding the heat exchanger.

4. Combustion Air Connections: Inlet and vent duct collars.

5. Clearances: Boilers shall feature zero clearance to combustibles. Boilers shall have the ability to be placed side-by-side in multiples with no clearance in between if necessary. Coordinate with local codes.

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K. Gas Vents:

1. Single Wall Construction: Provide UL-1738 single wall, factory-built vent system designed for use with Category II or IV condensing gas-fired appliances. The vent system shall be constructed from flame-resistant polypropylene and be continuous from the equipment flue outlet to the vent termination located outside.

All vent system components (vent supports, roof or wall penetrations, terminations, equipment connectors, drain fittings) required to install the vent system shall be UL listed and provide by the manufacturer. Vent layout shall be designed and installed in compliance with the manufacturer’s installation instructions. Acceptable Manufacturer: Subject to compliance with requirements, provide single wall vent system by Centrotherm, IPEX, or approved equal.

2. Double Wall Construction: Provide UL-1738 double wall gas vent system for Category IV gas-fired appliances and in accordance with boiler Installation and Operation Manual similar to Heatfab Saf-T Vent. The system shall include pipe, top, flashing cone, storm collar, joist shield, support plates, firestops, and fittings as required by the manufacturer for a complete installation. Acceptable Producers: Heatfab, Jeremias, Metal-Fab, Selkirk, or approved equal.

L. Accessories: In addition to above, provide the following accessories:

1. Safety Relief Valve: Fully enclosed steel spring with adjustable pressure range and positive shutoff; factory set and sealed at 50 psi.

2. Drain Valves: Minimum NPS 3/4” or nozzle size with hose-end connection.

3. Condensate Trap: Factory-supplied condensate trap with condensate trip sensor.

M. Controls: Boiler controls shall feature the following standard features:

1. LCD screen display indicating status, modulation percentage, setpoints, and sensor data at a minimum on the home screen.

2. Password Security: Boiler shall have a different password security code for the

User and the Installer to access adjustable parameters.

3. Outdoor Air Reset: Boiler shall calculate the setpoint using a field-installed, factory-supplied outdoor sensor and an adjustable reset curve.

4. Isolation Valve Control: Boiler shall have the ability to control a 2-way motorized control valve. Boiler shall also be able to force a fixed number of valves to always be energized regardless of the number of boilers that are firing.

5. BAS Integration with 0-10V DC input: Option to enable and control setpoint temperature or control firing rate by sending the boiler a 0-10V input signal.

6. Boiler shall have a built-in cascade controller to sequence and rotate lead boiler to ensure equal runtime while maintain modulation of multiple boilers without utilization of an external controller.

7. Burner Operating Controls: To maintain safe operating conditions, provide the following burner safety controls.

a. High Temperature Limit

b. Low-Water Cutoff Switch

c. Blocked Inlet Safety Switch

d. High and Low Gas Pressure Switches

e. Blocked Drain Switch

f. Low Air Pressure Switch

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g. Audible Alarm

8. Building Automation System Interface: Factory-installed BACnet MSTP gateway interface to enable building automation system to monitor, control, and display boiler status and alarms.

PART 3 - EXECUTION

3.1 Examine areas and conditions under which boilers are to be installed, and substrate which will support boilers. Do not proceed with work until unsatisfactory conditions have been corrected in manner acceptable to Installer.

3.2 General: Install boilers in accordance with manufacturer's installation instructions, in accordance with State and local code requirements, and in accordance with requirements of local Utility Company. Install units plumb and level. Maintain manufacturer's recommended clearances around and over boilers.

3.3 Registration and Acceptance: Contractor shall register boiler installation with the State Boiler Inspector and schedule all required inspections.

3.4 Support: Install boilers on 6" thick reinforced concrete housekeeping pad that is 6" larger on each side than the base of the unit. Provide chamfered edges.

3.5 Electrical Work: Install electrical devices furnished by manufacturer but not specified to be factory-mounted. Furnish copy of manufacturer's wiring diagram submittal to Electrical Installer. Verify that electrical work installation is in accordance with manufacturer's submittal and installation requirements of Division 26 sections. Do not proceed with equipment start-up until electrical work is acceptable to equipment Installer.

3.6 Gas Piping: Refer to Division 23 section “Gas System”. Connect gas piping to boiler, full size of boiler gas train inlet. Provide union with sufficient clearance for burner removal and service. Coordinate selection of gas regulator and install per manufacturer’s requirements.

3.7 Hot Water Piping: Refer to Division 23 section “Hydronic Piping”. Connect supply and return piping to boiler as indicated, with shutoff valve and union or flange at each connection. Eliminate strain on boiler connections.

3.8 Flush and clean boilers upon completion of installation in accordance with manufacturer's startup instructions. Remove all foreign materials from the exterior of the boiler and touch up damaged factory finish.

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3.9 Hydrostatically test assembled boiler and piping in accordance with applicable sections of ASME Boiler and Pressure Vessel Code. Test to boiler pressure limits, not piping system pressure limits.

3.10 Gas Vent Installation:

A. Install gas vents for gas-fired appliances in accordance with NFPA 54 and the manufacturer's instructions. Provide all flashing and related materials.

B. Slope horizontal gas vent connectors upward at least 1/4” per foot.

3.11 Startup boilers, in accordance with manufacturer's startup instructions, by factory-trained and registered service technician. Test controls and demonstrate compliance with requirements. Adjust burner for maximum burning efficiency. Replace damaged or malfunctioning controls and equipment.

3.12 Owner's Instructions: Provide services of manufacturer's technical representative for one 4-hour day to instruct Owner's personnel in operation and maintenance of boilers.

Schedule training with Owner. Provide at least 7-day notice to Contractor and Engineer of training date.

3.13 Report: Submit signed report that installation is in accordance with factory recommendations and all adjustments and training have been accomplished.

END OF SECTION