SECTION 23 52 16
WALL-HUNG GAS-FIRED CONDENSING HOT WATER BOILERS
FOR HYDRONIC HEATING APPLICATIONS
PART 1 - GENERAL
1.1
SECTION INCLUDES
A.
Boiler
1.2
B.
Boiler Controls
RELATED REQUIREMENTS
A.
Section 23 08 00 – HVAC Commissioning Requirements
B.
Section 23 21 14 – Hydronic Specialties
C.
Section 23 09 13 – Instrumentation and Control Devices for HVAC: Installation and wiring of indoor/outdoor controllers
1.3
D.
Section 26 27 17 – Equipment Wiring: Electrical characteristics and wiring connections
REFERENCE STANDARDS
A.
ASME – American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code
Section IV – Rules for Construction of Heating Boilers; The American Society of Mechanical
Engineers
B.
CSA International – Certified and listed by CSA International and harmonized with latest edition of American National Standards Institute (ANSI) Z21.3 for United States and Canada
C.
ASHRAE – Minimum efficiency standards as set forth by the latest edition of (ASHRAE) 90.1.
1.4
SUBMITTALS
A.
Product Data: Provide literature indicating general assembly components, controls, safety controls, wiring diagrams with electric characteristics and connection requirements, and service connections.
B.
Shop Drawings: Indicate assembly, weights, heater configuration, and electric characteristics and connection requirements.
C.
Manufacturer’s Instructions: Indicate rigging, installation, and start-up procedures.
D.
Manufacturer’s Field Reports: Indicate conditions observed after start-up, including control settings.
E.
Operation and Maintenance Data: Include Manufacturer’s descriptive literature, operating instructions, cleaning procedures, replacement parts list, and maintenance repair data.
F.
Warranty: Submit manufacturer warranty and ensure forms have been completed in the Owner’s name and registered with manufacturer.
1.5
REGULATORY REQUIREMENTS
A.
Conform to ASME Section IV for boiler construction. “H” stamped heat exchanger registered with National Board.
B.
CSA certified per ANSI Z21.13.
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C.
Third-party verified maximum NOx production of 20 ppm. Pre-certified and listed with
SCAQMD.
1.6
DELIVERY, STORAGE, AND HANDLING
A.
Protect units before, during, and after installation from to jacket, control panel, or other boiler components by leaving factory packaging in place until immediately prior to final acceptance.
1.7
WARRANTY
A.
Warranty: Manufacturer’s standard form in which Manufacturer agrees to repair or replace heat exchanger and selected (limited) manufactured components that fail in material or workmanship within in specified warranty period.
1.
Condensing hot water boilers for hydronic heating: Lifetime Limited Warranty (verify warranty with manufacturer) from date of substantial completion, if proper water treatment and boiler preventative maintenance are followed.
2.
Required water quality: pH balance between 6.5 and 8 is required. General hardness of not more than 9 grains.
PART 2 - PRODUCTS
2.1
2.2
MANUFACTURERS
A.
Unical/Lattner a division of Lattner Boiler Company.
B.
Or approved equal that conforms to this specification.
MANUFACTURED UNITS
A.
Description: Manufacturer shall provide CSA-listed wall-hung condensing hot water boiler.
Boiler shall be completely packaged, factory assembled, wired, and ready for operation except for piping and electrical connections.
B.
Rated output: Nominal heat output of 223,000 Btus.
C.
Fuel efficiency: Fuel efficiency in full condensing mode of 96%+.
D.
Turndown: Minimum 4.5:1 turndown on a single unit.
E.
Electrical supply: 120/60/1.
F.
Burner components:
1.
2.
3.
4.
Sealed pre-mixed modulating fan.
On-ratio gas valve.
Metal fiber burner.
Flame detection electrode
5.
6.
Ignition electrode.
Overheating thermostat.
7.
A separate air intake connection shall be provided for combustion air.
G.
Control: Integral electronic control device for controlling temperature set point, operating program, overheating protection, multi-zone control, run-time data logging, external (0-10 VDC) control signals.
H.
Heat exchanger:
2

1.
2.
Single-cast heat exchanger shall be constructed of anodized aluminum/magnesium/silicon alloy.
Constructed in accordance with the ASME Section IV and shall be stamped with an “H” stamp.
3.
Heat exchanger be hydrostatically test and inspected by a third-party inspector and registered with The National Board.
Condensate shall drain at bottom of heat exchanger. 4.
I.
Circulating pump: Standard integral circulating pump.
J.
Jacket and installation: Sheet metal jacketing painted with epoxy-polyester powders and internally insulated with reflecting polyethylene (5+ mm thickness).
K.
Nozzles and connections:
1.
2.
3.
4.
Cold water inlet – 1”
Hot water outlet – 1”
Natural gas supply – ¾”
Air intake – 3.15” (80 mm)
Flue outlet – 3.15” (80 mm)
Condensate drain – 0.98” (25 mm)
5.
6.
L.
Trim:
1.
2.
3.
4.
5.
ASME-rated pressure relief valve.
Flue condensate drain.
Bottom/heat exchanger condensate drain.
Flow temperature sensor (hot water supply).
Return temperature sensor.
6.
M.
Venting:
Low water switch.
1.
2.
Venting material – Venting material must meet category IV requirement for positive pressure, condensing system.
Common venting of “cascade” units – Multiple units may be commonly vented.
Comment vent kit is optional. Refer to manual or vent supplier for venting design and instructions.
3.
Maximum total horizontal run not to exceed 98’.
N.
Dimensions:
1.
Overall dimensions shall not exceed: i.
Width: 25” (615 mm) ii.
Depth: 11” (266 mm) iii.
Height: 37” (930 mm) iv.
Weight: 110 lbs.
3

O.
Quality control:
1.
Manufacturer shall perform comprehensive “RUN” test, including filling the boiler with water, connecting gas, connecting vent, connecting electricity, operating the boiler under
“FIELD” conditions, and adjusting the gas valve to achieve optimal air/gas ratio.
PART 3 – EXECUTION
3.1
EXAMINATION
A.
Verify service and code requirements.
3.2
INSTALLATION
A.
Install in strict accord with manufacturer’s instructions.
B.
Provide piping connection and accessories as indicated.
C.
Pipe relief valves to nearest floor drain.
D.
Provide for single point electrical service. Verify electrical requirements with electrical contractor, in particular service loads and disconnecting means. Refer to Section 26 2717.
3.3
START-UP
A.
Check all safety devices.
B.
Check all piping connections.
C.
Adjust temperature controls according to Manufacturer’s instructions.
D.
Verify temperature controls with consulting engineer or onsite project manager.
E.
Tighten all electrical connections including element terminations according to Manufacturer’s instructions.
F.
Verify that at least one operations manual resides with the boiler.
G.
Demonstrate proper operation of equipment to Owner’s designated representative.
3.4
CLOSEOUT ACTIVITIES
A.
Provide Manufacturer’s start-up report to Owner and Manufacturer.
B.
Provide the services of Manufacturer’s field service representative to conduct operations and maintenance training.
3.5
SCHEDULES
A.
Refer to Schedule on Drawings for input/output requirements.
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