SECTION 15485 DOMESTIC WATER HEATERS
PART 1 - GENERAL
1.1 SUMMARY
A. This Section includes the following for domestic water systems:
1. Commercial, electric water heaters.
2. Accessories.
1.2 SUBMITTALS
A. Product Data: For each type and size of water heater. Include rated capacities; ship- ping, installed, and operating weights; furnished specialties; and accessories.
B. Shop Drawings: Detail water heater assemblies and indicate dimensions, weights, loads, required clearances, method of field assembly, components, and location and size of each field connection.
1. Wiring Diagrams: Power, signal, and control wiring. Differentiate between manufacturer-installed and field-installed wiring.
C. Product Certificates: Signed by manufacturers of water heaters certifying that products furnished comply with requirements.
D. Maintenance Data: For water heaters to include in maintenance manuals specified in Division 1.
E. Warranties: Special warranties specified in this Section.
1.3 QUALITY ASSURANCE
A. Source Limitations: Obtain same type of water heaters through one source from a sin- gle manufacturer.
B. Product Options: Drawings indicate size, profiles, and dimensional requirements of water heaters and are based on specific units indicated. Other manufacturers' products complying with requirements may be considered. Refer to Division 1 Section "Substi- tutions."
C. Electrical Components, Devices, and Accessories: Listed and labeled as defined in NFPA 70, Article 100, by testing agency acceptable to authorities having jurisdiction, and marked for intended use.
D. ASME Compliance: Fabricate and label water heater, hot-water storage tanks to com- ply with ASME Boiler and Pressure Vessel Code: Section VIII, "Pressure Vessels," Division 1.
E. ASHRAE Standards: Comply with performance efficiencies prescribed for the follow- ing:
1. ASHRAE 90.1, "Energy Efficient Design of New Buildings except Low-Rise Residential Buildings," for commercial water heaters.
1.4 WARRANTY
A. General Warranty: Special warranty specified in this Article shall not deprive Owner of other rights Owner may have under other provisions of the Contract Documents and shall be in addition to, and run concurrent with, other warranties made by Contractor under requirements of the Contract Documents.
B. Special Warranty: Written warranty, executed by manufacturer agreeing to repair or replace components of water heaters that fail in materials or workmanship within speci- fied warranty period.
1. Failures include heating elements and storage tanks.
2. Warranty Period: From date of Substantial Completion:
a. Heating Elements: Five years.
b. Storage Tanks: 10 years.
PART 2 - PRODUCTS
2.1 COMMERCIAL, STORAGE, ELECTRIC WATER HEATERS
A. Manufacturers: Subject to compliance with requirements, provide products by one of the following:
1. Commercial, Storage, Electric Water Heaters:
a. Smith: A. O. Smith Water Products Co.
b. Rheem Manufacturing Co.; Ruud Water Heater Div.
2. Water Heater Stand and Drain Pan Units:
a. Safety: W. H. Safety Products, Inc.
B. Description: Comply with UL 1453.
C. Storage Tank Construction: Steel with 150-psig (1035-kPa) working-pressure rating.
1. Tappings: Factory fabricated of materials compatible with tank for piping con- nections, relief valve, pressure gage, thermometer, drain, anode rods, and con- trols as required. Attach tappings to tank shell before testing and labeling.
a. NPS 2 (DN50) and Smaller: Threaded ends according to ASME B1.20.1, pipe threads.
b. NPS 2-1/2 (DN65) and Larger: Flanged ends according to ASME B16.5 for steel and stainless-steel flanges and according to ASME B16.24 for copper and copper-alloy flanges.
2. Interior Finish: Materials and thicknesses complying with NSF 61, barrier mate- rials for potable-water tank linings. Extend finish into and through tank fittings and outlets.
3. Insulation: Comply with ASHRAE 90.1. Surround entire storage tank except connections and controls.
4. Jacket: Steel, with enameled finish.
D. Heating Elements: Electric, screw-in or bolt-on, immersion type arranged in multiples of three.
1. Exception: Water heaters up to 9-kW input may have 2 or 3 elements.
2. Staging: Input not exceeding 18 kW per step.
3. Temperature Control: Adjustable, immersion thermostat.
4. Safety Controls: Automatic, high-temperature-limit and low-water cutoff devic- es or systems.
E. Drain Valve: ASSE 1005, corrosion-resistant metal, factory installed.
F. Anode Rods: Factory installed, magnesium.
G. Dip Tube: Factory installed. Not required if cold-water inlet is near bottom of storage tank.
H. Special Requirement: NSF 5 construction.
2.2 WATER HEATER ACCESSORIES
A. Automatic Valves: ANSI Z21.21, appliance, electrically operated, on-off automatic valve.
B. Water Heater Stand and Drain Pan Units: High-density-polyethylene-plastic, 18-inch- (457-mm-) high, enclosed-base stand complying with IAPMO PS 103 and IAS No. 2. Include integral or separate drain pan with raised edge and NPS 1 (DN25) drain outlet with ASME B1.20.1, pipe thread.
C. Water Heater Mounting Brackets: Water heater manufacturer's factory-fabricated, steel bracket for wall mounting and capable of supporting water heater and water.
D. Drain Pans: Corrosion-resistant metal with raised edge. Include dimensions not less than base of water heater and include drain outlet not less than NPS 3/4 (DN20).
E. Piping-Type Heat Traps: Field-fabricated piping arrangement according to ASHRAE 90.1 or ASHRAE 90.2.
F. Combination Temperature and Pressure Relief Valves: ASME rated and stamped and complying with ASME PTC 25.3. Include relieving capacity at least as great as heat input and include pressure setting less than water heater working-pressure rating. Se- lect relief valve with sensing element that extends into tank.
1. Option: Separate temperature and pressure relief valves are acceptable instead of combination relief valve.
2. Exception: Omit combination temperature and pressure relief valve for tankless water heater, and furnish pressure relief valve for installation in piping.
G. Pressure Relief Valves: ASME rated and stamped and complying with ASME PTC 25.3. Include pressure setting less than heat-exchanger working-pressure rating.
H. Vacuum Relief Valves: Comply with ASME PTC 25.3. Furnish for installation in pip- ing.
1. Exception: Omit if water heater has integral vacuum-relieving device.
I. Shock Absorbers: ASSE 1010 or PDI WH 201, Size A water hammer arrester.
PART 3 - EXECUTION
3.1 WATER HEATER INSTALLATION
A. Install commercial water heaters on concrete bases for floor mounted applications..
1. Exception: Omit concrete bases for water heaters if installation on stand, brack- et, suspended platform, or direct on floor is indicated.
B. Install water heaters, level and plumb, according to layout drawings, original design, and referenced standards. Maintain manufacturer's recommended clearances. Arrange units so controls and devices needing service are accessible.
C. Anchor water heaters to substrate.
D. Install temperature and pressure relief valves in top portion of storage tanks. Use relief valves with sensing elements that extend into tanks. Extend relief valve outlet with wa- ter piping in continuous downward pitch and discharge onto closest floor drain.
E. Install pressure relief valves in water piping for water heaters without storage. Extend relief valve outlet with water piping in continuous downward pitch and discharge onto closest floor drain.
F. Install vacuum relief valves in cold-water-inlet piping.
G. Install water heater drain piping as indirect waste to spill into open drains or over floor drains. Install hose-end drain valves at low points in water piping for water heaters that do not have tank drains. Refer to Division 15 Section "Plumbing Specialties" for drain valves.
H. Install thermometers on water heater inlet and outlet piping. Adjust faces to proper angle for best visibility.
I. Assemble and install inlet and outlet piping manifold kits for multiple water heaters. Fabricate, modify, or arrange manifolds for balanced water flow through each water heater. Include shutoff valve, and thermometer in each water heater inlet and outlet, and throttling valve in each water heater outlet. Refer to Division 15 Section "Plumb- ing Valves" for general-duty valves and Division 15 Section "HVAC Meters and Gag- es" for thermometers.
J. Install piping-type heat traps on inlet and outlet piping of water heater storage tanks without integral or fitting-type heat traps.
K. Fill water heaters with water.
3.2 CONNECTIONS
A. Piping installation requirements are specified in other Division 15 Sections. Drawings indicate general arrangement of piping, fittings, and specialties.
B. Install piping adjacent to machine to allow service and maintenance.
C. Connect hot- and cold-water piping with shutoff valves and unions.
D. Make connections with dielectric fittings where piping is made of dissimilar metal.
E. Electrical Connections: Power wiring and disconnect switches are specified in Divi- sion 16 Sections. Arrange wiring to allow unit service.
F. Ground equipment.
1. Tighten electrical connectors and terminals according to manufacturer's pub- lished torque-tightening values. If manufacturer's torque values are not indicated, use those specified in UL 486A and UL 486B.
3.3 FIELD QUALITY CONTROL
A. Engage a factory-authorized service representative to perform startup service.
B. In addition to manufacturer's written installation and startup checks, perform the fol- lowing:
1. Test and adjust controls and safeties. Replace damaged and malfunctioning con- trols and equipment.
2. Verify that piping system tests are complete.
3. Check for piping connection leaks.
4. Check for clear relief valve inlets, outlets, and drain piping.
5. Test operation of safety controls, relief valves, and devices.
6. Energize electric circuits.
7. Adjust operating controls.
8. Adjust hot-water-outlet temperature settings. Do not set above 140 deg F (60 deg C) unless piping system application requires higher temperature.
END OF SECTION
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