The Metropolitan Water Reclamation District of Greater Chicago
General Specifications
SECTION 23 7312
AIR HANDLING UNIT COILS
PART 1 - GENERAL
1.1
SUMMARY
A.
Section Includes:
1. Hot water coils.
2. Steam coils – Horizontal tube steam distribution.
3. Steam coils – Integral face and bypass.
4. Chilled water coils.
5. Refrigerant coils.
6. Hot water coil installation.
7. Steam coils – Horizontal tube steam distribution installation.
8. Steam coils – Integral face and bypass installation.
9. Chilled water coils installation.
10. Refrigerant coils installation.
B.
Related Documents:
1. Applicable provisions of Division 00 – Procurement and Contracting
Requirements shall govern work of this specification section.
C.
Related Sections:
1. Applicable provisions of Division 01 shall govern Work under this Section.
2. Applicable provisions of the MWRDGC General and Detailed Technical
Specifications utilized for this project.
1.2
REFERENCES
A.
1.3
Air-Conditioning and Refrigeration Institute
1. ARI 410 - Forced Circulation Air-Cooling and Air-Heating Coils.
SUBMITTALS
A.
Section 01 33 00 - Submittal Procedures: Requirements for submittals.
B.
Submit data concerning dimensions, capacities, flow rate, pressure drop, materials of
construction, ratings, weights, and appropriate identification at same time that airhandling equipment, in which coils will be located.
1.4
DESIGN CRITERIA
A.
Select coil sizes, capacities, configuration, and operating characteristics as shown on
Drawings or as scheduled. Coil capacity ratings shall be ARI 410 certified.
2012 EDITION
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AIR HANDLING UNIT COILS
The Metropolitan Water Reclamation District of Greater Chicago
General Specifications
PART 2 - PRODUCTS
2.1
MANUFACTURERS
A.
2.2
Air Handling Unit Coils:
1. Aerofin Corporation.
2. Trane.
3. Carrier Corporation.
4. Controlair, Inc.
5. McQuay International.
6. RAE Corporation.
7. L.J. Wing.
8. York Division Johnson Controls..
9. Substitutions: In accordance with Section 01 2500 – Substitution Procedures.
HOT WATER COILS
A.
Use galvanized steel casing, end supports, top channel, and bottom channel to produce
a rigid frame with allowance for expansion and contraction of finned tube section.
B.
Construct coils of 0.025-inch tube wall seamless copper tubes of 5/8-inch maximum
outside diameter with maximum of eight (8) aluminum fins for every inch suitable for
working pressures to 125 psig and temperatures to 250 degrees F.
C.
Coil fins may be continuous serpentine or plate fin type.
D.
Construct coil headers of cast iron, steel, or seamless copper.
E.
Where cast iron headers are used, expand tubes into headers. Where steel or copper
headers are used, braze tubes to header.
F.
Provide coils with bronze spring turbulators where required to provide capacities
indicated.
2.3
STEAM COILS - HORIZONTAL TUBE STEAM DISTRIBUTION
A.
Use galvanized steel casing, end supports, top channel, and bottom channel to produce
a rigid frame with allowance for expansion and contraction of finned tube section.
B.
Construct coils of 0.035-inch tube wall seamless copper tubes of one (1) inch maximum
outside diameter outer tube, 0.035-inch tube wall steam distributing seamless copper
inner tube, and a maximum of eight (8) aluminum fins per inch, suitable for working
pressures to 125 psig and temperatures to 250 degrees F.
C.
Coil fins may be continuous serpentine or plate fin type.
D.
Construct coil headers of cast iron, steel, or seamless copper. Where cast iron headers
are used, expand tubes into headers. Where steel or copper headers are used, braze
tubes to header.
2012 EDITION
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AIR HANDLING UNIT COILS
The Metropolitan Water Reclamation District of Greater Chicago
General Specifications
2.4
STEAM COILS - INTEGRAL FACE AND BYPASS
A.
Coils shall be vertical type, consisting of a series of finned heating elements and bypass dampers.
B.
Arrange dampers to completely enclose and isolate heating coil when no heating is
required, open to coil face upon loss of control air, and have factory mounted
pneumatic actuators with pilot positioners, and linkages.
C.
Volume of air passing through coil shall not vary more than plus or minus five (5)
percent regardless of position of internal dampers.
D.
Provide mixing baffles to help provide for mixing air at lower velocities due to fan
turndown.
E.
Fabricate finned heating elements of seamless, straight, vertical copper tubes with
aluminum fins spaced not closer than 8 fins per inch.
F.
Individually secure each tube to steam and return headers by a brazed joint. Minimum
tube wall thickness to be 0.035-inch.
G.
Coils to be suitable for working pressures to 200 psig and temperatures to 250 degrees
F.
2.5
CHILLED WATER COILS
A.
Use galvanized steel casing, end supports, top channel, and bottom channel to produce
a rigid frame with allowance for expansion and contraction of finned tube section.
B.
Construct coils of 0.025-inch tube wall seamless copper tubes of 5/8-inch maximum
outside diameter with maximum of eight (8) aluminum fins for every inch suitable for
working pressures to 200 psig.
C.
Coil fins may be continuous serpentine or plate fin type.
D.
Construct coil headers of cast iron, steel, or seamless copper. Where cast iron headers
are used, expand tubes into headers.
E.
Where steel or copper headers are used, braze tubes to header.
F.
Coils shall be drainable type with drain and vent plugs for each header.
2.6
REFRIGERANT COILS
A.
Use galvanized steel casing, end supports, top channel, and bottom channel to produce
a rigid frame with allowance for expansion and contraction of finned tube section.
B.
Construct coils of minimum 1/2-inch outside diameter copper tubes with aluminum
fins. Test at 250 psig, dehydrate, purge with inert gas, and seal prior to shipment.
2012 EDITION
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AIR HANDLING UNIT COILS
The Metropolitan Water Reclamation District of Greater Chicago
General Specifications
C.
Construct suction header of seamless copper tubing. Use a low-pressure drop venturi
type distributor to distribute refrigeration equally to multiple circuits.
D.
Coil fins shall be continuous serpentine or plate fin type.
PART 3 - EXECUTION
3.1
HOT WATER COIL INSTALLATION
A.
Install in central station air handling unit casings or on structural support frames for
field erected units, making allowance for pitching as recommended by manufacturer.
B.
Comb bent or crushed fins after installation. Clean dust and debris from each coil to
ensure its cleanliness.
C.
Install a separate air vent and drain valve for each coil header in such a manner that
vent and drain valves are located outside of air handling unit casing.
D.
Provide offsets in piping to facilitate coil removal.
E.
Unless otherwise specified, pipe coils for counter flow arrangement.
3.2
STEAM COILS - HORIZONTAL TUBE STEAM DISTRIBUTION INSTALLATION
A.
Install in central station air handling unit casings or on structural support frames for
field erected units, making allowance for pitching as recommended by manufacturer.
B.
Comb bent or crushed fins after installation. Clean dust and debris from each coil to
ensure its cleanliness.
C.
Provide offsets in piping to facilitate coil removal.
D.
Trap each coil individually.
condensate head as detailed.
E.
Provide vacuum breakers at coil inlet and outlet.
3.3
Pipe trap from coil outlet with sufficient vertical
STEAM COILS - INTEGRAL FACE AND BYPASS INSTALLATION
A.
Install in air handling units on structural supports, making allowance for required steam
traps. Comb bent or crushed fins after installation.
B.
Clean dust and debris from each coil to ensure cleanliness.
C.
Provide offsets in piping to facilitate coil removal.
D.
Trap each coil individually. Pipe trap from coil outlet with sufficient vertical
condensate head as detailed.
2012 EDITION
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AIR HANDLING UNIT COILS
The Metropolitan Water Reclamation District of Greater Chicago
General Specifications
E.
Provide flexible pipe connection at coil bottom outlet as detailed to allow for piping
movement from thermal expansion.
F.
Provide vacuum breaker check valves at coil inlet and outlet.
3.4
CHILLED WATER COIL INSTALLATION
A.
Install in central station air handling unit casings or on structural support frames for
field erected units, making allowance for pitching as recommended by manufacturer.
B.
Comb bent or crushed fins after installation. Clean dust and debris from each coil to
ensure its cleanliness.
C.
Install a separate air vent and drain valve for each coil header in such a manner that
vent and drain valves are located outside of air handling unit casing.
D.
Provide offsets in piping to facilitate coil removal. Unless otherwise specified, pipe
coils for counter flow arrangement.
E.
Where coils are installed in ductwork or field erected air handling units, provide a 11/2-inch deep 18-gauge welded stainless steel drain pan as an integral part of duct or at
coil support.
F.
Install condensate drain trap with proper depth from each cooling coil condensate drain
to nearest drain location.
3.5
REFRIGERANT COIL INSTALLATION
A.
Install in central station air handling unit casings or on structural support frames for
field erected units, making allowance for pitching as recommended by manufacturer.
B.
Comb bent or crushed fins after installation. Clean dust and debris from each coil to
ensure its cleanliness.
C.
Install refrigerant specialties as detailed and in accordance with manufacturer's
instructions. Provide offsets in piping to facilitate coil removal.
D.
Where coils are installed in ductwork or field erected air handling units, provide a 11/2-inch deep 18-gauge welded stainless steel drain pan as an integral part of duct or at
coil support.
E.
Install condensate drain trap with proper depth from each cooling coil condensate drain
to nearest drain location.
END OF SECTION
2012 EDITION
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AIR HANDLING UNIT COILS