23 82 16 - Heating and Cooling Coils

7/29/2019 23 82 16 - Heating and Cooling Coils

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SECTION 23 82 16 - HEATING AND COOLING COILS

PART I - GENERAL

1.1 SECTION INCLUDES

A. Provide materials, devices; labor and supervision necessary to install heat transfer coilsas required by the Drawings and this Section.

1.2 DEFINITIONS

A. AHU: Air Handling Unit (for purposes of coordination with Section 23 73 23 CustomAHU)

B. Booster Coil(s): Duct mounted heating coils located near the end of branch runs andusually associated with Air terminal Units. These coils use a water-glycol mixture orsteam.

C. Coil: Any air to fluid heat transfer surface using copper or cupro-nickel tubing forserpentined fluid circuits and integrally spaced aluminum or copper plate fin surface withwhich the mechanically bonded tubed circuits perpendicularly pass through.

D. Component: Any such item installed on or inside of a heat transfer coil, i.e. cooling orheating coil.

E. Connection Hand: Connection hand orientation shall be configured as The air is hittingthe back of your head in the same direction as the air f low through the unit.

F. Face Velocity: Air handling systems shall not exceed the cross sectional net free areavelocity in fpm as defined in each respective section.

G. Factory Fabricated: Any such component described, as being factory fabricated, shall befabricated by the same Manufacturer having been in the same fabrication business atleast 5 years.

H. Flange \ Mounting: Framing designed for use in Central Station type Air Handlers or foruse with bolt up to duct flanging.

I. FSAD-DS: Full Size Access Door Drive Side

J. Net Free Area: The area perpendicular to the direction of airflow that is exclusive ofobstructions.

K. Tubes Pitched in Coil Casing: Typical for (near horizontal) Steam coil, Specialapplications may also require the cooling coil (stainless steel) casing be constructed so asto orient the rows of copper tubes (and aluminum plate fins) such that they will bephysically pitched downward back to the same-end supply and return headers due to thehorizontal installation of the air handler or built up coil bank.

1.3 DESCRIPTION

A. General Size Ranges: The intent of this Section is to optimize coils into three groups ofsizes by application and general component market availability. [Note to AE: Systems

using airside economizers are needed starting around 3,000 CFM; variable air volumeunits \ systems start around 5,000 CFM and heat recovery systems start around 10,000CFM.] This Section therefore generally assigns units into three groups as follows:

1. A small coil shall be defined as the lower of either the CFM, ranging up to 3000 CFM,or 6 sq. ft. of coil face area, whichever meets the application criteria first.

2. A midsize coil shall be defined as the lower of either the CFM, ranging from 3000CFM up to 20,000 CFM, or 6 sq. ft. to 40 sq. ft. of coil face area, whichever meets theapplication criteria first.

U OF I FACILITIES STANDARDS 23 82 16- 1 HEATING AND COOLING COILSLAST UPDATED JULY 1, 2010


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3. A large coil shall be defined as anything beyond 20,000 CFM or beyond 40 sq. ft.

1.4 SUBMITTALS

A. Schedule:

1. Each Coil system schedule shall include, but not be limited to, the following:

a. Name of Contractor/Manufacturer fabricating each coil system.

b. Material and gage.

c. Certified test results.

d. Support methods including spacing, upper attachments, and lower attachments.

e. Sealant and gasket.

f. Shall include accurately dimensioned drawings with plan, elevation and end viewsof the unit being submitted for approval.

g. Provide any cut views so as to additionally illustrate hidden components notnormally visible from the required views above.

B. Product Data and Material Safety Data Sheets (MSDS):

1. Submit Manufacturers technical product data, installation instructions and MSDS foreach: coil and directly related component, all sealant and gasketing materials, productsand accessories.

C. Submit Shop Drawings:

1. Submit shop drawings of all Coils for entire facility for approval prior to production.Drawings shall be to scale showing structural clearances. Drawings shall include plan,elevation and end views showing all components, with dimensions and connections.Do not release units for production prior to approval of shop drawings by the AE andOwner.

1.5 DELIVERY, STORAGE AND HANDLING

A. Provide All Necessary Means: for delivery, storage and handling of all related materialsand components for the coil system(s) such that they be kept clean and void of allmiscellaneous construction materials including but not limited to dust, dirt, fluids, andscrap materials.

PART 2 - PRODUCTS

2.1 COMPONENTS

A. Coil section(s):

1. Small units will only be required to provide their standard and standard options inorder to comply with the following criteria.

2. Coil Section(s) shall include an IAQ style stainless steel inner drain pan with drain andcapped and threaded drainpipe, minimum 1.5-inch inside diameter, which extends outthrough the base frame. Refer to paragraph on drain pans for more complete criteria.

3. Galvanized steel and galvanized fasteners are acceptable for the preheat coil section,preheat coil casing, reheat coil section and reheat coil casing.

4. Use an IAQ style intermediate welded stainless steel drain pan between stackedcooling coils when necessary due to single coil size limitation or when specificallyrequired. Drain pans shall run continuously under all coil return bends and headers toprovide a continuous condensate capture area. Individual coils (i.e. continuous platefins) shall not exceed 48-inch face or fin height. This criterion is not expected to be anissue for small units.

5. All drain, header and vent connections shall be extended through one side of the unithousing. Connection hand shall be on the same side as the Supply Fan motor unless



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specifically designated on the Drawings and Schedule. Contact the AE if anydiscrepancies are found.

6. All coil mountings and fasteners shall use stainless steel components unless used withpreheat or reheat coils as defined above in this Section.

7. Removal method of coils shall be either tilt-out or slide-out. Coils shall be installedusing removable fasteners of similar material as their respective coil mounts.

8. Sufficient man-sized access space shall be provided between, upstream anddownstream of each coil. Full sized hinged and latched access doors shall be provided

for access to these areas.B. Preheat \ Heat Recovery Section and Coil(s):

1. Meet or exceed related sections of ASHRAE 90.1.

2. Unless a pre-approved Design Phase Variance has been authorized in writing from theOwner, the following shall apply:

3. Unless otherwise stated in this Section, see also Section 23 73 23 Custom AirHandling Units and Project Drawings for additional criteria.

4. Preheat and \ or heat recovery shall be used when outdoor or return air or the resultingmixed air temperature entering the air handling unit can fall below 55 degrees F db.

a. Heat recovery coils or total heat recovery wheel devices (molecular sieve 3-angstrom design for Labs or clean airstreams; 3 or 4 angstrom may be used forgeneral Office non-lab applications) shall be used in applications requiring 5,000cfm or more of once through fresh air. However, the intention of thisparagraph(for units below 5,000 CFM) is not to avoid heat recovery for applications in which2 or more, smaller units would otherwise avoid using heat recovery. Therefore,the application shall dictate the necessity of employing heat recovery, not the sizeand quantity of air handling units.

5. Heat recovery coils (or other recovery means) shall be used in applications requiringthe more stringent of: a) 5,000 cfm or more of once through fresh air, b) current

ASHRAE 90.1 and amendments, c) LEED registered Version Requirements.

6. Air shall be filtered on the upstream side of all heat recovery coils using a minimum 4inch depth MERV 8 or appropriately higher level of filtration efficiencies as scheduledor specified.

7. Duct bypass arrangements and appropriate level of leak-tight dampering shall beconfigured around heat recovery sections allowing replacement \ cleaning maintenancewithout shutting down the system.

8. Though not mandated, it is encouraged to size the main preheating and main coolingcoil capacities as if all or part of the heat recovery system was unavailable.

9. All Cooling and all Heating Coils shall be rated in accordance with ARI standard 410.

10.The parallel plate fins shall be of either minimum thickness 0.010 inch for aluminum ora minimum thickness 0.008 inch for copper.

11.Plate style fin surface may be either of low continuous corrugation (10 FPI max) or flat(12 FPI max). Fin edging shall be rippled or straight. All without lancing or otherserrated enhancements.

a. Air velocity through the full face coil area shall not exceed 500 fpm for 6 or 8 fpi(fins per inch), 475 fpm for 10 fpi, 450 fpm for 12 fpi.

b. Air pressure drop for the coil(s) shall not exceed that referenced in the Scheduleunder design conditions unless pre-approved in writing from Owner.

12.In applications where exposure to freezing temperature inlet conditions exists, preheatglycol based coils may be used and are preferred in lieu of Integral Face and Bypass,External or Internal - Face and Bypass arrangements.



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13.Capacity control of a coil using 1/3, 2/3 is preferred when a single valve potentiallycould have control range limitations.

14.Preheat Coils using water-glycol:

a. Unless otherwise specified, preheat coils shall be based on the following:

1) Water-glycol solution shall be at least 30% glycol by weight.

2) Unless otherwise scheduled and engineered, entering water-glycoltemperature shall be 180 degrees F. The leaving water temperature shall be160 Degree F.

3) Water \ glycol velocity shall not exceed 5 feet per second nor be less than 2.4feet per second under design conditions.

b. Water pressure drop shall be measured at the leaving and entering connectionswhether a single or stacked coil arrangement is used and shall not exceed anequivalent head of 30 ft water column unless specifically stated in the schedule.

15.Preheat Coils using steam:

a. Unless otherwise specified, Pre-Heat or Blast coils using steam shall be basedon the following:

1) A net steam pressure of 5 psig.

2) Automatic control valves for the same net design shall be sized not to exceed

2 psig. pressure drop through the valve at maximum steam consumption.

3) Supply connections and gate valves for blast coils shall be not less than onepipe size larger than their respective automatic valves.

b. Special care shall be taken in sizing all steam coils where modulating control isused so as to obtain even distribution of steam under light heating loads and toprevent stratification of air temperatures. Modulating control shall only beconsidered for coils / applications heating air during above freezing inlettemperatures.

c. All modulating steam coils shall be provided with vacuum breaker and trapdischarge legs with sufficient vertical drop to clear the coil of condensate liquidunder all operating conditions.

d. Vertical tube orientation is preferred for this type of equipment.1) Vertical tube orientation shall have top feeding single pass arrangement.

e. Non-vertical steam pre-heat coils shall use Tube in Tube design utilizing:

1) Coils shall have tubes pitched in casing.

2) Coils shall use 1.0-inch nominal OD outer tube design with 0.049-inchminimum wall thickness for the outer tube.

3) All rows \ coils shall incorporate inner steam distributing tubes using nominal5/8 inch OD copper tubing with 0.035 inch minimum wall thickness.

4) Tubes shall be pitched in casing i.e.) near horizontal and typically havesame end connections for supply and return (condensate) unless the tubefinned length exceeds the manufacturers recommendations or the coil

exceeds 10 feet (for 1.0-inch OD) in which case pre-engineered andscheduled single pass may be provided. Or

a) 10 psig net to coil applications with finned tube length less than 8 feet shall use same end connections, All rows \ coils may incorporate 5/8-inchnominal OD copper tubing with 0.035-inch minimum wall thickness for theouter tube. Inner steam distributing tubes shall then use nominal 3/8-inchOD copper tubing with 0.025-inch minimum wall thickness.



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b) 5 psig net to coil applications with finned tube length less than 8 feet shalluse single pass opposite end connections when pre-engineered andscheduled by the AE. All rows \ coils may incorporate 5/8-inch nominalOD copper tubing with 0.035-inch minimum wall thickness for the outertube. Inner steam distributing tubes shall then use nominal 3/8-inch ODcopper tubing with 0.025-inch minimum wall thickness, single pass design.

5) The parallel plate fins shall be of either minimum thickness 0.010 inch foraluminum or a minimum thickness 0.008 inch for copper.

6) Plate style fin surface may be either of low continuous corrugation (10 FPI

max) or flat (12 FPI max). Fin edging shall be rippled or straight. All withoutlancing or other serrated enhancements.

a) Air velocity through the coil face area shall not exceed 500 fpm for 6 or 8fpi (fins per inch), 475 fpm for 10 fpi, 450 fpm for 12 fpi.

b) Air pressure drop for the cooling coil(s) shall not exceed that referenced inthe Schedule under design conditions unless pre-approved in writing fromOwner.

C. Integral Face and Bypass Section:

1. See related sectionsfor additional criteria.

2. Full-face hot water-glycol preheat coils with modulating control are basis of Design.

a. Integral Face and Bypass Coils IFB may be used in lieu of Full Faced water-Glycol Preheat coils when pre-engineered by the AE and in accordance with:

3. The nature of IFBs air velocities are much faster and require at least (3) feet, and thusdo not allow for adequate mixing upstream of the cooling coil. Therefore, use of IFB sshall also require downstream air blenders integrated into the design or alternative Mfroffering.

a. Alternatively, the Manufacturer proposing IFBs shall provide mixing guaranteeproviding field validation including but not limited to Thermal performancephotography and cross section temperature gradient matrix upstream of thecooling coil.

4. IFB coil casings, housing and dampers shall typically be of the same materials andconstruction as the unit housing unless specified otherwise in the Schedule.

5. Steam Coils (Integral Face and By-Pass)

a. Steam heating coils shall consist of built-in series of finned heating elements andbypasses with interlocked dampers controlled by a damper motor and airstreamthermostat. Dampers shall be arranged to completely enclose and isolate theheating coil elements when no temperature rise is required. Each coil shall becapable of maintaining a constant discharge air temperature regardless ofvariations in entering air temperatures with rated steam flow.

b. Proportioning of the air shall be such that the temperature at any point in a planeparallel to the face of the coil 3 feet downstream from the leaving side shall notvary more than 5 degrees F from the average discharge airstream temperature.

c. Air volume passing through the coil shall not vary more than 5 percent, regardless

of the position of the internal dampers.d. Finned heating elements shall be fabricated of seamless straight, vertical copper

tubes. Each tube shall be individually secured to the steam and return headers bya brazed joint.

e. Finned elements shall be factory tested at 300-psi water and 1,000 lbs. hydrostaticpressure.

f. The parallel plate fins shall be of either minimum thickness 0.010 inch foraluminum or a minimum thickness 0.008 inch for copper.



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g. Plate style fin surface may be either of low continuous corrugation (10 FPI max)or flat (12 FPI max). Fin edging shall be rippled or straight. All without lancing orother serrated enhancements.

h. Vertical tube orientation is preferred for this type of equipment.

i. Refer to the paragraph entitled Preheat Coils using steam for additionalconstruction requirements.

D. Chilled Water Coil(s):

1. Small units will only be required to provide their standard and standard options in

order to comply with the following criteria.

2. Unless otherwise stated in here see related Sections for additional criteria.

3. All chilled water cooling coils regardless of size and application, shall at minimum befully drainable incorporating vents and drains on all headers. Intermediate headerswhen needed per the application shall also include Vents and Drains.

4. The parallel plate fins shall be a minimum thickness of 0.010-inch aluminum or aminimum thickness of 0.008-inch copper when specifically required.

5. Fin surface may be either of low continuous corrugation i.e.) peak-to-valley height shallnot exceed 0.065 inches at 10 FPI maximum or flat at 12 FPI maximum. Fin edgingshall be rippled or straight. Surface and edging shall not have lancing or other serratedenhancements.

6. Die formed intermediate tube supports with oversized ID tube collars or with brass ornylon grommets shall be used when finned tube lengths equal or exceed 60 inches.

7. Coils shall use 5/8-inch nominal OD copper with a minimum 0.035-inch wall thicknessfor tubes and return bends.

a. Use 90/10 cupro-nickel tubes and return bends with 0.032-inch wall thicknesswhen specified on the Schedule.

8. Coils may use 1/2-inch nominal OD copper and return bends with minimum 0.032-inchwall thickness when circuiting design for the water velocity range cannot be met. Allother design conditions, Codes and Standards shall still apply.

a. Use 90/10 cupro-nickel tubes and return bends with minimum 0.028-inch wallthickness when specified on the Schedule.

9. All coil circuiting shall allow for free and complete draining and venting.

10.All headers shall use copper or red brass. Each header shall have a vent and a drain.

a. Each vent and drain shall be individually extended through the unit-housing walland constructed complete with shut-off valve and cap. Contractor providing coilshall be responsible for proper grommeting / gasketing at wall surface penetrationto prevent air leakage to pass leakage tests. Contractor providing Unit withFactory installed Coil(s) shall coordrinate with Manufacturer to meet intent.

b. Alternatively with submittal approval, each vent and drain shall be constructedcomplete with shut-off valve and cap individually extended and routed andpointed into respective drain pans and be easily and quickly reachable bymaintenance staff.

11.All coils shall have same end connections regardless of the number of rows deep ofthe respective coil (with the exception of special application pre-approvedapplications such as opposite end steam coil(s).

12.Coils shall be rated in accordance with ARI standard 410. Cooling Coils shall be basedon the following unless otherwise specified in the Coil Schedule on the Drawing:

a. Entering water temperature shall be 43 degrees F. The leaving water temperatureshall be 59 degrees F or higher.



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b. Air velocity through the coil face area shall not exceed 500 fpm for 6 or 8 fpi (finsper inch), 475 fpm for 10 fpi, 450 fpm for 12 fpi.

c. Water velocity shall not exceed 5 feet per second nor be less than 2.4 feet persecond under design conditions.

13.Air pressure drop for the cooling coil(s) shall not exceed that referenced in theSchedule under design conditions unless pre-approved in writing from Owner.

14.Water pressure drop shall be measured at the leaving and entering connectionswhether a single or stacked coil arrangement is used and shall not exceed an

equivalent head of 30 feet water column unless specifically stated in the Schedule.15.[Note to AE: Unless a Design Phase pre-approved variance is authorized in writing

from Owner], the following shall apply:

a. Selection shall be a minimum of 8 rows when involved with 100 percent outdoorair.

b. Selection shall be a minimum of 6 rows for recirculated air units or with no morethan 20 percent of the total air volume as outdoor air.

c. Selection shall be a minimum of 4 rows for recirculated air units that also receivesventilation air fully preprocessed by a Dedicated outdoor air unit (typicallyincorporating a Total Enthalpy Energy Recovery Wheel).

d. All other conditions shall refer to the respective job parameters and subsequent

schedule and shall not conflict with this subsection or ASHRAE 90.1.

16.Each fully constructed coil in their entirety shall be tested with 325 pounds pressure ofcompressed air under water. Coils shall be designed for operation at 250 psig. designworking pressure and up to 300 degrees F.

E. Reheat Coil Section and Reheat Coil: (Excluding Booster Coils)

1. See also Section 23 73 23 Custom Air Handling Unitfor additional criteria.

2. A reheat coil shall be used when re-heating of the conditioned (dehumidified) airtemperature leaves the cooling coil below 55 F db.

3. Based on having individual or branch reheat coils designed to boost air temperaturefrom 55 F db, a Central Station type reheat coil shall be required when it is necessaryto re-heat the conditioned (dehumidified) air to 55 F db prior to leaving the AHU.

Unless otherwise specified in the Drawing Schedule, the required temperature leavingthe cooling coil is typically 55 F db.

a. Physical reach in or walk in access is required between all coils via full sizedhinged and latched access door(s) (if available for small units else panels) asdescribed in the access section.

b. For purposes of "cleanability" and minimizing air pressure drop, a maximum 12FPI may be used with flat fin surface, or with a maximum 10 FPI using lowcorrugation.

4. Generally, vertical steam coils are preferred for applications requiring duct or airhandling unit widths greater than 96 inches. Non-vertical reheat coils may be selectedwith tube lengths not to exceed 10 feet for nominal 1-inch outer tube design and 8 feetfor nominal 5/8 inch outer tube design of finned copper tube with aluminum plate fins.

a. If vertical tube orientation is used, design the system for adequate vertical drop forcondensate so as to avoid logging the coil with condensate.

b. Special care shall be taken in sizing all steam coils where modulating control isused so as to obtain even distribution of steam under light heating loads and toprevent stratification of air temperatures.

c. Modulating control shall only be considered for coils with above freezing inlettemperatures.



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d. Parallel 1/3 and 2/3 or parallel 1/3 and full sized control valves are preferred foroptimum modulating control.

e. All steam based modulating coils shall be provided with vacuum breaker and trapdischarge legs with sufficient vertical drop to clear the coil of condensate liquidunder all operating conditions.

5. Reheat coils can use either hot water or steam. In either case, the fins shall be flat ornearly flat i.e.) peak-to-valley height shall not exceed 0.065 inches with a minimumthickness of 0.010-inches.

a. Steam coils shall be distributing type (with tubes pitched in casing when verticaltube orientation is not available). Tubes and headers shall be copper. The outertube shall be a nominal 1-inch diameter with a minimum of 0.049-inch wallthickness. The inside tube shall be a nominal 5/8-inch diameter with a minimumof 0.035-inch wall thickness.

b. An acceptable alternate may use a nominal 5/8-inch OD outer condensate tubewith a minimum 0.035-inch wall and the inner steam distributing tube shall be anominal 3/8-inch OD with a minimum 0.020-wall thickness. However, in this case,the maximum tube length (or finned length) shall not exceed 96 inches.

c. If the design uses steam, and unless otherwise specifically scheduled, the coil(s)shall be based on a net steam pressure of 5 psig. The automatic control valve(s)for the same shall be sized not to exceed 2 psig. pressure drop through the valveat maximum steam consumption. Supply connections and gate valves for thecoils shall be not less than one pipe size larger than their respective automaticvalves.

d. When using hot water-glycol mixture, the design may use either a nominal 5/8-inch nominal OD copper with 0.035-inch wall thickness tubes and return bends oruse 90/10 cupro-nickel tubes and return bends with 0.028-inch wall thickness. Or,the design may use a nominal 1/2-inch nominal OD copper and return bends withminimum 0.028-inch wall thickness or 90/10 cupro-nickel tubes and return bendswith minimum 0.025-inch wall thickness.

e. Reheat coil casings and intermediate tube supports may use a minimum of 16gauge galvanized steel G90-U. Refer to cooling coil specifications for physicalrequirements for casings, frames, tube supports, and header and vent extensionsand other related criteria when re-heat coils are located within the same coil

section as the cooling coil(s).f. Physical reach in or walk in access is required between all coils via full sized

hinged and latched access door(s) as described in the access section.

g. A maximum 12 FPI may be used with flat fin surface, or with a maximum 10 FPIusing low corrugation.

F. Booster Coils:

1. See also Section 23 73 23 Custom Air Handling Units for additional criteria.

2. A Booster coil shall be used to aid in conditioning the zoned space when re-heating ofthe conditioned (dehumidified) air is needed to raise the supply air temperaturetypically from 55 degrees F db.

3. Booster coil casings and intermediate tube supports shall use a minimum of 16 gaugegalvanized steel G90-U.

4. Coordinate coil specifications for physical criteria and mounting requirements forcasings, frames, tube supports, and header and vent extensions and other relatedcriteria with the Drawing Schedule.

5. Physical reach in, or walk in access (based on duct size), is required immediatelyadjacent to each coil via full sized hinged and latched access door(s) as described inthe access section.



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6. Booster Coils shall be limited to 60 inch finned length and 30 inch fin height.

7. Fins shall be flat or nearly flat i.e.) peak-to-valley height shall not exceed 0.065 incheswith a minimum thickness of 0.008-inches.

8. A maximum 12 FPI may be used with flat fin surface, or with a maximum 10 FPI usinglow corrugation.

9. Airside velocity shall not exceed 700 FPM. Airside pressure drop shall not exceed0.33-inch w.c.

10.Booster Coils can use either hot water or steam.

a. Distributing type steam coils are preferred, especially when finned lengths exceed45 inches and/or coils are mounted in potentially freezing areas such as non-ventilated perimeter-enclosed spaces that do not also incorporate perimeterheating.

1) Tubes and headers shall be copper. Typically, the outer tube shall be anominal 1-inch diameter with a minimum of 0.049-inch wall thickness. Theinside tube shall be a nominal 5/8-inch diameter with a minimum of 0.035-inchwall thickness.

2) An acceptable alternate may use a nominal 5/8-inch OD outer condensatetube with a minimum 0.035-inch wall and the inner steam distributing tubeshall be a nominal 3/8-inch OD with a minimum 0.020-wall thickness.

3) If vertical tube orientation is used, design the system for adequate verticaldrop for condensate so as to avoid logging the coil with condensate.

4) Unless otherwise scheduled, steam coil(s) shall be based on a net steampressure of 5 psig. The automatic control valve(s) for the same shall be sizednot to exceed 2-psig pressure drop through the valve at maximum steamconsumption. Supply connections and gate valves for the coils shall be notless than one pipe size larger than their respective automatic valves.

5) Modulating control shall only be considered for coils with above freezing inlettemperatures.

6) Special care shall be taken in sizing all steam coils where modulating controlis used so as to obtain even distribution of steam under light heating loadsand to prevent stratification of air temperatures.

7) Parallel 1/3 and 2/3 or parallel 1/3 and full sized control valves are preferredfor optimum modulating control.

8) All steam based modulating coils shall be provided with vacuum breaker andtrap discharge legs with sufficient vertical drop to clear the coil of condensateliquid under all operating conditions.

b. If using hot water, the design may use either a nominal 5/8-inch nominal ODcopper with 0.025-inch wall thickness tubes and return bends or use 90/10 cupro-nickel tubes and return bends with 0.022-inch wall thickness. Or, the design mayuse a nominal 1/2-inch nominal OD copper and return bends with minimum 0.020-inch wall thickness or 90/10 cupro-nickel tubes and return bends with minimum0.020-inch wall thickness.

1) Water-Glycol mixture typically 25 percent by weight may need to be usedespecially when coils are mounted in potentially freezing areas such as non-ventilated perimeter-enclosed spaces that do not also incorporate perimeterheating.

2) Tube side fluid velocity shall not exceed 5 FPS and shall not fall below 0.5FPS during design flow.

3) Tube side fluid pressure drop shall not exceed 20 ft. w.c. and shall typically bein a range of 8 to 10 ft. w.c.



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G. Flange \ Mounting frame:

1. Each section may have either continuous length base structural steel members or eachsection shall incorporate structural steel members. All welding shall be per AWS D1.1standards. If galvanized structures are used, welded seams shall be properly cleanedand painted with zinc rich coating.

2. Duct mounted coils shall use flanges using a minimum of 1-1/2 inch bolt up styleflange.

H. Drain Pan(s):

[Note to AE: See also Section 23 73 23 Custom Air Handling Units for additional}

1. Drain pans are required for cooling coil applications and for other applicationsincorporating fluids that can leak from the coil or coil components impacting finishedareas.

I. Filter Section(s):

[Note to AE:

1. See also Section 23 73 23 Custom Air Handling Unitsand include a Section 23 40 00 Air Cleaning for additional criteria.]

J. Access Section:

1. [Note to AE: See also Section 23 73 23 Custom Air Handling Units for additional

criteria when access sections are required with the coil.]

2.2 GALVANIZED STEEL SHEET

A. G90: First quality, lock former quality (LFQ), cold rolled, open hearth soft steel sheetcapable of double seaming without fracture, ASTM A924 (formerly ASTM A525) or ASTM

A653 (Formerly ASTM A527). Galvanized coating shall be G90. G90 means the totalamount of zinc on both sides is 0.90-oz/sq. ft. (0.45 oz/sq. ft. per side).

B. Painting: Use G90 Galvaneal or Zincgrip where painting is specified.

2.3 COIL SEALANT AND GASKETING

A. Sealant: If sealants are required in order to pass duct or AHU leakage tests, they shalladhere to the following.

1. UL Classified sealant as compounded specifically for sealing joint and seam inductwork. Acceptable manufacturers are Hardcast, United McGill, Mon-Eco Industriesor H. B. Fuller/Foster.

2. Duct tapes are not allowed.

3. Select sealant as recommended by manufacturer for specific application.

4. Submit sealant manufacturers data sheets including performance data, pressureratings, surface burning characteristics data, and manufacturers detailed installationinstructions.

B. Gaskets: If gaskets are required in order to pass duct or AHU leakage tests, they shalladhere to the following.

1. Butyl or polymer based tape similar to Ductmate 440, Ventfabrics Ventlok No. 797 or

799 in flanged joints.2. Gasket material shall be FDA or USDA approved.

PART 3 - EXECUTION

3.1 SOURCE QUALITY CONTROL



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A. Responsibility: Installing Contractor shall be responsible for verifying finishes for receivedmaterials, ensuring finishes are per approved Specifications and have not been altered toappear as other than their respective original design and manufacture as approved by the

AE. Only minor superficial repairs will be conditionally approved by the AE. Relevantreplacement of rejected component(s) shall be required. Components shall not be alteredto appear as other than their respective original design and manufacture as approved bythe AE.

B. Damage or Defects: All Coatings, steel and sheet metal for purposes including but notlimited to framing and surfaces shall be free of kinks, dents, scratches, stains etc. and

shall not exhibit an absence of proper coating or galvanizing before and after assembly.C. Cleaning: Properly clean all components internally and externally prior to assembly

should they be found in any other condition than like new and clean condition.

3.2 FIELD QUALITY CONTROL

A. Inspection And Resolution: Work will be inspected by Owner in accordance with theContract Documents.

3.3 PROTECTION

A. Coordination: Confer with Owner for desired temporary alterations and final hookups.

B. Temporary Protection: All Coils shall be protected with fabricated end caps for end ofthe day runs to prevent dirt or moisture contamination of system during construction.

C. Precaution: Use all reasonable precautions to prevent coil materials from becoming dirty,oily or damaged prior to fabrication and thereafter during construction and anyreinstallation(s). This is to minimize extent of repair, replacement, and subsequentadditional cleaning.

3.4 CONSTRUCTION

A. Craftsmanship: Install coils so that interior surfaces are smooth, matching net internalface area and dimensions for duct-mounted applications and similarly for Central Stationconfigurations.

1. Transitions: [Note to AE: Include a referenced section 23 31 00 Specialty Ductworkand 23 33 00 Air Duct Accessories for providing transitions where different size ordifferent shape ductwork segments are connected.] Unless otherwise indicated, makediverging transitions with a maximum angle of 15 degrees per side (or 30 degrees

total diverging) and 25 degrees per side for converging transitions (or 50 degrees totalconverging) when connecting to bolt-up coils or Coil Sections.

3.5 INSTALLATION

A. Support Requirements: Refer to all Sections within Basic Mechanical Materials andMethods for Mechanical Supporting Devices for additional support requirements includingattachments to structures. All units shall be installed level (in the same dimensionalplane) and as per the Drawings.

B. Dissimilar Metals: Where two dissimilar metals meet, install joint in such a manner thatmetals do not contact each other by using a proper seal, sealant or compound.

C. Outside Air Intakes: Coils \ coil sections immediately adjacent to Filtered, ducted outsideair intakes shall have this duct section pitch toward the intake to drain to the outside of

building. Solder or seal seams to form watertight joints. Blank off all unused portions oflouvers with fabricated insulated panels while still abiding to net free area requirements ofthe louvers. Where complete drainage to the exterior is not possible, construct a stainlesssteel drain pan with piped drain such that all moisture entrained through the louver systemwill be precipitated out of the air stream and drained in this immediately adjacent ductsection. The intent of this paragraph is to prevent any and all moisture from entering theduct system beyond the louver drainage section and prevent any and all moisture fromleaking out and onto interior building surfaces.



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D. Electrical Centers: Do not install Duct mounted or Central Station type coil(s) \ coilsection(s) over electrical panelboards, switchgear, switchboards or motor control centers.

E. Installation of Instrumentation and Control Equipment: Refer to Sections 23 09 13 -Instrumentation and Control Devices for HVAC and 23 09 23 - Building AutomationSystem (BAS) for HVAC.

F. Sealing Requirements: Seams and joint-sealing requirements shall meet SMACNA ClassA.

G. Mechanical Support: Support coil(s) and coil section(s) with removable angles or

channels and fasteners. Make all connections to equipment including equipment furnishedby others. Secure frames with gaskets, nuts, bolts and washers.

3.6 PREPARATION

A. Surface Preparation: With the exception of specialty coated surfaces, prepare surfaceframing by using power sanders or wire brushes to remove incidental materials such asrust and paint.

3.7 REPAIR AND RE-INSTALLATION

A. Paint: Use G90 Galvaneal or Zincgrip where touch-up painting is required to preventrusting of raw edges with the exception of specialty coated surfaces (i.e. coils forexample). Coordinate with the vendor for replacement or repair of specialty coated coilssubsequent to first coordinating with the AE and Owner.

B. Rework: Provide quality work in like manner as initial installation, replacing all damagedcomponents. Install materials conforming to the same criteria as outlined in theseSpecifications and conforming to SMACNA as previously described.

3.8 CLEANING

A. Cleanliness: Standards from National Air Duct Cleaners Association, NADCA for HVAC &Duct Systems shall be utilized for determining the need for and the extent of cleaning thatwill be required. These standards will be used to resolve any related issues.

B. Coordinate: This section with all other related HVAC sections.

C. Cleaning Agents: Use only non-hazardous non-toxic cleaning agents and materials.Provide MSDS cut sheets upon request.

3.9 COMMISSIONING

A. Testing and Balancing: Refer to Section 23 05 93 - Testing, Adjusting and Balancingforrelated Criteria.

B. Coordinate: With the AE and the Owner.

END OF SECTION 238216

This section of the U of I Facilities Standards establishes minimum requirements only.It should not be used as a complete specification.


23 82 16 - Heating and Cooling Coils

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Transcript of 23 82 16 - Heating and Cooling Coils