CAFB Mechanical Standards.pdf

CAFB BASE STANDARDS Mechanical

Mechanical Page 1

GENERAL

a. All mechanical equipment shall be produced by a manufacturer that has a minimum of 5 years of history manufacturing the particular or similar equipment. Said equipment shall be a product normally produced by the manufacturer on a regular basis. The manufacturer shall have the required in-house technical expertise and testing capabilities required to support the products operational and performance requirements.

b. Major mechanical equipment shall be factory tested prior to shipping. Testing and compliance must be documented and submitted. Final acceptable for any project shall not be provided without this testing data.

c. All required items to make the equipment operational and useable shall be provided by the equipment manufacturer.

d. All major mechanical equipment (to include but not limited to fans, air handling units, chillers, direct expansion equip, boilers, all terminal boxes (VAVs, FTBs, etc), preheat and reheat coils, generators, pumps and adjustable frequency drives) as a minimum, shall be included into the existing Base EMCS. Head end graphics must be updated with every renovation.

e. All major mechanical equipment must have acceptable warranties. Warranties shall be included with submittals for approval. Include a minimum, 1 year labor, 5 year parts for all major equipment. All warranties shall be provided from the manufacturer of the equipment where possible, and not offered through third party contractors or installation companies.

f. All underground piping shall have a tracer wire.

g. Underground water pipe shall be buried to a depth of four feet and no deeper.

h. Directional boring is permissible however, it must be accompanied by signed and sealed (by a licensed professional engineer) drawings and calculations, as well as comply with all applicable standards and UFCs. Pit bores are prohibited.

i. Backflow preventers shall be installed no more than five feet above the floor and twelve inches from the wall.

j. All new HVAC automated controls shall be DDC type. All DDC controls shall be capable of being controlled and monitored through the existing base EMCS (Johnson Metasys). Contractor to provide any and all labor and equipment necessary to communicate with existing EMCS.

k. Constant primary, variable secondary pumping systems are preferred. Variable primary only pumping systems will be considered on a case-by-case basis.

l. Cooling load and psychometric calculations must be provided at the 35% submittal to ensure the proper sizing of new equipment. 35% documents will not be approved until this document is reviewed and approved. These calculations are required for all HVAC projects.

m. Final zoning of the HVAC system is the responsibility of the contractor and provided with the 65% submittal.

The contractor must receive written approval from the government on the final zoning plan. 65% documents will not be approved until this document is reviewed and approved.

n. Provide Outside Air (OA) calculations IAW UFC and ASHRAE 62.1 as a part of the 95% submittal. These calculations are required for all HVAC projects.

MECHANICAL INSULATION

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Piping Insulation

a. Domestic hot and cold water installed above ground, shall be insulated with a minimum 1/2 inch mineral fiber.

b. Heating hot water shall be insulated with a minimum 1 inch mineral fiber.

c. Chilled water and dual service water piping shall be insulated with a minimum ¾ inch foam glass, phenolic foam, or fiberglass.

d. Horizontal internal storm drainage piping runs shall be insulated with 1 inch mineral fiber.

e. Exterior chilled water and heating water piping outdoors and above grade shall be insulated with 1 inch foam glass, phenolic foam, or closed cell glass/polyisocyanurate with an aluminum jacket.

f. Buried exterior chilled water, heating water and dual service piping shall be factory fabricated, pre-insulated piping suitable for exterior installation. Insulation shall be urethane with 1 inch minimum thickness. All ferrous metal piping shall have pre-insulated, coated elbows and joints due to a high water table in an effort to mitigate rust and deterioration.

g. Refrigerant piping insulation shall be black, closed cell flexible elastomeric insulation, 1 inch thick.

h. Insulation shall comply with the above requirements or energy efficiency standards, whichever one is more stringent. At a minimum, the insulation thickness, type, and application shall comply with the most current editions of ASHRAE 90.1, MICA National Commercial and Industrial Insulation Standards, and International Energy Conservation Code (IECC).

Ductwork Insulation

a. Concealed supply, return and outside air ductwork shall be insulated with 2-inch thick, 1-1/2 pounds per cubic foot blanket flexible mineral fiber (must meet or exceed an R-8 rating IAW International Energy Conservation Code C403.11.1). Insulation shall be external to the ductwork. Internally lined duct and fiber duct board (when not used as insulation) are not acceptable.

b. Supply, return and outside air ductwork exposed in mechanical rooms shall be insulated with 1-inch thick, 3 pounds per cubic foot rigid mineral fiber board insulation. External insulation only.

c. Ductwork exposed outdoors shall be insulated with 1-inch thick flexible cellular insulation and wrapped with a minimum of 27 gauge aluminum jacket. (must meet or exceed an R-8 rating IAW International Energy Conservation Code C403.11.1)

d. Mastic-plus-embedded-fabric systems are the preferred joining methods for all joints, seams, and connections. Do not use pressure sensitive tape unless previously approved by the Contracting Officer (CO) and Contracting Officer’s Representative (COR).

e. Adhesives and installation of all insulation shall be in accordance with manufacturer’s recommendations.

f. Insulation shall comply with the above requirements or energy efficiency standards, whichever one is more stringent. Insulation thickness shall meet the minimums listed above or the current edition of ASHRAE 90.1, or IECC, whichever is more stringent.

g. All insulation shall comply with NFPA 90A standards.

CHILLED, CONDENSER, OR DUAL SERVICE WATER PIPING

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a. Chilled water and dual service piping 2-1/2 inches and larger shall be Schedule 40 black steel with welded joints. Random Copolymerized Polypropylene (PP-R) and Random Copolymerized Polypropylene High- Crystallinity Resin (PP-RCT) piping typical to Aquatherm “Blue Pipe” is an acceptable alternative to black steel, for both interior and exterior applications. When used in applications for chilled, dual service, or heating hot water, all piping shall be insulated (refer to previous sections for more information).

b. Chilled water and dual service piping 2 inches and smaller shall be type “L” hard drawn copper or PP-R/RCT.

c. Condenser water piping shall be Schedule 40 black steel or PP-R/RCT. Condenser water piping is not required to be insulated, but is required to be provided with UV protection. A minimum of 2-coats of Tnemec paint is required for all exposed black steel condenser water piping. Provide UV protection for the PP-R/RCT in accordance with the manufacturer’s recommendations.

d. End connections to valves and equipment shall be threaded on piping 2 inches and smaller. Pipe ends 2-1/2 inches and larger shall be flanged.

e. External buried chilled water and dual service piping shall be pre-insulated black steel double wall type or PP- R/RCT. If black steel is chosen, the carrier pipe shall be Schedule 40 black steel. Insulation shall be polyurethane with 1-inch minimum thickness. External jacket piping shall be PVC or high density polyurethane. Insulation shall comply with the above requirements or energy efficiency standards, whichever one is more stringent.

f. Gate valves 2-inch and smaller shall be bronze in accordance with MSS SP-80. Gate valves 2-1/2 inch and larger shall be cast iron in accordance with MSS SP-70.

g. Ball valves 2-inch and smaller shall be copper alloy in accordance with MSS SP-110. Flanged ball valves 2-1/2 inches and larger shall be bronze in accordance with MSS SP-72.

h. Butterfly valves shall be cast iron flanged, Type “I” tight shutoff type in accordance with MSS SP-67.

i. Flow measuring devices shall be Venturi type and capable of being read/monitored by the EMCS.

j. All steel/metal piping used on CAFB projects shall be made in America.

PUMPS

a. Pump size and type shall be selected based on maximum efficiency at operating point. Pump shall be non-overloading over range of pump curve.

b. Base- mount, end- suction pumps are preferred for chilled water, heating water and dual service duty.

c. Use double suction pumps on condenser water systems where possible.

d. Use variable frequency drives on pumps in secondary piping and variable primary systems.

e. Pumps shall start/stop manually and through the base EMCS.

f. Flexible connectors shall be used at all pumps and equipment.

g. Inlet and outlet pressure gauges shall be provided on all pumps.

h. Provide one additional unused, and capped, pete’s plug on the pump inlet and outlet of each pump.

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i. Differential pressure shall be provided and monitored at each pump. Equipment must be capable of being read on EMCS.

j. Electric motors shall be NEMA MG-1, premium efficiency.

k. Insulate chilled water pumps with removable, fabricated rigid insulation unit.

PLUMBING SYSTEMS

a. Sanitary waste, vent and storm piping inside the building shall be Schedule 40 PVC. Sanitary waste and storm piping below grade and outside the building shall be PVC (SDR-35).

b. Domestic water piping inside the building shall be type “L” hard drawn copper in accordance with ASTM B 88.

Domestic water piping below slab shall be type “K” soft drawn copper.

PLUMBING FIXTURES

Water Closets: Elongated, wall mounted flush valve type. Provide ASME A 112.6.1M carrier with feet.

Urinals: Vitreous china, wall mounted, siphon jet with ASME A 112.6.1M concealed chair carrier.

Lavatory (Wall Hung): White enameled cast iron as per ASME A 112.19.1M. Provide ASME A 112.18.1M self-closing metering type push button faucets and perforated grid strainers. Faucets shall have insulated traps on wheelchair lavatories. Preferred faucet manufacturer is Delta, model XXXXX.

Lavatory (Counter Mounted): Oval enameled cast iron self rimming type. Self-closing metering push button type, center set faucets. Preferred faucet manufacturer is Delta, model XXXXX.

Service Sink: White enameled cast iron, wall mounted and floor supported by wall outlet cast iron P-trap.

Provide ASME 112.18.1M copper alloy back mounted combination faucets with vacuum breaker and 3/4 inch external hose threads.

Electric Water Cooler: Wall mounted recessed, high/low dual bubbler style, air cooled condensing unit with

4.75 gph minimum capacity. Bubblers shall be controlled by push bars on each side and in front.

Water Heaters - Natural Gas: Commercial grade and in accordance with ASME Boiler and Pressure Vessel Code Section IV and ANSI Z21.10.3. Tanks shall be rated for 150 psi working pressure, ASME stamped and glass or cement lined. Heater shall be insulated with fiberglass insulation. Standby heat loss shall conform to ASHRAE 90.1 high efficiency requirements. Provide ASME “T and P” relief valve.

Water Heaters - Electric: Commercial grade and in accordance with ASME Boiler and Pressure Vessel Code Section IV and ANSI Z21.10.3. Tanks shall be rated for 150 psi working pressure, ASME stamped and glass or cement lined. Heater shall be insulated with fiberglass insulation. Standby heat loss shall conform to ASHRAE

90.1 high efficiency requirements. Provide ASME “T and P” relief valve.

LOW PRESSURE WATER HEATING BOILERS

a. Horizontal steel fire tube type, package unit mounted on a skid–type structural steel base.

b. Forced draft condensing type boiler complying with ASHRAE 90.1 and MIL-B-17452.

c. Burner shall include interrupted pilot type ignition system or other energy efficient type. Combustion control system shall be the positioning type. Burner controls and safety equipment shall conform to requirements of MIL-B-18796.

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d. Boiler trim shall comply with ASME Boiler and Pressure Vessel Code Section IV and MIL-B18796.

Provide an emergency disconnect switch on wall outside boiler room entrance.

e. Provide draft and venting in accordance with manufacturer’s recommendations.

f. Preferred boiler manufacturer is Cleaver Brooks.

g. Boiler shall have the capability to be controlled and monitored via the base EMCS system. Contractor to provide any and all labor and equipment necessary to communicate with existing EMCS.

CENTRAL REFRIGERATION EQUIPMENT

CHILLERS: When building/space loads are over 20 tons, chillers are to be incorporated into the design.

Otherwise, packaged DX unitary outdoor/rooftop equipment shall be used.

a. 20 Tons to 70 Tons:

Air cooled, self- contained chillers with hermetically sealed scroll type compressors. A minimum of two compressor circuits shall be provided. Chiller shall be in accordance with ARI–550. Refrigerant shall have an Ozone Depletion Factor (ODF) of 0.05 or less. No more R-22 equipment shall be installed. Preferred refrigerants are R-134a and R-407c. Preferred manufacturer is Daikin/McQuay.

b. 70 Tons to 200 Tons:

Water cooled chiller with helical rotary (screw – type) compressors. A minimum of two compressor circuits must be provided. Chiller shall be in accordance with ARI–550. Compressors shall be capable of operating stably at 10 percent of full load. Refrigerant shall have an Ozone Depletion Factor (ODF) of 0.05 or less. Chiller shall have factory installed purge system. Preferred manufacturer is Daikin/McQuay

c. 200 Tons and Larger:

Water cooled centrifugal chillers. Compressors shall be capable of operating stably for indefinite periods of time at any stage of capacity from 100 to 10 percent of load. Chillers shall be in accordance with ARI-

550. Chiller shall have factory installed purge system. Preferred manufacturer is Daikin/McQuay

d. Chillers shall include factory control panels and starters that are compatible with the existing Base EMCS.

e. Chillers shall have the capability to be controlled and monitored via the base EMCS system. Contractor to

f. All chillers shall meet or exceed the efficiency ratings within the current editions of ASHRAE 90.1 and the

IECC.

COOLING TOWERS

a. Open distribution type and factory assembled in accordance with FS-A-A-59223. Constructed of appropriate material for the service conditions with PVC fill. FRP construction is preferred.

b. Fan motor shall be direct drive with a variable frequency drive. Motor, fan, and controls shall be located out of evaporation air stream.

c. Condenser water circuit shall include a bypass valve to dump bypass water into the tower sump when required.

d. Provide automatic feed chemical treatment.

e. Provide factory ladders and handrails.

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f. Make-up water shall have bubble type full shut-off valve.

g. Provide factory installed air inlet screens to prevent birds and trash from entering tower. Screen material shall be stainless steel.

h. Cooling towers shall have the capability to be controlled and monitored via the base EMCS system.

Contractor to provide any and all labor and equipment necessary to communicate with existing EMCS.

AIR HANDLING EQUIPMENT

AIR HANDLING UNITS

a. Air handling units shall be factory insulated, double wall type in accordance with ARI 430 with sound ratings in accordance with ASHRAE 68. All sections of AHUs shall be factory built. Field built plenums are not acceptable.

b. Fans shall be centrifugal type with airfoil blades where possible.

c. New air handling units shall be variable volume type plenum fans with variable frequency drives.

d. All new chilled water air handling units shall include an airside economizer where required by energy efficiency standards or economical.

e. Coils shall be in accordance with ARI 410. Drain pans shall be stainless steel and provide positive drainage. Coil clearances shall be clearing indicated on the drawings. Design/locate the AHUs to prevent interference in this clearance to the greatest extent possible.

f. Airflow through coils shall not exceed 450 FPM. Provide at least 16” of clearance between coils.

g. Serpentine temperature sensors shall be used in lieu of single point, probe type.

h. Access doors shall be provided in all sections and in between coils. Doors shall not be less than 12” in any one direction, however full section access is preferred.

i. AHUs shall have the capability to be controlled and monitored via the base EMCS system. Contractor to

VARIABLE AIR VOLUME (VAV) TERMINAL UNITS

a. VAV units shall be in accordance with ARI 880. Maximum allowable air leakage rate shall be 2 percent at three-inch water gauge.

b. Casings shall be minimum 26 gauge galvanized steel. Provide access panels where required for service and adjustment without disconnecting ducts.

c. Boxes shall be of double wall construction. Insulation shall be a minimum of 1/2 inch, 1-1/2 lb. per foot density.

d. Damper must maintain constant position / cfm within 5 percent of design rated cfm setting.

e. Re-heat hot water coils shall be one-row or two-row, as required and an integral part of the box.

f. VAV units shall be of the pressure independent type and capable of 100% airtight shut-off.

g. Cable or “Worm-gear” style damper/valve control is not acceptable.

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h. VAVs shall have the capability to be controlled and monitored via the base EMCS system, therefor only

DDC controlled boxes are allowed (no pneumatically controlled boxes). Contractor to provide any and all labor and equipment necessary to communicate with existing EMCS.

UNITARY AIR CONDITIONING EQUIPMENT

PACKAGE TERMINAL UNITS

a. Unit shall have a minimum efficiency in accordance with ASHRAE 90.1. Provide units removable from the inside of the building for servicing without removing the outside cabinet.

b. Units shall have integral electric resistance heaters, ARI certified and UL listed.

c. Indication and controls shall be connected to the Base EMCS system where practical. Provide alternate design (for pricing) to include monitoring/control of equipment 5 tons and smaller.

SINGLE PACKAGE UNITS

a. Units shall have minimum efficiency in accordance with ASHRAE 90.1.

b. Units shall be combination heating and cooling units with direct expansion cooling, gas heat and tested in accordance with ARI 210/240.

c. When provided for rooftop installation, the units shall include factory roof curbs, flashing and transition plenum.

d. All electrical disconnecting means must be provided outside of the unit and not integral to the unit. If the manufacturer does not offer the capability to remove this feature from the factory, a separate disconnect shall be provided.

e. When building / space loads are over 20-tons, chilled water systems are preferred.

f. Packaged units over 5 tons shall have the capability to be controlled and monitored via the base EMCS system. Contractor to provide any and all labor and equipment necessary to communicate with existing

EMCS.

SPLIT SYSTEM TYPE

a. Minimum efficiency shall be in accordance with ASHRAE 90.1.

b. Provide separate assemblies designed to be used together and operate in accordance with ARI 210/240.

c. When building / space loads are over 20-tons, chilled water systems are preferred.

d. DX split systems over 5 tons shall have the capability to be controlled and monitored via the base EMCS system. Contractor to provide any and all labor and equipment necessary to communicate with existing

EMCS.

DUCTWORK

a. All ductwork shall be installed in accordance with SMACNA HVAC Duct Construction Standards. Duct air leakage tests shall be performed.

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b. All ductwork shall be externally insulated.

c. Kitchen grease exhaust duct shall be 16-gauge welded black steel or 18-gauge welded stainless steel.

d. Kitchen dishwasher exhaust shall be stainless steel.

e. Shower exhaust ductwork shall be aluminum or stainless steel.

f. Provide sufficient number of access panels to permit easy access for cleaning of ducts.

g. Mastic-plus-embedded-fabric systems are the preferred joining methods for all joints, seams, and connections.

Do not use pressure sensitive tape unless previously approved by the Contracting Officer (CO) and Contracting Officer’s Representative (COR).

CONTROL SYSTEMS

a. All controls shall be compatible and communicate with existing Base EMCS. Existing control system is a

Johnson Controls Metasys system.

b. All new construction shall utilize DDC control systems. Pneumatic controls are not acceptable. Wireless DDC controls systems are not allowed on any projects.

TEST, ADJUSTING, AND BALANCING (TAB) FOR HVAC

a. A Test & Balance (T&B) must be performed for all HVAC equipment/projects. This shall include but is not limited to:

a. Chillers

b. AHUs

c. DX equipment (greater than 5 tons)

d. Boilers

e. Fans

f. Pumps

g. Duct

h. VAVs/FTBs/Terminal Boxes

i. Diffusers/Grilles/Registers

j. Chilled and Heating Hot Water flow at all equipment

k. Heat exchangers

l. Energy Recovery Equipment

b. TAB companies and their representatives for CAFB projects must be certified Associated Air Balance Council

(AABC) members or certified by the National Environmental Balancing Bureau (NEBB) to perform TAB service for HVAC, water balancing and vibrations and sound testing of equipment.

c. One or more of the applicable AABC, NEBB or SMACNA publications, supplemented by ASHRAE Handbook "HVAC Applications" Chapter 38, shall be the basis for planning, procedures, and reports.

d. TAB contractor must supply the following for review and approval:

a. Systems inspection report on equipment and installation for conformance with design.

b. Duct air leakage test report.

c. Systems readiness report.

d. Intermediate and final TAB reports covering flow balance and adjustments, performance tests, vibration tests and sound tests.

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e. Include in final reports uncorrected installation deficiencies noted during TAB and applicable explanatory comments on test results that differ from design requirements.

e. TAB contractor must submit the completed T&B report prior to final or partial final inspection.

COMMISSIONING OF HVAC SYSTEMS

a. All HVAC projects shall be commissioned IAW UFC and UFGS.

b. The level of commissioning services will differ for every project based upon complexity and needs therein. The expectation is that all HVAC systems will be commissioned, but the final requirements and scope will be coordinated with the CO/COR/Base Mechanical Engineer prior to the submission of a fee for design or construction services.

c. The intent of providing commissioning services for HVAC are twofold: The first is to ensure CAFB HVAC projects are of sound design and are appropriate for the region and facility being served. The second is that the HVAC equipment operates as designed and IAW the sequences, schematics, and specifications.

d. The Commissioning Firm shall be an integral part of the project from the NTP of design or construction services and shall see the project through to completion. The Commissioning Firm that provides design review of a project shall be the same that verifies the operational status and correctness of the completed construction project. Every effort shall be made to retain the Commissioning Firm for the life of the specified project, design to final completion.

e. Provide a Commissioning Firm that is certified in commissioning by one of the following: the AABC commissioning Group (ACG); the National Environmental Balancing Bureau (NEBB); the International Certification Board/Testing, Adjusting, and Balancing Bureau (ICB/TABB), the Building Commissioning Association (BCA); the Association of Energy Engineers (AEE). The Commissioning Firm may employ a commissioning professional certified by the University of Wisconsin-Madison or the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) as an alternative to certification of the Commissioning Firm. The Commissioning Firm must be certified in all systems to be commissioned to the extent such certifications are available from the certifying body. Describe any lapses in certification or disciplinary action taken by the certifying body against the proposed Commissioning Firm or Lead Commissioning Specialist in detail. Any firm or commissioning professional that has been the subject of disciplinary action by the certifying body within the five years preceding contract award is not eligible to perform any duties related to commissioning. The Commissioning Firm must be a 1st tier subcontractor of the General or Prime Contractor and must be financially and corporately independent of all other subcontractors.

The Commissioning Firm must employ a Lead Commissioning Specialist that coordinates all aspects of the commissioning process.

f. Comply with the requirements of the commissioning standard under which the Commissioning Firm and Specialists qualifications are approved. When the firm and specialists are certified by BCA, AEE, ASHRAE, or the University of Wisconsin-Madison, comply with the requirements of one of the acceptable standards unless otherwise stated herein. The acceptable standards are ACG Commissioning Guideline, NEBB Commissioning Standard, SMACNA 1429, or ASHRAE 202.