9_Nellis-Creech Mech-Plumb Req 2020-07-07.pdf

NELLIS AND CREECH AFB

INSTALLATION FACILITIES STANDARDS (IFS)

MECHANICAL & PLUMBING REQUIREMENTS

07 JUL 2020

This document is an appendix to Nellis & Creech Air Force Bases IFS which is located here:

https://www.wbdg.org/ffc/af-afcec/installation-facilities-standards-ifs/nellis-creech-afb-ifs

1. Design Conditions:

a. Cooling Design: 0.4 % cooling design dry bulb is 117 deg F at WB temp of 67.6 deg F.

b. Heating Design: 99.6 % heating dry bulb temp is 28.2 deg F (99 percent temp is 31.5 deg F).

c. Summer Cooling Tower Designs: 0.4 percent evaporation wet bulb at a mean coincident dry bulb of 72.5 deg F wet bulb at 95 deg F dry bulb.

d. Altitude above sea level: 1,900 feet.

2. General Requirements:

a. Design of mechanical systems shall take into consideration all factors that will ensure a quiet, comfortable, and appropriate environment for the occupants.

b. Meet requirements of UFC 1-200-02 High Performance and Sustainable Building Requirements. Perform a Life-Cycle Cost Analysis (LCCA) for all projects to determine facility HVAC design.

c. Acoustical impact to building occupants shall be considered when designing the mechanical systems.

3. Special System Criteria:

a. Provide air conditioning and ventilation for proper operation of computers, equipment, machinery, etc.

b. Provide for the ventilation of mechanical rooms where refrigerant may be present.

c. Reference TRANE application engineering manual “Refrigeration Equipment Room

Design” (REF-AM-2, AUG 1992).

4. Maintenance Considerations:

a. Each piece of equipment shall be installed so it can be properly maintained.

b. Clearances shall be provided around all equipment to allow it to be serviced, removed, and replaced as required.

c. Plans and specifications should be examined to minimize large maintenance costs in the future.

d. Provide convenient access to all utilities, cleanouts, HVAC equipment and systems, and gas fittings, in the mechanical room, underground and in the building.

e. Work performed in the overhead ceiling plenum space is to be completed with the least disruptions to building occupants and mission.

f. Provide direct vehicular access to mechanical rooms, if possible.

g. Ensure adequate means of removing interior equipment without demolition.

https://www.wbdg.org/ffc/af-afcec/installation-facilities-standards-ifs/nellis-creech-afb-ifs

h. Construction contract shall include training for base maintenance personnel so they are able to maintain and service all installed equipment. Length of training shall reflect the complexity of each system.

i. Training shall be recorded and four DVD copies of the training shall be provided to the Base Civil Engineer (BCE) office.

5. Corrosion Control / Cathodic Protection:

a. Apply cathodic protection on all buried or submerged ferrous piping, tanks, and related facilities.

b. Under no circumstance will underground facilities be installed without cathodic protection. This requirement includes ferrous materials such as cast iron.

c. All buried or submerged cast iron pipe joints shall be bonded with number 2 AWG insulated wire.

d. Thermite wire connections shall be coated.

e. All cathodic protection design must be performed by an engineer accredited by the

National Association for Corrosion Engineers (NACE).

f. All cathodic protection design shall be based upon specific field tests made at the construction site. Tests will include soil resistivity and water conductivity.

g. Cathodic protection systems shall be sacrificial anode or impressed current and shall comply with corrosion protection criteria outlined in NACE Standard RP-01-69-9 (revised), ETL 87-3, AFM 88-45, AFI-105 and UFC 3-570-06 O&M.

6. Potable Water Source:

a. Coordinate with the Base Civil Engineer (BCE) office for location of water mains and operating pressure ranges in the area of connection. Contractor or designer shall verify existing flows and pressures.

7. Piping Materials and Special Outlets System-Material:

a. Water (Underground): PVC type C-900

b. Water (Aboveground, Outside): Galvanized Steel

c. Water (Aboveground, Inside): Hard Copper Type 1

d. Sanitary Drain, Waste (Building, Three Stories and Less): ABS or PVC-vent sanitary sewer

e. Sanitary Drain, Waste (Buildings taller than Three Stories): Cast Iron

f. Storm Drain: RCP only

g. Chilled Water PVC: Schedule 80 or Hard Copper, Type L

h. Heating Hot Water: Schedule 40 black steel or hard copper, Type L

i. Natural Gas (Underground): Polyethylene with tracer wire

j. Natural Gas (Aboveground): Black Iron

k. Provide dielectric union when connecting dissimilar metals.

l. Provide lead-free plumbing components.

m. Provide identification labels for pipes in mechanical rooms.

n. Label all flow directions.

8. Piping System:

a. Provide valves to isolate portions of building to avoid shutdown of entire building when performing repair and maintenance.

b. Energy conservation washer-less fixtures shall be all metal construction, not chrome-plated plastic. All techniques shall be considered, including 1 GPM or lower-flow restrictors for faucets, 0.5 to 2 GPM low-flow shower heads, single control mixing type faucets, low-volume flush water closets, and self-closing faucet valves. Low-flow fixtures shall meet the standards of EPA Water Sense. Showers shall have valves with pressure balance feature. Provide freeze-proof wall hydrants and interior wall access. Provide wall-mounted drinking fountains with integral bottle filling stations.

c. In buildings that will be normally occupied by more than 15 persons, provide separate toilet rooms for each sex; position them together and use a common wall for plumbing chase. In buildings occupied by 1-15 persons, a single toilet to serve both sexes may be provided. Furnish one water closet, one lavatory, and a room door that can be locked from the inside.

d. All applications of plumbing fixtures shall be considered for usage by people with disabilities, as directed by the Architectural Barriers Act (ABA) Standards.

e. Consider the inclusion of shower facilities.

f. Plumbing fixture types: Note the plumbing code defined maximum flow rates and consumption for all types of plumbing fixtures.

o Water Closets (Institutional): Flushometer valve, siphon-jet, elongated bowl, top supply spud, floor or wall mounted, minimum 1.5 gpm/flush. Seat: plastic, elongated, open front.

o Water Closets (ADA-Compliant, Institutional): Top rim of bowl shall be 18-inches above the floor. (All others same as previous).

o Lavatories (Institutional): Enlarged cast iron or vitreous china, counter top. Faucet: as required.

o Urinal (Institutional): Wall hung. Siphon-jet or washout. Minimum 1 gpm/flush Waterless type urinals should be installed where proper maintenance of the units can be provided.

o Kitchen Sinks (Institutional): Single or double bowl. Ledge back with holes for faucet and spout. Enameled cast iron, porcelain enameled steel or stainless steel.

Faucet: As required.

o Service Sinks (Institutional): Enameled cast iron. Trap Standard, wall or floor mounted. Faucet: As required.

o Food Service Sinks (Institutional): Stainless steel with drain board. Faucet: As required.

o Water Coolers (Institutional): Self-contained. Exposed surfaces shall be stainless steel. Wall mounted surface. Wall mounted semi-recessed. Wall mounted recessed.

ADA-compliant; free standing.

o Showers (Institutional): Wall mounted for stall or bathtub. Valves as required.

9. HVAC:

a. Air conditioning units shall be Carrier or Trane. Chiller units shall be Carrier. Units shall be designed for an ambient temperature of 117 deg F.

b. Variable Refrigerant Flow (VRF) systems are prohibited due to limited maintenance capabilities of base maintenance shops. Other systems shall be used to provide heating and cooling.

c. Wi-Fi-enabled mechanical equipment is prohibited due to security issues.

d. Provide Variable Air Volume (VAV) systems in new projects and in major renovations where entire mechanical system is being replaced.

e. HVAC unit(s) installed to provide 10 tons or greater of cooling to one area shall be connected to the base-wide Energy Management and Control System (EMCS).

f. Provide water cooled chillers for units greater than 40 tons.

g. Variable Frequency Drives (VFDs) shall be installed on HVAC pumps and air handling equipment where appropriate to reduce HVAC energy consumption during off peak periods. VFDs shall be monitored and controlled via the Johnson Controls EMCS and be installed in climate controlled mechanical rooms.

h. Utilize demand ventilation controls where appropriate. Demand ventilation controls include CO2 sensors and operable damper systems (economizers) to limit the amount of outside air admitted into the building to meet the actual requirements of the facility as determined by the CO2 sensors in the return air handling units.

i. Roof mounted mechanical equipment is prohibited. However for some renovation projects and unavoidable configurations, roof equipment may be allowed on a case basis per BCE office approval.

j. All mechanical equipment shall be screened from view and easily accessible for maintenance.

k. Around all equipment, provide a safe environment for maintenance personnel meeting all OSHA requirements.

l. Fresh air intake shall be at least 10 feet above ground level and meet ATFP requirements.

m. Provide natural gas heating where natural gas is available. Confirm availability at start of project. Typically do not install heat pumps when natural gas is available.

n. Provide screw type compressors for chillers greater than 40 tons up to 450 tons.

Provide centrifugal chillers at higher efficiencies for chillers larger than 400 tons.

o. Provide economizer when appropriate.

p. Provide water treatment for all water systems, heating or cooling. These systems shall be maintenance free systems. Systems should have loops installed as part of the system.

q. Provide washable pleated air filters.

r. Provide phase protection for all HVAC equipment (i.e. pumps, chillers, air handling units).

s. Refrigerant shall be hydro chlorofluorocarbon (HCFC) type only.

t. Provide recommended manufacturing clearance around boilers, chillers, pumps, and air handlers for maintenance purposes.

u. Provide external ductwork insulation, not fiberglass duct liner inside of duct.

v. If LNG or propane tank is provided for a facility it shall be located at least 50 feet from facility and enclosed by CMU screen walls.

w. Provide fan speed controls (2-speed or variable speed) for cooling tower fans.

x. Consider variable flow and/or variable speed chillers to minimize pumping and compressor power requirements.

y. Access to equipment for servicing is an extremely important consideration when designing new systems. Consider servicing and removal of coils, filters, valves, pumps, and tubes during design.

z. Exterior equipment shall be hidden from view.

aa. For all projects Contractor shall balance and test the air and hydronic HVAC systems. This includes projects where HVAC system has been modified, repaired, and/or replaced.

10. HVAC Controls:

a. Provide Direct Digital Controls (DDC) that are manufactured by Johnson Controls and part of the Metasys System. DDC shall have direct communication with base

EMCS.

b. Existing base EMCS is Johnson Controls Metasys System, which is a microprocessor-based network installed on the base LAN and designed for maintenance management, trouble-shooting, and energy management. The system is comprised of a network of stand-alone units, each capable of DDC and supervisory control with direct LAN connection accessible by any desktop computer with appropriate software installed. The system allows for the base to perform manual operation, coordinate systems for energy reduction, view facility status in real time and generate run-time reports on equipment.

c. Provide a fully labeled control schematic that details all set points, throttling ranges, actions, spaces, proportional bands, and any other adjustment.

d. Provide a fully labeled elementary diagram (ladder diagram).

e. Provide a sequence of control on drawings cross-referenced to the control schematic and elementary diagram.

f. Provide a generic, functional description of each control component shown on the drawings.

g. Provide for remote monitoring, including advance meters, HVAC, generators, etc.

Use remote sensors so that controllers can be centrally located in the mechanical room.

h. Provide logical grouping of controllers, adapters, relays, and power supplies in an easily accessible controls cabinet mounted away from vibrating machinery.

i. Provide electronic system terminal strips cross-referenced to the control schematic to facilitate troubleshooting and calibration. Maximize “self-help” software.

j. Provide control schematic, elementary diagram, control sequence, description of components, control panel details, legends and schedules in the design.

k. All possible “clog” points shall have differential pressure checks on them.

l. Connect all HVAC controls to JCI Metasys System. Building Systems shall be fully functional on their own in case connection to main EMCS is lost.

m. Drawings shall identify all confined spaces.

11. Heating:

a. Designer shall perform LCCA and select most appropriate heating system for the facility.

b. Use ASHRAE Standards for calculating heating loads.

c. The use of cast iron boilers is prohibited. Provide boiler water testing sample points on all hot water systems. Provide chemical feeding systems on all hot water heating systems. Provide automatic, pilotless, ignition systems on all gas-fired equipment.

Install thermostats on heating supply and return lines. Install pressure gauges with valves on suction and discharge lines to all pumps. Install gas pressure gauges with valves on all gas trains on boilers.

d. Consideration should be given to electric boilers due to Clark County requirement for construction and operating permit for natural gas fueled boilers and their emissions.

e. Where humidification is required, steam humidifiers shall be used.

f. The fuels available for use are natural gas for furnaces and boilers, and electric for heat pumps.

g. Equipment types to be used:

o Type-1: HVAC boilers smaller than 3,000 mbh shall be steel tube condensing type with a minimum 90 percent efficiency at worst-case design conditions. Domestic hot water boiler shall be copper tube.

o Type-2: Heat exchanges shall be shell and tube type or plate type.

o Type-3: Heat pumps shall be air-to-air or water-to-air.

o Type-4: Circulating pumps shall be centrifugal base mounted, inline horizontal or vertical.

o Type-5: Unit heaters shall be horizontal or vertical.

o Type-6: Air handling units shall be blow through or draw through packaged type.

o Type-7: Fan coil units shall be horizontal, vertical, or through-the-wall type. Fan

Coils shall have bleeder ports on all units with isolation valves before the bleeders, canvas connection on return and supply duct connection, and filters shall be built on return registers.

o Type-8: Radiant heaters shall be gas-fired combination.

i. Distribution piping and ducting shall be in accordance with the Uniform

Mechanical Code (UMC), Sheet Metal and Air Conditioning Contractors National Association (SMACNA), and applicable ASHRAE design criteria. Flexible duct runs shall be limited to 5 feet in length.

j. All piping installed to serve building and within building shall be thermally insulated IAW the latest edition of ASHRAE 90.1 Energy Conservation.

k. No asbestos-containing materials shall be used in equipment or insulation.

l. For heating plant and systems, water softeners and water treatment equipment, verify water softeners are properly sized to allow soft water to be introduced into the plant at all times, including emergency shutdown. Provide soft/conditioned water for all large boiler systems. Install adequate water treatment equipment on boilers/plant.

12. Ventilation / Air Conditioning / Refrigeration System:

a. Evaporative coolers shall be installed at the 2-foot to 3-foot level. Select air-cooled condensers based on 117 deg F ambient temperature. Central mechanical systems shall normally be provided unless Life-Cycle Cost Analysis (LCCA) indicates sub systems to be more economical.

b. LCCA shall be completed for air-cooled and/or water-cooled chillers. Larger air conditioning units work more efficiently with cooling towers. Use of a screw type compressor chiller may be more efficient for chiller sizes of 40 to 450 tons.

Centrifugal chillers are typically long lasting.

c. Access to equipment for servicing shall be an important consideration when designing new systems. Removal or servicing of coils, filters, valves, pumps, and tubes shall be considered when designing mechanical systems.

d. Exterior equipment shall be hidden from view and not located near main entry of building.

e. Equipment shall not be located on roof.

f. Chillers shall have Integral/Storage buffer tank.

g. Mechanical refrigeration shall be fueled by electricity.

h. Equipment shall be suitable for the application:

o Type-1: Chillers shall be packaged air-cooled type or water-cooled screw or centrifugal type.

o Type-2: Evaporative coolers shall be up-blast, or vertical-discharge closed-circuit type, or cellulose material impregnated with anti-rot salt and rigidifying saturants.

Media efficiency shall be 76 percent at 600 FPM face velocity with no entrainment of pad water. Open evaporative coolers shall be designed to provide an indoor temperature of 80 deg F.

o Type-3: Heat pumps shall be air-to-air, water-to-air, or geothermal closed loop.

o Type-4: Circulating pumps shall be centrifugal base mounted, inline horizontal, or vertical.

o Type-5: Air handling units shall be flow through or draw through packaged type.

o Type-6: Fan coil units shall be horizontal, vertical, or through-the-wall type. Fan

Coils shall have bleeder ports on all units with isolation valves before the bleeders, canvas connection on return and supply duct connection, and filters shall be built on return registers.

i. All occupied spaces shall have air conditioning. All mechanical rooms, electrical rooms, and telecommunication rooms shall have air conditioning.

j. Air conditioning system shall be chosen on the basis of economy, efficiency, and ease of maintenance.

k. When calculating cooling loads, use ASHRAE standards.

l. The peak or maximum cooling load for selecting the room side cooling equipment will consist of the following but no limited to:

o Exterior heat gain through building construction;

o Personnel occupancy;

o Electrical lighting not to exceed one watt per square foot for rooms and 1.5 watts per square foot for office and shop space;

o Design occupancy ventilation air total heat (outside air design minimum room design condition);

o 10 percent safety factor

m. Window shading devices on the exterior and interior shall be implemented in an effort to reduce the room solar heat gain.

n. Minimum room supply air rate or fan-coil capacity shall be 0.80cfm/sq.ft.

o. The building peak or block cooling load for central refrigeration capacity will be determined on the identical parameters outlined above with the following exceptions:

o Personnel occupancy will be 40 percent total occupancy;

o No interior electrical lighting;

o 10 percent minimum safety factor to include motor horsepower and heat gain to coolant distribution system.

p. Chilled water supply temperature will normally vary between 40 and 50 deg F, which shall be determined from the designer’s analysis of the optimum balance for the cooling unit, water distribution, and water chiller.

q. Normal air infiltration should be evaluated in an effort to meet the requirement for range hood exhaust.

r. The building peak heat gain analysis shall include the personnel ventilation rate or continuous restroom exhaust where the air flows through the occupied space.

s. Provision shall be made for removal of equipment for maintenance. Tube bundles shall have provision of easy removal for maintenance (i.e. A-frame or monorails structurally adequate to support the loads and provide proper distance between system components and walls to ensure ability to clean, repair, or replace tube bundles).

t. Install bypasses on all strainers to allow cleaning without plant shutdown.

u. Distribution piping and/or ducting specification shall be the same as for heating.

v. Design conditions shall be per ASHRAE unless stated elsewhere in IFS. Ventilation requirements shall be per ASHRAE.

13. Utilities / Pipelines:

a. Fire hydrants shall be dry barrel type and meet requirements of UFC 3-600-01 and for aircraft hangars, UFC 4-211-01.

b. Sufficient clearance shall be provided for construction equipment to repair or replace utility lines in future.

c. Provide valves to isolate portions of utility lines to allow shut down for maintenance/repair without impacting neighboring facilities.

d. Reference IFS Section B02.3.1 for pavement cuts and underground utility line installation requirements.

e. Separation / depth requirements shall be IAW the International Plumbing Code or other referenced documents.

f. Depths of cover:

o 18 inches minimum for utilities within 5 ft. of building.

o 30 inches average for utilities in general unless an alternate depth is allowed/required per referenced documents or determined by detailed engineering.

14. Fire Suppression System:

a. Comply with separate Nellis-Creech IFS Fire Protection Requirements document and

UFC 3-600-01.

END OF MECHANICAL & PLUMBING REQUIREMENTS