Attachment 7 - LRAFB Mechanical Design Criteria.pdf

November 2018

General:

1. It is not the intent of these standards to inhibit design creativity. The intent is to introduce the designer to LRAFB standard design practices.

2. Sustainability

a. Designs shall comply with the latest edition of ASHRAE 90.1, ETL 94-04, AFP 32-1192 and UFC 3-400-01, 3-401-01, 3-410-01, 3-410-02, 3-420-01, 3-430-05, 3-600-01, and 3-600-02. Selected projects will be required to prove compliance with this standard via one of the recognized validation tools (COM-Check, BLAST, etc.). Details of this validation shall be discussed at the design charrette. The design-to building energy budget for renovation and new construction projects is to be in accordance with EO 13693. Electric resistance heating must not be used for heating or reheat except where permitted by UFC 3- 410-01.

b. MILCON projects are expected to meet minimum GBCI or USGBC certification criteria for sustainable design.

c. A life-cycle cost analysis is expected if there is no base requirement for a particular technology (ex: VAV vs. dedicated OSA systems, air-cooled package chiller vs. cooling tower). Such analysis is expected to be integral with the energy compliance in item (a) above. Results of that analysis, and resulting recommendations, are expected at the 35% design submittal.

d. Guidance on energy efficiency requirements for specific equipment (heat pumps, water heaters, etc.) are found at the Federal Energy Management Program website (http://www.eere.energy.gov/femp/technologies/eeproducts.cfm).

Federal law requires the Air Force to purchase equipment meeting these recommendations, as noted on the website.

e. All designs shall consider recycled material products. Products that utilize recycled materials shall be highlighted in the design analysis.

3. Security

a. All designs shall comply with UFC 4-010-01, DOD Anti-Terrorism/Force Protection Standards. These standards affect the placement of outside air ducts, emergency shutoff controls, and the location and condition of outdoor equipment.

Provide an emergency shutoff switch in the HVAC control system that can immediately shut down the air distribution and exhaust systems throughout the building and close all dampers leading to the outside.

b. Some Little Rock AFB projects require special security considerations, over and above those for anti-terrorism/force protection. The need for any such security provisions needs to be discussed at the design charrette. The following

19th Civil Engineer Squadron Mechanical Engineering Design

Criteria and Expectations documents contain detailed guidance for specific items that have affected HVAC systems in past projects. Additional project-specific documents and guidance may also be provided.

i. Director of Central Intelligence Directive (DCID) 6/9 Physical Security Standards for Sensitive Compartmented Information Facilities for all SCIF requirements. The acoustical standards are also employed for all areas that permit secure conversation. This can drive the need for duct silencers or other sound attenuation techniques.

ii. DOD 5200.1-R Information Security Program addresses vaults and secure rooms requiring open/closed storage or containing valuable items.

This can require non-passable duct sizes (<96 in2) or barriers to prevent covert entry.

iii. MIL-HDBK-1013-1/A Design Guidelines for Physical Security of Facilities provides details on ductwork barriers. Commercial products may or may not meet these standards.

4. All designs shall comply with the seismic restraint requirements of ETL 00-5 and US Army Corps of Engineers Technical Instructions 809-4 and 809-5.

5. All underground piping systems shall comply with the cathodic protection standards of UFC 3-570-06. The base puts a strong emphasis on the use of plastic pipe, where permitted by code, to obviate the need for sacrificial anodes or active cathodic protection.

6. All designs shall comply with the reliability and maintainability design checklist (ETL 01-01) and the Little Rock AFB constructability checklist.

Heating, Ventilating and Air Conditioning Systems

1. Load calculations shall use the following outside conditions, as defined for Little Rock AFB in the most recent ASHRAE Fundamentals Handbook.

a. Cooling: ASHRAE 1% dry bulb/mean wet bulb

b. Dehumidification: ASHRAE 1% dewpoint/mean dry bulb

c. Heating: ASHRAE 99% dry bulb.

d. Indoor setpoints:

i. Cooling: 75F at 50% relative humidity

ii. Heating: 72F

e. Ambient temperature 105 F (Cooling) & 0 F (Heating). The ambient conditions are for outside equipment only. Low ambient feature required for chillers and condensers, unless otherwise stated in statement of work.

2. All systems shall fully comply with the latest edition of ASHRAE 62, including all interpretations, addenda and errata (available for free on the ASHRAE website). All VAV system designs shall comply with the multiple-zone equation. The variable occupancy allowances can be applied to Little Rock AFB designs, so long as all criteria are met.

3. There is no smoking in Little Rock AFB facilities. Any provisions for smoking rooms or shelters will be addressed as project-specific items.

4. The base cannot accept use of Class I refrigerants. The base does not accept chillers containing refrigerant blends.

5. The project designer shall develop and provide a complete copy of the HVAC heating, cooling and ventilation loads analysis reports, as well as documentation of input conditions to the model (R-values, room sizes, etc.). The building envelope for new and previously un-conditioned space shall comply with ASHRAE 90.1. The analysis shall include written validation that the design complies with ASHRAE 62 and ASHRAE 55.

This information is typically provided with the 35% design submittal.

6. HVAC designs shall comply with all provisions of ETL 04-3, Design Criteria for Prevention of Mold in Air Force Facilities, which addresses the prevention of mold. The base has experienced some humidity control problems in both new and old buildings.

The usual culprits are either (1) quick sensible conditioning that doesn’t “wring out” the water vapor, (2) cycling of the cooling system, such that untreated outside air is sent to rooms, or (3) poor design/construction of the building envelope. It is imperative that rooms susceptible to these conditions be explicitly looked at, such as conference rooms, auditoriums, and large service bays with large doors but relatively low sensible heat loads. It is also imperative that the mechanical engineer works with the project architect in applying ETL 04-3, as many of its requirements apply to wall sections and the envelope. The preferred envelope/air barrier is at the roof with unvented attic. A good source of design instructions for humidity control is the ASHRAE Humidity Control Design Guide.

7. All refrigeration systems shall comply with ASHRAE Standard 15 – Safety Code for Mechanical Refrigeration.

8. Industrial ventilation designs shall comply with the latest edition of “Industrial Ventilation,” from the American Conference of Governmental Industrial Hygienists.

9. The following are technology options that the base prefers in projects. There may be instances where a specific project requires something different, but these apply 95% of the time

a. Airside

i. VAV with hot-water reheat

ii. Given the increasing requirements for outside air and the competing need to reduce energy use, the base is more interested in using dedicated outside air systems to separately treat outside air, rather than just mixing it with the return air. The benefits of using a dedicated OSA system shall be evaluated for each project . The use of demand control ventilation using VAV dedicated OSA units with space CO2 sensors shall be considered as well.

iii. Single-zone systems will only be considered on a limited basis. The Base requires the use of a centralized HVAC systems over multiple, small DX systems. A good use of single zones, that we’ve seen, is for rooms that have ventilation requirements that are atypical with surrounding spaces. Putting these on dedicated AHUs permits them to be properly ventilated without over-ventilating other areas.

iv. Residential systems shall not be used unless stated or approved otherwise., as most are not designed to continuously condition the required outside air flowrate, even when the inside sensible conditions are met.

b. Waterside: Provide a life cycle cost analysis for all three technologies listed below when the project size is large enough to support such technologies and provide the system that provides the best results.

i. Packaged, air cooled chillers will be equipped with low-ambient feature, unless otherwise stated in the statement of work..

ii. Cooling tower systems are NOT allowed on the base unless the project’s life cycle cost simple payback is less than 10 years. (Usually a 100 ton tower or greater when chemical and maintenance costs are considered). For such projects, the Little Rock AFB energy manager will be asked for direction. Any such towers will need consideration of materials, circulation fan exhaust path, basin cleaning, automatic bleed-and-feed system similar to Aquatrac part# 2032526 bleed/feed, timer for biocide feed, LMI Pump Part# 2026095 10 gpd/110 psi and chemical treatment to prevent mold, mildew, Legionnaire’s Disease, etc. Tower Tech, Inc. TTGE Series are preferred for 150 ton and above towers due to easy access of fan motors located on bottom of tower and plastic pan. Marley, Primus Towers with polyethylene basins, water distribution system, fan shroud and basin covers are preferred for towers below 150 tons.

iii. Ground-source heat pumps: The base has little practical experience with commercial GSHPs, but they are getting a lot attention within the federal government for energy-savings potential. Include GSHPs as candidates in the aforementioned life-cycle cost analyses, and construct them if they are the best candidate. Before considering analysis on this option, verify if ample site space would be available to support wells and determine sub-surface temperature, rock strength cover, weathered layer, rock thermal conductivity and diffusivity, water saturation and ground water flow. If site space is not available, this technology would not be required to be considered as a HVAC technology for the project.

c. Package units are OK in some conditions – consult with the base before committing to their use. Such units must comply with all of these requirements, including AT/FP provisions for OSA intake location. All exterior ducts shall be externally insulated ASHRAE 90.1 requirements and have metal protective covering.

d. Using multiple fan coil units scattered throughout a facility is discouraged, as their maintenance requirements are hard to meet with an ever-shrinking HVAC shop.

Consult with the base before committing to their use.

e. Energy recovery wheels are encouraged where funds and conditions permit. Total energy (enthalpy) wheels that are integral to the air handler shall be used in lieu of a plate type air-to-air heat exchanger. Wheel panels shall be individually removable to reduce replacement costs. Run-around loops can be offered as an alternative IF there are reasons not to use wheels, such as contaminated airstreams.

f. Multi-stage gas radiant heaters shall be used in all large, non-air conditioned spaces unless directed otherwise. Examples include hangers, vehicle repair areas, and large workshops.

g. All exterior HVAC units, condensers, etc. shall be factory finished “Satin Bronzetone” from Sherwin Williams ProMar Bronzetone Enamel Custom Colors, or “SW 2080 “Naturel” depending upon location. Coordinate with LRAFB Architect for correct color selection.

10. Specific Airside Requirements

a. In general, air handlers need to reflect the best qualities that manufacturers provide today, such as double walls with insulation, gasketed access panels, vibration-isolated fans, isolation valves on supply and return piping for coils, etc.

b. We do not want air handlers on roofs unless there is no alternative. The base will obviously relent if there is flat out no other choice, but there are almost always other choices.

c. Specs shall require that the contractor provide an extra set of filters and a spare fan belt(s) for each air handler and fan, in addition to whatever filters are consumed during commissioning.

d. All air handlers shall have their cooling coils in front of the heating coils, so that, if needed later, we can establish controls for re-heat. Systems without this arrangement are more expensive to establish humidity control, as extra equipment such as wheels are required for the reheat. Electric resistance heating must not be used for heating or reheat except where permitted by UFC 3-410-01.

e. Coils shall have dedicated isolation valves on supply and return lines, as well as unions, to facilitate coil pulls and control valve replacement.

f. Coil condensate lines shall be made of DWV copper tubing, with appropriate p-trap and vent. The line shall be run to the nearest floor drain (indirect connection). If a drain is unavailable, it can be run outside into an approved French drain or storm drain.

g. Unless otherwise required, all systems shall be equipped with MERV 8 (aka 30%) pleated air filters.

h. Ductwork shall comply with SMACNA ductwork construction standards. Ducts shall be galvanized sheet metal – ideally round but will accept square or rectangular where needed. Seal all supply, return and exhaust duct connections with mastic to meet SMACNA Class A. Flex duct will only be accepted for the purpose of placing diffusers and grilles in a suspended ceiling with a length not to exceed 3 feet with no turns. All supply, return and exhaust ductwork shall be externally insulated to ASHRAE 90.1 requirements. The base does not allow internal duct lining. All exterior HVAC ducts shall be painted “Satin Bronzetone” from Sherwin Williams ProMar Bronzetone Enamel Custom Colors, or “SW 2080 “Naturel” depending upon location. Coordinate with LRAFB Architect for correct color selection.

i. The use of duct sox shall be permitted in large open areas requiring heating and cooling. Duct sox may not be used with VAV systems unless the terminal dedicated to the duct sox run out maintains a constant flow or enough pressure to maintain the ducts’ shape.

j. All HVAC return shall be ducted – the base will not accept plenum or hallway return systems. We will not cry foul if this forces the use of return or relief fans in a design.

We’ve had many problems with air balancing and humidity control with such systems, and some of these arrangements no longer meet building and life safety codes.

k. All supply diffusers shall have insulation to prevent condensation. This shall be explicitly noted in either the specs or drawings.

l. Exhaust, relief and outside air intake openings shall be mounted either above the roof or high on sidewalls to meet AT/FP requirements. Spacing shall comply with the Arkansas Mechanical Code. Exterior surfaces shall be painted to a color selected by the base Contracting Officer – we have a lot of trouble getting this done if it is not explicitly noted in the drawings or specs.

m. Supply ducts shall have manual balancing valves, with extensions as needed to accommodate external insulation. The contractor shall not use diffuser dampers for balancing.

n. Unless specifically told otherwise in the project, all HVAC projects will include replacement of local exhaust fans in the affected areas (bathrooms, janitor’s closets, etc.). As most of these fans can influence airside balancing, building pressurization and air quality, their controls need to be coordinated with the rest of the HVAC system and explicitly documented in the control drawings.

o. Smoke and fire dampers shall be located per IBC requirements. A chart shall be provided on the drawings indicating what IBC paragraphs drive the use of these dampers.

p. Access doors shall be insulated and located at all operable internal ductwork items.

Access doors shall be of sufficient size to allow easy manual reset of smoke and fire dampers. Example, a 6”X6” opening in a 24” duct will be deemed unacceptable.

Where AT/FP provisions require security bar installation, access doors shall be located where personnel do not have to reach through security bars to access the smoke or fire damper.

11. Specific Waterside Requirements

a. Expansion tanks shall have flanged connections (similar to TACO CA tank) for ease of bladder removal and replacement.

b. All HVAC piping shall be covered with appropriate fiberglass, armaflex or foamglass insulation, with appropriate sheathing. Exterior, above grade water pipes shall have aluminum covers, with PVC covering over Armaflex acceptable for refrigerant lines.

c. Systems with exterior water pipes shall have a 30% propylene glycol mix, whether they are actually running in the winter or not. Draining is an acceptable alternative for cooling tower systems only if the unit does not need to run in the winter. The base will not accept ethylene glycol. Automatic glycol feeders are not required.

d. All package chillers shall have quick-connect fittings on supply and return to allow connection of a backup chiller. The connections are typically located outside, above-grade and near the chiller. Temporary Chiller Connections shall be aluminum cam and groove quick connect fitting. For chillers 50 tons and smaller provide and install a 2” Male NPT x Male Coupling with dust cap for both chilled water supply and chilled water return. (Equal to Dixon-Boss 200F-AL with 2DC.) For chillers larger than 50 tons, provide and install either a 4” or 6” connection depending on system flow requirements. The chilled water supply from the chiller shall be Female NPT x Male Coupling. The chilled water return to the chiller shall be Female NPT x Female Coupling. Each coupling shall be provided with an aluminum dust plug or dust cap respectively. (Equal to Dixon Boss 400A-AL or 600A-AL with 4DC or 6DC for Chilled water supply and Dixon-Boss 400D-AL or 600D-AL with 4DP or 6DP for Chilled water return.)

e. All air cooled chillers and cooling towers shall have HVAC air intake filter screens in lieu of hail guards or decorative air intake panels. Filters shall be field installed and equal to Arkansas Filter Inc., “Industrial” filter system with self-tapping stud adapter fastening system. (John Carrell 501-834-5837)

f. Provide 2nd through 5th year extended compressor warranty for all chillers.

g. The base prefers base-mounted, horizontal split-case centrifugal pumps. In-line pumps can be used if (1) they are located so as not to require more than 4’ AFF to service and replace, (2) not located behind any equipment that might cause difficulty to service and replace, (3) and their weight can be handled by one person.

h. The base prefers having primary and backup pumps for each water system. The base is receptive to using a Bell & Gossett recommended strategy for primary and backup pumps, which is to select each pump at ½ the flowrate but the total head, and to size the pipes for the total flowrate and head. At max loading both pumps will have to run, but if one fails, the single remaining pump is actually able to pick up most of the flowrate, since the pipes are now “oversized”. This, combined with the fact that most coils get 90% of their effectiveness with only 50% of the rated flow, allows this technique to (1) let system run on a single, reduced size pump most of the time, which significantly reduces energy use, and (2) provides full redundancy for the vast majority of the year. The only downside is that a logic controller to determine if one or two pumps are required, and 1 or 2 sensors.

i. All pumps shall be equipped with vibration isolators and a dP gauge.

j. All coils that are located outside shall be equipped with hail guards.

k. All coils and chillers shall be equipped with entering/exiting temperature gauges with English measurement scales, i.e. degrees Fahrenheit, psig, and a dP gauge.

l. Chillers shall have a flow switch that prevents their operation if the chilled water pumps are not on.

m. Each heated or chilled water system shall include a shot feeder equipped with an in-line filter assembly similar to Certified Labs (POC: Jim Lawrence 501-690-4389). A sight glass shall be included to permit water color comparison with manufacturer’s color charts.

n. RayPak MVB and Kewanee boilers are preferred as dictated by design loads, with failure isolation package capable of storing last 6 events and communicating with

EMCS.

o. The Base does not allow the use of butterfly valves for isolation purposes and shall not be used. Ball valves or gate valves are acceptable.

12. Controls

a. Unless specifically told otherwise, all new HVAC systems shall be connected to the base’s existing Trane Tracer Summit, via CE COINE connection, EMCS, and all construction contracts shall include the programming work and support needed to get all EMCS workstations to work with the new equipment. The EMCS must be able to display both graphical and tabular information on all HVAC equipment. The EMCS operator must be able to change set points and command equipment from the console. The Little Rock Trane Office can provide details on the nature of this connection. The base will not accept proposals that require alternative workstations for the EMCS operator. The Trane office also has some standard control and EMCS specifications for Little Rock AFB that permit competition while maintaining this user requirement.

b. Airside Economizer: ASHRAE 90.1 does not require Little Rock AFB to have ANY economizer. We have lots of complaints when airside economizers kick in on cool, damp days, and we’d prefer not to have them. Our concerns can be addressed by having separate dry-bulb temp and dewpoint sensors, both of which must indicate acceptable conditions.

c. Water-side economizers should be considered based on life cycle cost simple payback of 10 years or less, anytime the project has a year round cooling load and a cooling tower is selected for the project.

d. VAV shall be controlled with a “critical zone” reset strategy, which uses VAV damper position to determine the critical zone and corresponding fan speed. This has been found to save more energy than using a pressure sensor 2/3 the way down the longest duct. If leaving air temperature (LAT) reset is used during unoccupied periods, a dew point sensor must be used to override the reset. Dew point sensors are better than relative humidity sensors for controlling condensation and mold risk.

e. All VAV terminal unit controls shall be hardwired back to the unit controls and BCU.

This permits both the exchange of data/commands between the central unit and the terminal units, as well as exchange with the EMCS operator.

f. VAV terminal units shall be equipped with outlet air temperatures sensors. These are critical for remote, reliable troubleshooting.

g. VAV supply fan control shall be by VFD. We do not want inlet guide vanes, as they don’t save any energy.

h. Buildings shall be actively maintained at a positive pressure during summer months.

Positive pressure can be attained either with active controls on the return airflow (see next two paragraphs) or with different supply/return airflow rates for a given room.

i. The base prefers that buildings be at neutral or slightly negative pressure during winter months. This is to prevent the relatively moist inside air from being driven into the walls and establishing a condensation plane in the wrong place.

j. If a return fan is required, we request that it be equipped with a VFD that is controlled by a pressure sensor in the occupied space. This fan’s speed can be used to control the positive pressure in the facility. The base does NOT want the return fan to simply match the supply fan’s speed, as the fans usually have different performance curves. Speed matching often results in an unbalanced system.

k. All HVAC controls and EMCS wiring shall be in metal conduit – it’s OK to reference specific division 16 requirements for details on sizes, materials, etc. The junction boxes shall be labeled separately from those for other systems.

l. Control Contractor shall provide the Media Access Control (MAC) information to the Government (19 COMM) for IP address assignment.

13. Commissioning

a. For new HVAC systems, the contractor shall be responsible for developing and executing an HVAC commissioning plan per Corps of Engineers standard specifications section 230800.0010. Additional technical guidance on commissioning can be obtained from the Federal Energy Management Program website and ASHRAE Guideline 1.

b. All new or modified air and water-side systems shall be tested, adjusted and balanced, and a full report shall be provided in the O&M manuals. Report shall include copies of certification of the technicians and calibration of equipment.

c. All new ductwork shall be leak-tested per SMACNA, and this shall be explicitly noted in the specs, with the final leak report included in the O&M manuals.

d. All new or modified water-side system piping shall be flushed, cleaned, chemically cleaned, and propylene glycol added if required.

14. There shall be explicit details and/or sequences of operation for all unit heaters and small-scale HVAC systems. We’ve had several projects where a unit heater or ventilation fan detail was missing, and we had to mod the contract (with funds) to get any automatic controls.

15. Mechanical room ventilation shall include open/close dampers on mechanical louvers, unless the louvers are required for boiler/hot water heater air. Mechanical rooms shall have positive pressure ventilation (fan blowing into the room) to prevent natural gas exhaust from being sucked out of the flues and into the mechanical space.

16. Mechanical rooms often are shared with domestic water supply to the facility and fire protection risers. Mechanical rooms shall be provided with sufficient natural gas or HW unit heater to prevent freezing of these systems. This source shall be thermostatically controlled separate from any supply fan for the room(s).

17. WARRANTEE

a. The following equipment and systems will be provided to the Government with a minimum 2 year warrantee.

1. Direct Expansion Systems 10 tons or larger.

2. Package Systems 10 tons or larger.

3. Variable Frequency Drives.

4. Water Chillers.

b. All warranted systems and equipment utilizing refrigerant will be provided with a minimum 1 year refrigerant warrantee.

c. Warrantee period begins at project completion defined as C.E. Closeout.

The Contractor is responsible for acquiring components with a long enough warranty period to cover delivery, installation, testing, commissioning, and any work, mechanical or not, to project completion.

The Government will receive all warranted items with a full warrantee period.

Natural Gas:

1. All design and construction shall comply with the Arkansas Gas Code.

2. The following materials shall be used;

a. Below-grade: Plastic, in accordance with code.

b. Above-grade: Black Steel.

3. The base requires tracing wire and warning tape on all new underground plastic gas lines, and cathodic jumpers where new plastic pipe interrupts an existing metallic gas line.

4. All building service entrances shall be equipped with a gas meter, regardless of gas usage. This is to comply with UFC 3-400-01. Gas meters shall include a KYZ pulse-code output connected to an AMR transmitter to the base AMRS via CE COINE.

Provide manufacturer’s cut sheet on KYZ pulse coder. The gas meter shall be explicitly specified in the project specs, and its location identified on the drawings. Large gas meters shall be pad-mounted.

5. All exterior gas piping and specialties (regulator, meter, etc.) shall be painted to match adjacent building colors. The base prefers that the meter and regulator be positioned in an inconspicuous area. The regulator shall not be located near an outside air intake or operable window. Meters do not have to be by the roadside, and they do not need a bypass valve.

6. All valves, including below-grade, shall be metal – the shops have had poor results with plastic valves. Metal or plastic fittings, such as tees, are acceptable.

7. Equipment connections shall include stainless steel flex line and a dedicated stop.

8. The designer shall check with the base if it requires an automatic gas-cutoff valve tied to the fire alarm system. This is typically limited to large gas systems, such as in aircraft hangers, but needs to be explicitly determined for each project.

Plumbing:

1. All design and construction shall comply with the Arkansas Plumbing Code and the Americans with Disabilities Act (ADA).

2. The following materials shall be used;

a. Below grade supply: copper or PVC

b. Above-grade supply: copper

c. Above grade DWV: no-hub cast iron

d. Below-grade DWV: cast iron or PVC

The installation of PEX tubing is strictly prohibited.

3. Service Entrance

a. The water distribution system at LRAFB is privatized. Coordinate with Jacksonville Water Works for distribution line.

b. The need for water meters shall be governed by UFC 3-400-01. Selection and design shall comply with Army ETL 1110-3-465, Appendix A. All meters shall measure volume in gallons (not liters). Water meters may be located either in the mechanical room or in a concrete (not plastic) meter box, with the top at grade.

The meter shall be equipped with a KYZ pulse-code output connected to an AMR transmitter to the base AMRS via CE COINE. Provide manufacturer’s cut sheet on KYZ pulse coder.

c. The Base requires a RPZ backflow preventer in the domestic water service entrance. The BFP shall be located in the mechanical room, if at all possible.

The BFP shall be located 30” AFF for serviceability. If not, it shall be located above grade in a heated enclosure.

d. The service entrance shall enter the building in a mechanical room, not a janitor’s closet or other “user” room.

4. Supply Distribution

a. Makeup water supply to all HVAC systems shall include a RPZ backflow preventer. Each system; chilled water, heating water and when used cooling tower make up shall have independent RPZ’s and not be connected off a single unit.. Independent BFP required due to different chemicals utilized in the different systems. Cooling tower water make up will have paralleled RPZ to enable continued system operation during testing or repair actions. The BFP location shall comply with the Arkansas Plumbing Code for height above floor.

b. Each bathroom, kitchen, janitor’s closet, etc. shall have an isolation valve on all supply water lines running to it. This is to allow maintenance operations within that area without turning off water to the entire building.

c. The base prefers centralized, gas-fired hot water boiler with storage tank, but will consider instant-on systems for small projects if the conditions or economics warrant.

d. For centralized hot water heaters, the distribution system shall have a return loop and run-around pump w/thermostat control and an on/off switch for maintenance.

The base will consider deleting this requirement if the water heater and users are in proximity to each other, or if project costs dictate significant cuts.

e. Uurinal shall be hands-free, with a hard-wired power source (no batteries).

f. Water-coolers shall be surface mounted, dual deck water fountains. Semi-recess or recessed fountains are not allowed on LRAFB.

g. Water closets can be either floor or wall mounted. This shall be discussed with the Little Rock AFB architect early in design.

h. Showers shall be equipped with thermostatic mixing valves.

i. Exterior hose bibs shall be freeze-proof and shall include a vacuum breaker.

Each project needs to determine if these bibs need to be inside locked boxes, or can instead be the traditional residential type.

j. Provide a hose bib near the outdoor mechanical equipment to support coil cleaning and maintenance.

k. In accordance with DOD Memo “Water Use for Landscape Architecture on Department of Defense Installations/Sites”, potable water use is prohibited for irrigating new landscaping, other than for plant establishment.

l. Lawn irrigation systems shall have a separate water meter, with KYX pulse-code output to an AMR transmitter. The base prefers that the irrigation water supply branch off of the service entrance prior to the building’s water meter.

m. The base may want emergency shower/eyewash stations to be equipped with a flow switch that is connected to a central buzzer/light panel located elsewhere in the facility. This is typically limited to areas where folks may not be able to get immediate assistance, such as aircraft hangers. This needs to be discussed with the user and base fire department early in design. An alternative to the local panel is to attach the switches to the fire alarm system, with dedicated zone ID.

Refer to UFC 3-420-01 Appendix D.

n. All temporary connections shall be made via a RPZ backflow preventer.

o. The Base does not allow the use of butterfly valves for isolation purposes and shall not be used. Ball valves or gate valves are acceptable.

5. Drain, Waste and Vent Lines

a. The base wants to minimize the number of floor drains in industrial areas, due to concerns with illegal dumping. This includes drains that are traditionally included with eyewash stations. A project-specific evaluation will be required to determine if the drain is required, or if alternatives exist (ex: test buckets w/socks).

b. The base prefers to minimize cleanout locations in areas subject to high people traffic or high visibility. Cleanout locations shall provide sufficient space for maintenance personnel and equipment.

c. Removable P-traps shall not be used as a substitute for cleanouts.

d. A double cleanout shall be located just outside the building on each sanitary main leaving the building.

e. All external cleanouts shall have a min of a 12”x 12”x 4” thick concrete collar (per cleanout) poured around them for protection.

f. Where exposed, ADA lavatory drain lines shall be wrapped in a pre-manufactured insulation product that is either noted in the drawings or identified in the specs. We have had contractors create horrible-looking duct tape and armaflex pads in the past, and we need specs or drawing notes to stop that.

Fire Suppression:

1. All fire suppression systems shall comply with UFC 3-600-01, the Arkansas State Fire Code, and applicable NFPA standards. There are several additional military standards for specific facilities, including;

a. ETL 98-08: Fire Protection for Existing Aircraft Facilities

b. UFC 4-211-01 Fire Protection for New Aircraft Facilities

c. ETL 01-18: Fire Protection for Electronic Equipment Installations

2. Fire protections designs shall be accomplished by a registered Fire Protection Engineer as referenced in UFC 3-600-1. All designs shall be a full completed design to include hydraulic calculations and performance design/specification are not allowed by LRAFB.

3. Preferred materials:

a. Below-grade: AWWA C-900 PVC pipe with iron fittings and building stub-in.

b. Above-grade: Black steel; grooved 2.5” diameter and larger, and threaded 2” diameter and smaller. Thread-o-lets are often used on base projects for connecting the small lines to the distribution lines.

4. Fire department connections shall be siamese (2.5”x 2.5”x 4”), and its location shall be coordinated with the base fire department. Ideal locations are close to fire hydrants and roads with multiple entrances/exits. The FDC may on the building wall or at some distance away on a standpipe, depending on project conditions.

5. The base prefers post-mounted indicator valves for service entrances, rather than wall-mounted. NFPA 13 (2007) provides PIV locations in section 8.16.1.3, they are listed in suggested order of preference but LRAFB requires them in the order of preference and if a Contractor cannot meet the requirements, the contractor is required to provide justifications on why they cannot meet the requirements. LRAFB will provide a response to the Contractor’s justifications.

6. Outside equipment shall be painted, with color selected by the Contracting Officer.

Usually they are painted a dark brown.

7. A double-check backflow preventer that meets the above codes is required at the service entrance including any by-pass lines. The double check backflow preventer shall not be a detector type assembly. “Silver Bullet” type backflow preventers are not acceptable to

LRAFB.

8. The base does not require a water meter on the fire suppression service entrance.

9. The base strongly prefers alarm valves to simple flow or pressure switches to trigger the fire alarm system. We’ve had some sensors tricked by pressure waves in the system, and sometimes the adjustable delay timers don’t resolve the false alarm problem.

10. The base prefers mechanical water gongs to those driven by the fire alarm system. The fire department’s first responder crew has higher confidence that the event is real if a mechanical device, independent of the smoke/heat/flame detectors, is in alarm.

11. The designer or contractor shall see base input on zoning the fire suppression system.

We prefer large buildings to have zoned suppression systems to (1) provide more detailed location data to the fire department when heads are activated, and (2) allow for partial shutdown for maintenance, rather than isolating the entire system. Zones shall be equipped with their own drain lines and tamper switches.

12. Sprinkler heads shall be centered in ceiling tiles – this need to be explicitly noted in the specs and drawings.

13. Flexhead sprinklers are acceptable to LRAFB for use in fire suppression system. They need to be accounted for in the hydraulic calculations.

14. Design drawings need to indicate locations for the following items:

a. Service entrance and post indicator valve (PIV).

b. Test line locations (Inspectors test station discharge shall be piped to the outside and NOT to a floor drain or sink). Splash blocks are required at discharge point.

c. Drain locations (Main drain shall be piped to the outside and NOT to a floor drain or sink). Splash blocks are required at discharge point.

d. Fire department connection

e. Fire hydrant

15. For each project, the designer or contractor shall inquire with the base on the style of head. We have recently started requesting semi-recessed pendants in office space as a good compromise on price and aesthetics. They are either chrome head/escutcheon or a color that matches adjacent surfaces. We will sometimes request concealed heads in areas where there is concern of inadvertent damage to the heads (such as in high-value computer rooms).

16. Heads in mechanical/electrical/comm rooms shall have protective guards.

17. Additions to existing sprinklers systems shall include re-calculation of the hydraulic design.

18. The fire suppression system shall not utilize gate valves.

19. HIGH EXPANSION FOAM SYSTEM TESTING PLAN

a. All testing will be performed in accordance with UFC 4-211-01.