Solicitation Attachment 7 - Basis of Design - Design Narrative.pdf

Basis of Design

Part II: Design Narrative Replace HVAC Base Wide Charlotte North Carolina Air National Guard – 145th Airlift Wing

Type B-3 Submittal – Final Design

Charlotte, North Carolina March 2020

National Guard Bureau Contract W9133L-15-D-0004 Task Order W91242-18-F-0127 Project Number FJRP142610 https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwi4pfuVvLPeAhUkzoMKHf0JDRYQjRx6BAgBEAU&url=https://en.wikipedia.org/wiki/Air_National_Guard&psig=AOvVaw1e7yx33ETEV0Am829IvgMZ&ust=1541171166529076

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NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative Contents i

1 Introduction

1.1 Project Background

1.2 Project Scope

1.3 Project Phasing

2 Building Design Narrative

2.1 Overall Design Narrative

2.2 Building 2

2.3 Building 39

2.4 Building 45

2.5 Building 49

2.6 Building 50

2.7 Building 58

2.8 Building 61

2.9 Building 62

2.10 Building 63

2.11 Building 65

2.12 Building 67

2.13 Building 69

2.14 Building 72

NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative ii

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NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative Introduction

1 Introduction This design analysis supports the development of a conceptual design to provide repair and upgrades to the HVAC systems base wide with the primary goal to eliminate all of the aging non-compliant R-22 refrigerant systems and install necessary smart meters on designated facilities in accordance with Air National Guard (ANG) guidance. It is further intended to demonstrate an understanding of the project concept and to provide information for estimating the cost of the project. This report was prepared by HDR Engineering, Inc. (HDR) for the North Carolina Air National Guard 145th Airlift Wing (AW), under contract W9133L-15-D-0004, Task Order W91242-18-F-0127.

1.1 Project Background

Charlotte Air National Guard Base (ANGB) is a military base located by the Charlotte Douglas International Airport in North Carolina and is home of the 145th AW. The 145th AW unit is converting to the C-17 aircraft in support of operations in the United States and overseas, fulfilling a wide range of operational missions in both peach and war situations.

The 145th AW requires facilities that are adequately sized, configured, and conditioned to support the functions in various facilities that provide direct and indirect support to the missions.

The air-conditioning and chiller systems are required to be energy efficient and maintainable to provide the proper environment to meet the various mission needs. The ANG is required to comply or exceed all environmental mandates associated with the phase out of hydro chlorofluorocarbon (HCFC). A fully operational smart meter monitoring system is required by 2020 to meet Department of Defense (DoD) guidance. The remaining air conditioners have either been upgraded or are programmed to be upgraded as part of another facility specific upgrade project. Programmed local sustainment, restoration, and modernization funding needed to repair these systems is insufficient.

1.2 Project Scope

This project requires the replacement of all existing R-22 HVAC equipment base wide.

Replacement systems shall be designed to meet or exceed UFC1-200-02 High Performance and Sustainable Building Requirements, dated December 2016, which requires the optimization of energy efficiency and the use of ASRAE 90.1 (2013) minimum criteria. Where feasible these minimum requirements should be exceeded to take advantage of higher seasonal energy efficiency ratio (SEER) and energy efficiency ratio (EER) equipment.

Equipment to be replaced includes an air cooled chiller, split systems (heat pumps and furnaces), as well as package roof top units RTUs). Unit sizes vary from 1.5 tons to 20 tons, with the chiller having a capacity of 70-tons. In the case where the condensing unit or heat pump is to be replaced as part of the split system, the matching air handler/furnace will be replaced as well. The existing cooling coils were originally designed for R-22 refrigerant, which has different design pressure and properties than the new R-410 refrigerant that will be installed. In order for the system to operate at the high efficiency as designed, the air side equipment (which houses the cooling coil) requires replacement as well.

NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative Building Design Narrative

The existing smart meters and reporting system shall be expanded to include the eleven electrical and natural gas smart meters for the designated buildings at Charlotte ANGB. Smart meters are needed to meet a Presidential mandate to provide Energy Dash Board monitoring for utilities NGB wide. Where no meters exist in a facility a Building Automation System (BAS) controller shall be designed into the facility. Basis of design is Alerton and must be integrated to the existing Alerton graphics and energy dashboard system.

1.3 Project Phasing

The existing site and facilities will be occupied during construction of the planned work.

Contractor shall determine phasing requirements as it relates to maintaining building operations, coordination with facility personnel, and protection of stored material. An estimated construction schedule is included with this submittal. Coordination between the contractor and Government is required for this work.

2 Building Design Narrative The design intent for the project is to replace all of the aging, non-compliant R-22 refrigerant systems and install necessary smart meters on designated facilities that is compatible with current Air National Guard Engineering Technical Letters (ANGETLs), Unified Facilities Criteria (UFC), codes, DoD and Air Force standards.

2.1 Overall Design Narrative

2.1.1 Architectural

The new mechanical work may require new plumbing and refrigerant lines to penetrate exterior walls. These penetrations will typically be 2 inches in diameter or less and will be provided by core drilling through the exterior wall assembly. Fire stopping caulk/sealant will be provided around the perimeter of each pipe penetration.

Any existing roof penetrations and ground mounted concrete slabs shall be reused. Any damages to existing systems shall be repaired to match existing. If any new roof penetrations are required, the Government/COR shall be notified regarding the existing roof warranty.

2.1.2 Mechanical

All heating, ventilation, air conditioning, and plumbing will be designed in accordance with the 2015 International Building Codes (IBC), UFC Series, and ANG design standards.

Mechanical systems will be designed in accordance with ANGETLs, Technical Orders (TOs) and other applicable documents. This shall include applicable codes, industry standards and practical engineering methods. The mechanical design is based on the following criteria:

• Performance factors that include efficiency, simplicity, durability, and functionality.

• Cost factors that include first costs, long-term operational costs, and maintenance costs.

• Design factors that influence and benefit acquisition of points towards desired

Leadership in Energy and Environmental Design (LEED) points.

NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative

High-quality, energy efficient equipment will be selected with life-cycle costs in mind. Control systems will be designed to provide the required functionality, system control and monitoring, and will maximize energy conservation within operational constraints. Current base standard for HVAC controls to be matched is Alerton.

2.1.3 Electrical

For buildings that require an HVAC replacement, existing equipment will be replaced with a new, high-efficiency equivalent during this project. Since the new unit’s electrical requirements will match the existing equipment electrical requirements, the new equipment will be wired to the existing circuit breaker that previously served the existing equipment. Note that the power design requirements, and the connection requirements for the new equipment shall be coordinated with applicable codes such as: the National Electrical Code (NEC), applicable UFC requirements, the local authority having jurisdiction (AHJ), applicable National Fire and Protection Association (NFPA) codes, and applicable UL standards. In instances where the system, its boxes, and/or disconnects, etc. are located outdoors, the equipment to be provided will be NEMA 4X rated. Where the equipment, its boxes, and/or disconnects, etc. are located indoors in non-hazardous areas, the equipment to be provided will be NEMA 1 rated. All electrical wiring will be copper with THWN/THHN insulation, and will be routed in rigid conduit (to include electrical metallic tubing, rigid galvanized steel, and flexible steel, water tight), unless conditions dictate otherwise. Conduits located within hazardous areas, and up to 50 feet outside of the hazardous area, will have seal fittings to minimize the passage of gases to and from electrical equipment. Exposed conduits routed in wet, corrosive, and hazardous areas will be PVC coated rigid galvanized steel. Conduits routed underground shall be rigid PVC.

Smart metering (electric and natural gas) will be provided to meet the Presidential mandate to provide Energy Dash Board monitoring for utilities. The design and selection of these meters will be coordinated with the COR to ensure that the meters selected meet the current UFC and Air Force Requirement. Meters shall be compatible with the existing system.

2.2 Building 2

Building 2 is the William J. Payne headquarters building. It is a single-story brick building with a metal roof. Building 2 is approximately 24,132 SF and consists of predominantly administrative office and conference room space.

2.2.1 Existing HVAC Design and Systems

Building 2 is conditioned by various types of HVAC systems. Each system serves a different portion of the building which is separated into three sections referred to as: the main office area, the east wing, and the west wing. All equipment, including the air handlers, terminal boxes, and boiler, are tied into an existing building management system.

The main office area spans the entire length of the building and is conditioned by AHU-2 that serves a series of terminal boxes with electric reheat located throughout the space. AHU-2 is a variable volume central station air handler with a hot water heating coil and a multi-circuit direct expansion (DX) coiling coil that was installed in 1998. Heating hot water is provided by a gas-fired, 600 MBH Lochinvar boiler (Model: KBN601) that was installed in 2014-2015. Cooling

NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative capacity is provided by two 20 ton Trane air cooled condensing units. One unit, CU-2B (Model:

TTA240B300FA), was installed in 2007-2008 and the other, CU-2A (Model: TTA240E300AA), in 2011-2012. CU-2B is currently an R-22 machine, but it and AHU-2 are being replaced as part of the base wide HVAC replacement project.

The east wing offices are conditioned by a Daikin variable volume (VFD on supply fan), central station air handler (AHU-1) with a hot water heating coil and a DX cooling coil. AHU-1 serves a series of terminal boxes with electric reheat and was installed in 2014. Heating hot water is provided by the Lochinvar boiler and the cooling capacity is provided by a 15-ton, Trane air cooled condensing unit (Model: TTA180F300AA) that was installed in 2013-2014.

The west wing offices are conditioned by a Trane variable volume central station air handler, AHU-3 that was installed in 1998. AHU-3 serves terminal boxes with electric reheat that are located throughout the office space. AHU-3 has a DX cooling coil and an inline, gas-fired, duct mounted heater for heating capacity. Cooling capacity is provided by a 20-ton York air cooled condensing unit (CU-3) that was installed in 2005-2006. CU-3 and AHU-3 is also an R-22 system that is being replaced as part of the base wide HVAC replacement project.

2.2.2 HVAC Design Work

There are no known code issues with the equipment or the current operation of the HVAC equipment in Building 2. There is also no issue with HVAC system capacities or existing building controls. Overall, after the replacement of the R-22 equipment and their associated air handlers, and the zone dampers, the system as a whole will almost be completely new.

On the distribution side, the zone and bypass dampers are approximately 20 years old and are in need of replacement. Building maintenance staff requested new terminal boxes to be complete with hot water coils for reheat. See below for a list of work to be completed.

• Prior to construction and after the installation of the new heat pump units (02HP-2A, 02HP-2B, and 02HP-03) and air handlers (AHU-2 and AHU-3) perform a building wide test and air balance (TAB) analysis. This report will identify potential air flow issues, setpoint control, and fan control issues for the entire building. This evaluation would be helpful in discovering potential issues/leaks with the duct system as well.

• Perform a complete duct cleaning and inspection. All supply ductwork (at a minimum) shall be installed with minimum 1” thick insulation.

• Confirm that the existing building automation system (BAS) controller was linked to new HVAC equipment. This allows base maintenance personnel to diagnose operating issues and set building temperature set points.

• Replace all thirty-nine existing zone/bypass dampers and provide new terminal boxes with hot water coils for reheat. Perform building heating load calculations to determine that existing boiler capacity is sufficient. Provide all new terminal boxes with 3-way valves. Currently there is no heating hot water distribution throughout the building.

• Identify areas where multiple spaces are controlled by the same zone damper and provide with a new terminal box; this will create a new zone. It is recommended to

NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative rezone the building based on past floor plan changes to improve controllability and occupant comfort.

• Replace refrigerant lines associated with ACU-1, ACU-2A, and ACU-2B..

Confirm that all temperature sensors within the building are installed in the appropriate locations. Ideal location would be next to the entry way of offices and/or next to return air grilles.

If multiple areas are conditioned by the same box, locate the temperature sensor in the area that is more critical to maintain space comfort. It is not recommended for sensors to be installed near exterior walls, in areas of direct sun exposure, directly under a supply diffuser, or behind any equipment or furniture.

2.3 Building 39

Building 39 is the Petroleum, Oils, & Lubricants (POL) Operations facility. It is a single-story brick building with a metal roof. Building 39 is approximately 1,333 SF and consists of predominantly administrative office and class room space.

2.3.1 HVAC Design Work

The only HVAC work in this facility is to provide a new BACnet router, temperature sensor and thermostat VLC/D. New building router shall be connected to the main controller (Model:

BCM/E) located in Building 63.

2.3.2 Electrical Design

Work in this building will consist of installing and connecting an electrical SMART meter to provide metering information to the Charlotte ANGB. The design and selection of these meters will be coordinated with the COR to ensure that the meters selected meet the current UFC and Air Force Requirement. Meters shall be compatible with the existing system.

2.4 Building 45

Building 45 is the Composite Support building. It is a two-story brick building with a flat roof.

Building 45 is approximately 29,004 SF and consists of a combination of administrative offices, medical offices, computer/information technology (IT) spaces, and a large dining area on the first floor.

2.4.1 Existing HVAC Design and Systems

Building 45 is conditioned by a local hydronic system. The building resembles a “U” shape and each side of the building is served by one of two central station air handlers located in mechanical rooms on the second floor. There is a large mechanical room located in the northwest corner of the first floor where the boiler, pumps, and make-up air unit are located. All equipment including the boiler, chiller, air handlers, pumps, and terminal boxes are tied into an existing building management system.

2.4.1.1 COOLING SYSTEM

Cooling capacity for the building is generated by a ground mounted, 70-ton air-cooled chiller.

The chiller, an R-22 machine, is scheduled to be replaced as part of the building wide HVAC replacement project. Chiller provides cooling water to two main central station air handlers via two 5-HP circulation pumps. One pump is 100 percent redundant. Conditioned air is delivered to

NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative a combination of terminal boxes located throughout the space. AH-1, located in the west mechanical room, is scheduled at approximately 15,000 cfm and AHU-2 delivers approximately 4,000 cfm. Each of these air handlers serves both floors of their wings of the building respectively.

There are a combination of Liebert DX split systems that serve computer room and IT spaces.

All condensing units for these systems are mounted on the roof. Each of these systems are already scheduled to be replaced as well.

2.4.1.2 HEATING SYSTEM

There is a large, 2.08 MMBH, gas-fired, Weil-McLain boiler that provides heating hot water to the central air handlers and reheat coils located in the building. The boiler was installed in 1983 and has nameplate heating efficiency of 81 percent. Hot water is circulated through the building by two 20 HP circulation pumps. One pump is 100 percent redundant. There is also a large make-up air unit that serves the kitchen and dining spaces that only has a heating coil.

2.4.2 HVAC Design Work

In general, after the scheduled replacement of the air cooled chiller, the cooling system and the central station air handlers are in good working condition.

The heating system is showing signs of age and as a whole requires regular maintenance.

• After the installation of the new air cooled chiller and split system computer room units, perform a building wide TAB analysis. This report will identify potential air flow issues, setpoint control, and fan control issues for the entire building. This evaluation would be helpful in discovering potential issues/leaks with the duct system as well.

• Perform a complete duct cleaning and inspection. All supply ductwork (at a minimum) shall be installed with minimum 1-inch thick insulation.

• Provide and Install new BAS controller and link to new and existing HVAC equipment.

This allows base maintenance personnel to diagnose operating issues and set building temperature set points.

• Replace existing boiler and provide with new, high efficiency condensing boiler. Perform heating and cooling loads based on current building occupancies and room types to confirm adequate heating capacity is provided.

• Replace distribution pumps (hot water and chilled water) as they are approaching the end of their useful service life. Hot water pumps (P-3 and P-4) are approximately 15 years old.

Confirm that all temperature sensors within the building are installed in the appropriate locations. Ideal location would be next to the entry way of offices and/or next to return air grilles.

If multiple areas are conditioned by the same box, locate the temperature sensor in the area that is more critical to maintain space comfort. It is not recommended for sensors to be installed near exterior walls, in areas of direct sun exposure, directly under a supply diffuser, or behind any equipment or furniture.

NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative

2.5 Building 49

Building 49 is a small 2,520 SF HAZMAT facility. It is a single story building with a combination of block and brick wall construction with a flat roof.

2.5.1 Existing HVAC Design and Systems

Building 49 is currently ventilated and only a small office of the building is conditioned.

Conditioned air is delivered by a single, 2-ton packaged RTU (R-22 machine) controlled by a wall mounted programmable thermostat.

2.5.2 HVAC Design Work

The packaged RTU is scheduled to be replaced as a part of the base wide HVAC replacement project. There are no recommended upgrades to Building 49.

A new BACnet router, temperature sensor, and door switches will be installed. New building router shall be connected to the main controller (Model: BCM/E) located in Building 63.

2.6 Building 50

Building 50 is the Group Training facility. It is a single-story brick building with a metal roof.

Building 50 is approximately 5,030 SF and consists of predominantly administrative office and multi-purpose space.

2.6.1 HVAC Design Work

The only HVAC work in this facility is to provide a new BACnet router, temperature sensor, thermostat VLC/D, and door switches. New building router shall be connected to the main controller (Model: BCM/E) located in Building 63.

2.6.2 Electrical Design

Work in this building will consist of installing and connecting an electrical and natural gas SMART meter to provide metering information to the Charlotte ANGB. The design and selection of these meters will be coordinated with the COR to ensure that the meters selected meet the current UFC and Air Force Requirement. Meters shall be compatible with the existing system.

2.7 Building 58

Building 58 is the Base Mobility Storage warehouse. It is a single-story metal building with a metal roof. Building 58 is approximately 6,635 SF and consists of 10 bays in the warehouse.

2.7.1 HVAC Design Work

The only HVAC work in this facility is to provide a new BACnet router, temperature sensor, and thermostat VLC/D. New building router shall be connected to the main controller (Model:

BCM/E) located in building 63.

2.7.2 Electrical Design

Work in this building will consist of installing and connecting an electrical and natural gas SMART meter to provide metering information to the Charlotte ANGB. The design and selection of these meters will be coordinated with the COR to ensure that the meters selected meet the current UFC and Air Force Requirement. Meters shall be compatible with the existing system.

NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative

2.8 Building 61

Building 61 is the Aeromedical Evacuation Squadron facility, with a total building area of 14,524 SF. The facility is a two story brick building with a flat roof. Currently, there is a funded project to replace the roof which is expected to be completed in 2019.

2.8.1 Existing HVAC Design and Systems

Building 61 is conditioned by a total of seven gas packaged RTUs; all are constant volume and are controlled by a wall mounted thermostat. They range in size from 2 tons to 8 tons and all were installed in 1996-1997.

Each RTU is currently zoned out to serve a different part of the building. As designed, RTU-2 and RTU-7 are ducted down through a provided chase to serve the first floor class room and supply office areas. The other units all serve the second floor. All units are controlled by a single space temperature sensor.

2.8.2 HVAC Design Work

All seven of the gas packaged RTUs are already scheduled to be replaced in the base wide HVAC replacement project. This will provide all new HVAC equipment for this building with the exception of some small exhaust fans. There is no issue with the HVAC system capacities, zoning, or existing building controls.

• Currently there are no regulators installed on the natural gas supply piping to the RTUs.

Confirm they are installed, or integral to the unit, at time of replacement.

• Replace all gas distribution piping on the roof (approx. 200 LF). Piping has become rusted and bent in some areas. Confirm existing pipe routing and size is adequate for new roof mounted equipment and their heating capacities.

• After the installation of the new RTUs, perform a building wide TAB analysis. This report will identify potential air flow issues, setpoint control, and fan control issues for the entire building. This evaluation would be helpful in discovering potential issues/leaks with the duct system as well.

• Confirm that existing BAS controller was installed and linked to new HVAC equipment.

This allows base maintenance personnel to diagnose operating issues and set building temperature set points.

• Perform a complete duct cleaning and inspection. All supply ductwork (at a minimum) shall be installed with minimum 1-inch thick insulation.

2.9 Building 62

Building 62 is the Visual Information building. It is a single-story brick building with a metal roof.

Building 62 is approximately 2,050 SF and consists of predominantly administrative office and multi-purpose space.

2.9.1 HVAC Design Work

There will be no HVAC work performed at this building.

NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative

2.9.2 Electrical Design

Work in this building will consist of installing and connecting an electrical and natural gas SMART meter to provide metering information to the Charlotte ANGB. The design and selection of these meters will be coordinated with the COR to ensure that the meters selected meet the current UFC and Air Force Requirement. Meters shall be compatible with the existing system.

2.10 Building 63

Building 63 is the Base Supply warehouse that consists of a total building area of 39,534 SF.

The facility is separated into two different types of spaces: a warehouse and some administrative offices. It is single story block and brick building with an interior mezzanine above the office space. The roof is slightly barreled and has skylights to allow natural light into the warehouse space.

2.10.1 Existing HVAC Design and Systems

The warehouse area is only heated by a number of natural gas fired, radiant tube heaters. Each heater has a local thermostat.

The office and administrative areas are conditioned by a series of split systems with gas furnaces. There are a total of six split systems ranging from 2.5 to 4 tons. The only roof mounted equipment are two exhaust fans that work to provide ventilation for the warehouse area.

All radiant heaters in the warehouse space, along with their associated controls, are in good working condition.

Currently, there are four condensing units located under a covered storage area along the east wall of the warehouse and the other two are located just outside of a mechanical room in the south east corner of the building. Two of the four units under covered storage (3 and 3.5-ton systems) and the other two (2.5 and 4-ton systems) located outside of the mechanical room are scheduled to be replaced as part of the base wide HVAC replacement project.

2.10.2 HVAC Design Work

In general, there are no known code issues with the equipment or the current operation of the HVAC equipment in Building 63. There is also no issue with HVAC system capacities or existing building controls. Overall, after the replacement of the R-22 equipment and their associated furnaces, the heating and cooling equipment in general are in good working condition and are still in the early years of its expected service life. See below for new work to be completed:

• After the installation of the new split systems, perform a building wide TAB analysis. This report will identify potential air flow issues, setpoint control, and fan control issues for the entire building. This evaluation would be helpful in discovering potential issues/leaks with the duct system as well as overall fan operation to see if supply air to space matches with the design airflow as intended.

• Perform a complete duct cleaning and inspection. All supply ductwork (at a minimum) shall be installed with minimum 1-inch thick insulation.

NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative

• Confirm that existing BAS controller was installed and linked to new HVAC equipment.

This allows base maintenance personnel to diagnose operating issues and set building temperature set points.

• Relocate existing condensing units such that they are closer to their matching indoor unit. Refrigerant line lengths that exceed the manufacturers recommendations may not function properly and can reduce the cooling capacity of the unit. The working pressure of the refrigerant is not enough to overcome the distance of the run and can cause issues with the compressor’s operation. Condensing units will be relocated to the roof above the mezzanine level.

2.11 Building 65

Building 65 is the Aircraft Support Equipment (ASE) Maintenance building. It is a single-story brick building with a metal roof. Building 65 is approximately 5,215 SF and consists of predominantly open storage warehouse space.

2.11.1 HVAC Design Work

There will be no HVAC work performed at this building.

2.11.2 Electrical Design

Work in this building will consist of installing and connecting an electrical and natural gas SMART meter to provide metering information to the Charlotte ANGB. The design and selection of these meters will be coordinated with the COR to ensure that the meters selected meet the current UFC and Air Force Requirement. Meters shall be compatible with the existing system.

2.12 Building 67

Building 67 is the Vehicle Maintenance OPS facility with a total building area of 14,044 SF. The facility is separated into two main sections: an office and administrative area and a vehicle maintenance bay. The building is made up of block and brick construction and has a sloped roof. There are a total of five roll-up doors to access the maintenance bay.

2.12.1 Existing HVAC Design and Systems

The maintenance bay portion of the warehouse is heated and ventilated only.

The office and administrative portion of the facility is conditioned by a combination of three split systems with gas furnaces and a 1.5-ton split system heat pump. The other systems consist of two 4-ton units and a 5-ton unit. All outdoor units are installed directly outside of the mechanical room on the south side of the building. All refrigerant lines are routed down below the concrete slab/drive aisle and enter the building in the small work area located in the warehouse space.

From there, three of the refrigerant line sets are routed to the adjacent mechanical room where the furnaces are located. The air handler associated with the heat pump is located high on the wall in the same work area.

All furnaces and the air handler in Building 67 are constant volume units. Additionally, all are controlled by a wall mounted thermostat. The building was initially designed to meet the heating and cooling loads of the building on a drill weekend while normal operation only has about 20

NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative percent of the active personnel. All four of the existing split systems are scheduled to be replaced as part of the base wide HVAC replacement project.

2.12.2 HVAC Design Work

There are no known code issues with the equipment or the current operation of the HVAC equipment in Building 67. In general, after the scheduled replacement of the split systems and the addition of new Alerton controls, all HVAC equipment will be new.

• After the installation of the new split systems, perform a building wide TAB analysis. This report will identify potential air flow issues, setpoint control, and fan control issues for the entire building. This evaluation would be helpful in discovering potential issues/leaks with the duct system as well.

• Perform a complete duct cleaning and inspection. All supply ductwork (at a minimum) shall be installed with minimum 1-inch thick insulation.

• Provide and Install new BAS controller and link to new and existing HVAC equipment.

This allows base maintenance personnel to diagnose operating issues and set building temperature set points.

Confirm that all temperature sensors within the building are installed in the appropriate locations. Ideal location would be next to the entry way of offices and/or next to return air grilles.

If multiple areas are conditioned by the same box, locate the temperature sensor in the area that is more critical to maintain space comfort. It is not recommended for sensors to be installed near exterior walls, in areas of direct sun exposure, directly under a supply diffuser, or behind any equipment or furniture.

2.13 Building 69

Building 69 is the CES Recruiting and Fitness Center facility. It is a single story, 8,037 SF building. The building is divided into two different sections: a smaller office/administrative area and a larger fitness space. The south facing side consists of large expansive windows that appear to have replaced roll-up doors sometime in the past.

2.13.1 Existing HVAC Design and Systems

Building 69 is currently conditioned by a series of split system heat pump units. There is a large 10-ton split system and a 4-ton system that serves the fitness areas. Two 3-ton split systems are responsible for conditioning the recruiting and administrative area.

Building 69 is zoned properly which allows each system to function independently of each other.

Building maintenance personnel indicated that there were no issues with the HVAC systems or the building controls in this building.

2.13.2 HVAC Design Work

With the exception of one of the 3-ton systems that serves the administrative areas, the other systems have been recently replaced and are in good operating condition. The single, Trane 3-ton split system heat pump is an older R-22 system that has already been scheduled to be replaced as a part of the base wide HVAC replacement project.

NC ANG 145th Airlift Wing | Replace HVAC Base Wide Charlotte – Basis of Design Part II: Design Narrative

• Provide and Install new BAS controller and link to new and existing HVAC equipment.

This allows base maintenance personnel to diagnose operating issues and set building temperature set points.

2.13.3 Electrical Design

Work for this building will consist of installing and connecting an electrical and natural gas SMART meter to provide metering information to the Charlotte ANGB. The design and selection of these meters will be coordinated with the COR to ensure that the meters selected meet the current UFC and Air Force Requirement. Meters shall be compatible with the existing system.

2.14 Building 72

Building 72 is the Information Technology Network (ITN) Shelter facility. It is a single-story brick building with a metal roof. Building 72 is approximately 360 SF and consists of one open room used for servers and communications equipment.

2.14.1 Existing HVAC Design and Systems

Building 72 is currently conditioned by two vertical terminal air conditioning units. One is installed at each end of the building. They are both 2-ton units and are being replaced as part of the base wide HVAC replacement project.

Building 72 is zoned properly which allows each system to function independently of each other.

Building maintenance personnel indicated that there were no issues with the HVAC systems or the building controls in this building.

2.14.2 HVAC Design Work

The only HVAC work in this facility is to provide a new BACnet router, temperature sensor and thermostat VLC/D. New building router shall be connected to the main controller (Model:

BCM/E) located in Building 63.

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2.4.2 HVAC Design Work

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