Building Statistics
Part 1_General Building Data
- Building name: CareFirst Cumberland
- Location and site: Cumberland, MD
- Building occupant name: CareFirst of Maryland, Inc.
- Occupancy types: Office
- Size: 46,739 SF
- Number of stories: 2 Floors above grade
- Primary project team
- Dates of construction: March 2010- May 2011
- Actual cost information $13,000,000
- Project delivery method : Design-Bid-Build
Architecture
CareFirst is simple rectangular shaped 2-story office building above grade level in Cumberland, Maryland. Since the CareFirst moved into new building for lack of the spaces, the new facility provides more than 200 workstations, glazed cafeteria with patio and outdoor seating, geothermal heating/cooling system, two training rooms, two multi-purpose rooms, and room for future expansion.
Building Enclosure
CareFirst’s façade is a combination of stone, metal, and glass. The corner and center of building of east and west façade is consist aluminum curtain wall, and masonry capstone is used only at center. Overall building envelopment represents with masonry cladded wall and storefront window system. The building has 1 ½” galvanized metal roof deck, ½” roof board, 4” rigid polyisoprene insulation, and SBS (styrene-butadiene-styrene) roofing on the top.
Sustainability Feature
- Daylights for cafeteria and offices
- Geothermal heating/cooling system
Part 2_Primary Engineering System
Construction
CFBC Properties, LLC contracted with Carl Belt, Inc. as the construction manager. Total design and construction cost calculated to $13 million.
Mechanical
The core mechanical system for CareFirst Cumberland contained ground source heating and cooling system. Thirty of geothermal wells located vertically in below the site of the CareFirst Cumberland, these wells serve both of heating and cooling since the Earth’s surface maintains a nearly temperature between 50 to 60 °F. The primary pumps are 230 GPM, 15 HP, and variable speed. One pump is used for stand-by. Auxiliary boiler and cooling tower are also connected in case of the temperature of water is above or below set-point.
The air-side of the mechanical system of CareFirst Cumberland located on roof. The roof top unit served as Dedicated Outdoor Air System with heat recovery unit. Total 9,000 CFM of outdoor air supply with 15 HP and exhaust 5,500 CFM of air with 5 HP.
The total 45 individual heat pump units are water source heat pumps those located each zone. The total 106 GPM and 9,000 CFM heat exchanged and the system consists of 525 MBH in summer. For winter, total 228 MBH hot gas reheat and 45 MBH electrical preheat consist.
Some energy efficiency features in the mechanical design include in CareFirst Cumberland. Operating pumps using variable speed drive controllers, temperature sensor and 3-way valve, operating air handling units using variable speed drive controllers, and heat exchange from exhaust to supply air.
Electrical
The main switchboard for the CareFirst Cumberland uses 277/480 V, 3 Phase, 4 wire and ground, with main bus of 1600 amps. Total connected load is 1200 kVA and overall demand load is 900 kVA. The largest loads on the CareFirst Cumberland consumed at 45 individual heat pump units. Total 17 panels serve electrical system of the CareFirst Cumberland, and the one uninterrupted power source panel connected in to the IT and security system.
Lighting
The lighting design of the CareFirst Cumberland is usual for office building using 2 x 2 recessed florescent lights with T5HO lamps. Overall office area designed with this and one or two light fixtures in individual office serve as emergency lights. For the breakout room and lobby space, linear Fluorescent staggered strips are used to illuminate along with the path of occupants. Open office area on 2nd floor also provides lightings with 2 x 2 recessed florescent lights with T5HO lamps.
Structural
The CareFirst Cumberland uses a steel framing on top of a concrete foundation. The foundation is to be 4” or 6” thickness on polyethylene over 6” of washed gravel. Typical footing for the columns is 6’ x 6’ and corner foot if 6’ x 12’. Typical 24K8 steel joist and W27 girder supports the joists. Over the steel framing, 4” normal weight concrete slab on galvanized steel deck serve as floor system on 2nd floor of the CareFirst Cumberland. For the enclosure staircase, the lateral brace frame support and separated the staircase from the building for fire protection reason. Roofing system supported by 1.5” galvanized steel deck over open web steel joist to support snow load and live load. Two of W16 x 31 girders placed underneath the roof top unit to support the concentrated dead load on roof.