DEP Cambria

Ground-source heat pumps are linked to a closed-loop, ground-source heat pump well field that provides HVAC heating and cooling supply as well as domestic hot water heating. Raised-access flooring provides an underfloor supply air plenum for displacement heating and cooling air distribution through floor-mounted air diffusers.

A 14.3 kW PV array mounted on south-facing sloped roofs provides 28% of the total energy costs. Several of these PV panels are mounted on solar tracking devices.

Heat recovery air-handling units provide ventilation make-up air separated from conditioned air, thereby allowing for conditioned air equipment to be shut off when not needed. Ventilation air is preconditioned through energy recovery, which also provides the necessary dehumidification for the system.

Fourth-generation design of light shelves on south-facing windows increases lighting levels by reflecting natural light deeper into interior spaces; at the same time, cooling loads are reduced by shading windows from exposure to summer solar radiation.

Site-specific reverse-baffle solar shading devices were designed to shade other south-facing windows from high-altitude summer sun while allowing low-altitude winter solar radiation to penetrate into interior spaces. Second floor south-facing windows are shaded via integral roof overhangs.

Lighting power density is reduced to an average of less than 0.75 W/ft2 (8 W/m2), which significantly reduces both electrical energy consumption and cooling loads. This was accomplished by integrating the following components: split task/ambient lighting scheme; indirect fluorescent lighting fixtures with T-8 lamps and electronic dimming ballasts controlled by light-level sensors; natural daylighting via clerestory window monitors; occupancy-sensored switching at workstations, toilet rooms, and conference rooms; roll-down solar shades and south-facing windows; compact fluorescent lighting fixtures with vertical lamp configurations; and LED exit signs.

Manufactured wiring distribution systems incorporate relocatable floor boxes mounted in access floor panels with quick-disconnect cabling to provide maximum flexibility for tele-data and power provisions. Such flexibility supports workstation reconfigurations and minimizes chum rate costs.

The building's thermal envelope achieves high-performance levels by integrating exterior walls constructed of highly insulating—R-30 (RSI-5.3)—EPS structural concrete wall forms; high-density fiberboard roof decking laminated with an interior reflective surface coupled with 4 in. (100 mm) of rigid polyisocyanurate insulation to provide a composite roof insulation of R-33 (RSI 5.8); pre-manufactured aluminum-clad windows which provide triple-glazed, low-e coated, argon-filled insulating glass with a whole-unit U-value of 0.29 (1.6 W/m2*C); storefront window fabrication including high-performance, thermally broken frames and triple-glazed, low-e coated, argon-filled insulating glass with a whole-unit U-value of 0.26 (1.5 W/m2*C); and a concrete floor slab on grade which is insulated with 2 in. (50 mm) of EPS rigid insulation.

This high-performance thermal envelope, in conjunction with space planning that locates no workstations directly adjacent to window walls, eliminated the need to design separate perimeter thermal zones and supplemental perimeter heating systems.

All of the above systems are integrated to achieve an annual energy consumption, as currently simulated, that exceeds the requirements of ASHRAE/IES Standard 90.1, 1989 by 30% and equates to less than 40,000 Btu/ft2 (450 MJ/m2).

Systems integration also reduced nominal cooling capacity to 52 tons (183 kW), which equates to only 658 ft2/ton (58 W/m2).

Building commissioning is specified according to the Bonneville Power Administration's Building Commissioning Guidelines. The building is equipped with permanently installed energy consumption monitoring equipment.