Commercial Recommendations

LARGE OFFICE BUILDINGS

Energy Use

There is only a rough-and-ready distinction between small and large office buildings, but the demarcation line used here is around 50,000 square feet. The principal energy uses in most large office buildings are divided about evenly between lighting, HVAC, and plug loads. Since lighting, plug loads, people, and solar all provide heat that must be removed by the building’s cooling system, many large office buildings are in the cooling mode for most of the year, particularly during periods of substantial occupancy. Retrofit measures that improve the efficiency of lighting and office equipment, as well as those that improve windows and shading, can lower the demand on the cooling system. Combined with such retrofits, oftentimes an energy-efficient new chiller can be installed that is substantially downsized from the old one. This can result in both initial and life-cycle savings that are quite substantial.

Measures that are often found to be very cost-effective include the following:

High-efficiency lighting

• Replace T-12 fluorescent fixtures with T- 8 or T-5 fixtures with electronic ballasts.
• Install and adjust automatic dimming controls to take advantage of daylighting. The “Cool Daylighting” approach keeps most outside light out of view, thereby controlling for glare, producing better distribution, and lowering cooling costs (see www.daylighting.org/what_is_cool_daylighting.htm).
• Install and adjust occupancy controls.
• Install LED exit signs.
• Upgrade parking lot lighting to save energy and reduce the environmental impacts associated with lighting the sky instead of the parking lot.

Find a list of ENERGY STAR-qualified CFL bulbs at www.energystar.gov/ia/products/prod_lists/cfl_prod_list.pdf. A list of ENERGY STAR-qualified LED exit signs can be found at www.energystar.gov/ia/products/prod_lists/exit_signs_prod_list.pdf.

High-efficiency HVAC

• Install a water-cooled chiller.
• Downsize to a new high-efficiency chiller in the light of lighting and other retrofits.
• Use condensing boilers with large turn-down ratios whose efficiencies improve with turn-down.
• Switch over to direct digital controls.
• Install variable air volume air handling systems with variable speed drives.
• Install premium-efficiency motors.
• Install demand-controlled ventilation.
• Ventilate garages in response to environmental conditions.
• Upgrade the energy management system; optimize settings to reflect usage, respond to changing weather patterns, and control peak electric loads.
• Continuously commission the building.
• Verify economizer function and control.
• Consider using cool air from the cooling tower with water-cooled chillers.
• Consider indirect-direct evaporative cooling.

The Consortium for Energy Efficiency designates specifications for high-efficiency commercial packaged air conditioning equipment and maintains a database of qualifying products at www.cee1.org.

Combined Heat and Power (CHP) System

• Investigate installing a combined heat and power system with a waste heat-fired absorption chiller to supply the office’s electricity, heating, and cooling needs. When properly sized and designed, such a system can save substantial money, avoid the large thermal losses associated with conventional power generation at utility plants, avoid the transmission and distribution losses associated with delivering the power over power lines, and avoid separate fuel usage for heating. When a waste heat-fired absorption chiller is part of the CHP system, it can drastically cut down on peak-time electricity used for cooling loads.

Learn more about CHP on the CHP Energy Efficiency Measures page, or by visiting the website of the Intermountain CHP Center. The Center works in the areas of project support and facilitation, education and outreach, market assessment, policy review, and coalition building. Visit the Intermountain CHP Buyer’s Guide website to access information about vendors, contractors, and distributors who can turn your project idea into reality.

Building Envelope

• Install high-efficiency, specularly-selective glazing carefully chosen for solar interactions with the building facade and other variables.
• Install interior or exterior shading devices.
• Install insulation in strategic locations.
• Undertake strategic air sealing, including duct work.

Learn more on the Building Envelope Energy Efficiency Measures page.

Plug Loads

• Use low-energy sleep functions on computers and printers.
• Choose ENERGY STAR office equipment and appliances.

Details on office equipment that meet ENERGY STAR criteria for energy efficiency are available at www.energystar.gov/index.cfm?c=ofc_equip.pr_office_equipment.

Employee

• Ensure building maintenance and cleaning staff are enthusiastic about savings and adopt work habits that support energy efficiency.
• Provide training for key maintenance personnel in the proper operation of the building’s energy management system.
• Involve all employees in energy savings efforts, provide efficiency education for work and home, and encourage employee suggestions on energy savings opportunities.

Benchmarking

The U.S. Environmental Protection Agency and Department of Energy through the ENERGY STAR® Program have developed an energy performance benchmarking tool. The tool enables building owners to evaluate the energy performance of their buildings on a scale of 1-100 relative to similar buildings nationwide. The rating system accounts for the impacts of year-to-year weather variations, as well as building size, location, and several operating characteristics. Buildings rating 75 or greater qualify for the ENERGY STAR label.

Eligible space types, representing over 50% of U.S. commercial floor space, include:

• Offices (general offices, financial centers, bank branches, and courthouses)
• K-12 Schools
• Hospitals (acute care and children's)
• Hotels and Motels
• Medical Offices
• Supermarkets
• Residence Halls
• Warehouses (refrigerated and non-refrigerated)

For further information or to download the performance benchmarking tool, see www.energystar.gov/index.cfm?c=evaluate_performance.bus_announcing.

Assistance

Utah Power has a host of programs targeted to meeting its customer’s energy efficiency needs. Visit the Utah Power profile page by clicking here.

© 2006 Southwest Energy Efficiency Project
2260 Baseline Road, Suite 212, Boulder, CO 80302
(303) 447-0078 fax: (303) 786-8054 info@swenergy.org