Energy Efficiency Guide for Colorado Businesses

Recommendations by Sector

LABORATORIES

Energy Use

These notes address laboratories generally, from biological or chemical facilities at universities to experimental and production facilities operated by industrial concerns. Most such facilities have very high energy use, primarily due to large HVAC demands. Because of the risk of microbial or chemical contamination, high ventilation rates with 100 percent fresh air are required in laboratory areas because conditioned air cannot be circulated as is the case with most other buildings. Some laboratories also have significant process loads for sterilization or for the need to maintain computer, animal, or equipment areas at specific temperatures. Plug loads for serving special purpose equipment, much of which must be functioning 24 hours per day, also contribute to high electric energy use.

Efficiency measures that are frequently found to be cost-effective include the following:

HVAC

• Separate areas in the building that must have once-through air from those which can recirculate air. This allows for substantial economies in the areas where air may be recirculated. Care in air sealing the environmentally-sensitive areas from those where air is recirculated is essential, and environmentally-sensitive areas should be maintained at negative air pressure with respect to the remainder of the building.
• Use modern variable air volume (VAV) fume hoods equipped with occupancy sensors. VAV systems respond to the degree to which the hood is opened so as to maintain constant negative pressures across the opening to whisk potentially contaminated air up the exhaust. Occupancy sensors which increase hood exhaust rates when scientists are using the system further protects air quality and user health while maintaining flows that are as low as practical.
• Use high-efficiency motors with variable speed drives to adjust exhaust and make up air fans in HVAC systems serving laboratory areas. Employ controls that vary air flow rates in response to instantaneous exhaust hood usage. When fume hoods are used only moderately, air exchange rates may be safely lowered, thereby saving substantial fan power and conditioning energy. When laboratories are equipped with modern fume hoods with VAV equipment, it is frequently possible to downsize HVAC system fans.
• Recover heat from central plant equipment by installing heat-recovery coils in the exhaust air handlers to capture waste energy without the risk of contamination.
• Recover waste heat from exhaust stacks of boilers to preheat boiler makeup water or combustion air.
• Recover heat from sterilization equipment, laundries, dishwashers, and cleaning equipment to pre-heat fresh hot water.
• Install a waterside economizer for nighttime and winter cooling.
• Install a high-efficiency chiller in new facilities or existing facilities when replacing an older chiller. Right-size the chiller in consideration of other efficiency measures that lower cooling loads, like energy-efficient lighting.
• Use condensing boilers with large turn-down ratios whose efficiencies improve with turn-down.
• Switch over to direct digital controls.
• Upgrade the energy management system; optimize settings to reflect usage, respond to changing weather patterns, and control peak electric loads. Lights and air conditioning in spaces occupied only during business hours are often left on all the time. The energy management system can automatically shut off lighting and set back HVAC systems in spaces occupied only during the daytime. A combination of occupancy sensors and time switches can accommodate scientists who arrive early or stay after the end of the business day.
• Verify economizer function and control.
• Consider using cool air from the cooling tower with water-cooled chillers.
• Consider indirect-direct evaporative cooling.

Combined Heat and Power (CHP) System

• Install a combined heat and power generation system to supply electricity, heating needs, and (through an absorption chiller) cooling needs. When properly sized and designed, such a system can save substantial money and avoid the large thermal losses associated with conventional power generation at utility plants.

Lighting

• Install compact fluorescent bulbs in place of incandescents in laboratories, halls, and elevators.
• Install energy-efficient lighting in all other spaces, being sure to replace T-12 fixtures with T-8 or T-5 fixtures with electronic ballasts.
• Install and calibrate automatic lighting controls in conjunction with skylights and clerestories in open areas to dim lights in response to daylight.
• Install LED exit signs.
• Upgrade parking lot lighting to save energy and reduce environmental impacts due to light spillage.
• Upgrade garage parking lighting.

Building Envelope

• Install high-efficiency, specularly-selective glazing carefully chosen for sun exposure on each facade and other variables. ENERGY STAR windows with low solar heat gain coefficients are frequently good choices.
• Install interior or exterior shading devices.
• Install insulation in strategic locations.
• Undertake strategic air sealing, including duct work.
• Install an ENERGY STAR rated cool roof.

Plug Loads

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

Employee

• Ensure that key maintenance people are trained to properly use and monitor the building's energy management system.

 

Funding for this Guide provided by:

Colorado Governor's Energy Office

U.S. Environmental Protection Agency - Region 8

Southwest Energy Efficiency Project

Recommendations for this and other sectors are available at www.coloradoefficiencyguide.com/recommendations.