Energy Efficiency Guide for Colorado Businesses
Recommendations by Sector
School buildings are ordinarily built to last a long time, but many older schools are plagued with energy systems that waste energy, cause discomfort, and are costly to maintainâ€"or all three. Planning and executing a comprehensive retrofit can frequently alleviate all three problems cost-effectively. Lighting in many older schools constitutes 40% of the energy budget, followed by HVAC and plug loads at approximately 25% apiece and hot water at 10%. After reducing such internal loads as lighting, it may be possible to install smaller HVAC equipment.
Many programs aimed at improving the energy efficiency and physical plants of schools to enhance the educational environment are available. These range from U.S. DOE's Rebuild America/Energy Smart Schools Campaign and U.S. EPA's ENERGY STAR for Schools Program to the Sustainable Buildings Industry Council's High Performance School Building Program. The Consortium for Energy Efficiency maintains a directory of these programs at www.cee1.org/com/bldgs/ees_dir.pdf.
Measures that are frequently found to be very cost-effective include the following:
- Replace T-12 fluorescent fixtures with T- 8 or T-5 fixtures with electronic ballasts.
- Use compact fluorescent lights (CFLs) to replace incandescents and save energy and maintenance costs.
- Install and adjust automatic dimming controls to take advantage of daylighting.
- Install and adjust occupancy controls in spaces used intermittently like conference spaces, lounges, and storage rooms.
- Install LED exit signs.
- Upgrade parking lot lighting to save energy and reduce environmental impacts.
- Educate janitorial staff, students, and teachers to minimize the use of lighting.
- Consider retrofitting skylights in classrooms, gymnasiums, and media centers. If combined with a roofing retrofit (which may also include enhanced thermal insulation), the incremental cost of installing skylights may be diminished. Install light control by louvers or diffusers to avoid glare. Install and adjust automatic dimming controls to take advantage of daylighting.
- Install light shelves one-third of the way down existing window walls to direct light across the ceiling while shading lower glazing from direct beam solar, thereby avoiding glare. Accompany this retrofit with a fresh coat of semi-gloss white paint on the ceiling or install new light-reflective acoustical tiles.
- If light shelves are impractical, take advantage of existing windows to provide daylighting by using overhangs or other shading devices to keep direct beam solar from causing glare.
- Design supplemental electric lighting systems to optimize daylighting by specifying dimmable ballasts, photosensors, and daylighting controls. When installed, photocell daylighting controls should be carefully calibrated and tested. School building personnel should be trained in the use of this technology.
- The â€śCool Daylightingâ€ť approach helps to control for glare, achieves better light distribution, and lowers cooling costs (see www.daylighting.org/what_is_cool_daylighting.htm).
- Consider a modern two-pipe retrofit, particularly if adding air conditioning to previously un-air conditioned school buildings.
- Choose high-efficiency packaged A/C units listed by the Consortium for Energy Efficiency in their Tier 2 guidelines (www.cee1.org/com/hecac/ac_tiers/impcttbl.htm).
- Downsize to a new high-efficiency chiller in conjunction with lighting and other retrofits. Maintain chilled water temperature as high as practical.
- Consider using evaporative cooling.
- Use condensing boilers with large turn-down ratios whose efficiencies improve with turn-down. Maintain hot water temperatures as low as practical.
- Switch over to direct digital controls (from hydraulic or manual controls).
- Install variable air volume air handling systems with variable speed drives.
- Install premium-efficiency motors.
- Install demand-controlled ventilation to ensure good indoor air quality while minimizing energy use. This strategy is especially effective in intermittently used spaces such as auditoriums and gymnasiums, but is also useful in classrooms.
- Install energy-efficient unit ventilators with face and bypass controls.
- Upgrade the energy management system; optimize settings to reflect building usage, weather patterns, and to shave peak electric loads.
- Verify economizer function and control.
- Consider using cool air from the cooling tower with water-cooled chillers.
- Consider indirect-direct evaporative cooling.
- Install high-quality, low-flow shower heads. Lower hot water system temperature to 120 degrees.
- Insulate hot water lines wherever accessible.
- Replace chilled water drinking fountains.
- Install energy-efficient office equipment and use energy-saving features like sleep modes.
- Use the duplex mode on copying machines to save energy and paper.
- Educate students about energy efficiency. Involve them in turning off equipment and lights, and encourage their input in suggesting operational and retrofit options for saving.
- Continuously commission buildings; educate maintenance staff to anticipate as well as respond to energy-related problems.
- Install Vending Misers on vending machines.
Funding for this Guide provided by:
Recommendations for this and other sectors are available at www.coloradoefficiencyguide.com/recommendations.