Longer-term energy-saving solutions should also be considered. Although the conservation measures covered in this section require more extensive implementation and larger monetary expenditures, they represent good investments for colleges and universities. Most will not only save money, but will also enhance the learning environment and the comfort of your buildings. Ask your local utility representative for more information about initiating such projects.
Commissioning or Recommissioning
Commissioning is the process of ensuring that systems are designed, installed, functionally tested, and capable of being operated and maintained according to the owner’s operational needs. By utilizing building inspection and systems testing, commissioning can provide quality assurance and systematically improve the efficiency and operation of building energy systems (particularly HVAC and air-distribution systems). For a typical 50,000-ft2 university building, commissioning can often uncover around $17,000 or more in annual savings, yielding simple payback periods of just a year or two. In addition to providing energy savings, commissioning often increases comfort for occupants.
When the commissioning process is applied to an existing building that hasn’t been commissioned before, it’s called retrocommissioning. When it’s applied to a building that has been commissioned before, it’s called recommissioning, which is good to do every three to five years to maintain top levels of building performance. In another type of commissioning—ongoing commissioning—monitoring equipment is left in place to allow for continuing diagnostics. For more information, see the Lawrence Berkeley National Laboratory (LBNL) report Building Commissioning: A Golden Opportunity for Reducing Energy Costs and Greenhouse Gas Emissions.
Fluorescent lamps. If your facility still uses T12 fluorescent lamps or commodity-grade T8 lamps, relamping with high-performance T8 lamps and electronic ballasts can reduce your lighting energy consumption by 35 percent or more. Adding specular reflectors, new lenses, and occupancy sensors or timers can double the savings. Paybacks of one to three years are common.
Daylighting. In classrooms and administration buildings, take advantage of daylighting where possible to reduce the need for electric light and improve the ambience of the space. Dimming ballasts and daylighting controls can reduce the amount of electric light used when daylight is present. Solar light tubes can also often be a cost-effective retrofit. However, be careful to employ proper design when implementing daylighting in order to avoid glare and overheating.
LEDs. LED lighting has rapidly improved in performance and decreased in cost to the point where there are very few applications for which LEDs don’t at least merit consideration—they won’t always be cost-effective, but they’re worthy of consideration. But exercise caution in specifying LED products—they’re not all equally effective. To keep abreast of developments in the field, visit the US Department of Energy’s (DOE’s) Solid State Lighting website.
Integral lamps, which feature an LED-and-driver package that can be installed as a single unit in a conventional socket, are available in the full range of lamp types, including A-lamps (the technical term for the commonly used lightbulb), PAR (parabolic aluminized reflector) lamps (which are used to direct light in flood or spot patterns), and others. Compared to the halogen and CFL alternatives, LEDs offer longer life and higher efficacy. LEDs are still more expensive than CFLs or halogen lamps, but prices are falling, making them worth consideration in areas like dorm rooms where integral lamps are prolific and frequently left on for extended periods of time.
For ambient lighting, LED troffers—more so than tubular LED lamps—have become an effective alternative to linear fluorescent fixtures. Found in many classrooms and other campus facilities, troffers are long, recessed lighting fixtures that are typically installed with the opening flush with the ceiling and with their inner surface serving as a reflector. The DOE’s Exploratory Study: Recessed Troffer Lighting (PDF) reported on the results of the testing of LED troffers and LED tubular products installed in a mock office space. In addition to providing objective measurements, the study also shared the observations of a group of lighting designers, engineers, and facility managers. Researchers concluded that LED troffers can compete with fluorescent fixtures in lighting-quality factors such as glare, light distribution, visual appearance, and color quality. The only caveat: Some of the products flicker when dimmed, so it’s important that LEDs be compatible with the dimming products they’re paired with.
Finally, replacing fluorescent or incandescent task lamps with LED versions can save significant amounts of energy. The directional nature of LEDs allows task lamps to be oriented to illuminate only the working area without wasting energy by using a reflector or lighting unused areas. These savings can be further enhanced by delamping unnecessary overhead lighting and using occupancy sensors, which dim or turn off lamps at unoccupied desks.
Smart lighting design in parking lots. Parking lots are often overlit—an average of 1 foot-candle of light or less is usually sufficient. The most common lamps used for outdoor lighting are high-intensity discharge (HID) sources—metal halide (MH) and high-pressure sodium. In recent years, fluorescent lamps, CFLs, and induction lamps have also become viable sources for outdoor lighting, offering good color quality and better control options than HID sources. But LEDs are quickly becoming the go-to option because they can reduce light pollution while still offering high efficiency and long life. Dimming (for example, bi-level lighting) and occupancy-sensing controls can also add to energy savings in parking lots. For more information, including analysis tools and case studies, visit the Lighting Energy Efficiency in Parking Campaign website.
Stadium and arena lighting. Using LEDs to light stadiums and sports arenas can yield massive energy savings—roughly 75 percent over the commonly used MH lamps—while also reducing maintenance costs via the bulbs’ longer lamp life and lower lumen depreciation rates. Unlike MH lamps, LEDs also offer instant-on and instant-restrike capabilities, which can be appealing to facilities operators. The latest LED fixtures also provide light of sufficient quality for high-definition broadcasts. Although prices vary, LED fixtures can currently cost up to four times as much as MH fixtures, but the dramatic energy and maintenance savings can make them an economical measure with potential simple payback periods of just two to three years.
LEDs can also be used at sports and entertainment venues for lighting façades, concourses, suites, bathrooms, locker rooms, and video boards. Examples of LEDs used in non-field lighting applications can be found in the Natural Resources Defense Council report Game Changer: How the Sports Industry Is Saving the Environment (PDF).
High-efficiency HVAC units. A high-efficiency packaged HVAC unit can reduce cooling energy consumption by 10 percent or more over a standard-efficiency, commercial packaged unit. Select equipment that has multiple levels of capacity (compressor stages) with good part-load efficiency.
Demand-controlled ventilation. For spaces that have large swings in occupancy (such as auditoriums, gyms, classrooms, and cafeterias), energy can be saved by decreasing the amount of ventilation supplied by the HVAC system during low-occupancy hours. A demand-controlled ventilation system senses the level of carbon dioxide in the return air stream, uses it as an indicator of occupancy, and decreases supply air when carbon dioxide levels are low.
Reflective roof coatings. If facility roofs need recoating or painting, consider white or some other highly reflective color to minimize the amount of heat the building absorbs. Cool roofs can often reduce peak cooling demand by 10 to 15 percent. For a list of suitable reflective roof coating products, see the Energy Star Roof Products website.
Water Use and Heating Systems
Low-flow faucets and shower heads as well as sink and shower controllers that automatically shut off can help conserve water and the energy used to heat water in recreational buildings. For dorms and recreation facilities, tankless water heaters can typically be used instead of traditional tank-type water heaters.
Gray-water heat-recovery systems can save 50 to 60 percent of water-heating energy when installed in shower drains, resulting in short payback times (especially in buildings with substantial hot water usage, such as recreational centers and dorms). Drainpipe heat exchangers also double or triple the first-hour capacity of water heaters. The equipment consists of a replacement section of pipe that diverts incoming cold water to a coil wrapped around the drain through which hot wastewater flows, heating the fresh intake water. These systems are only effective when hot water is needed at the same time that heated wastewater is generated—as is the case for showers, laundry machines, and dishwashers.
Savings from boiler retrofit projects can be significant. Newer boilers feature a variety of efficiency improvements that can justify the replacement of older boilers before failure. Improvements include condensing heat exchangers, sealed combustion, electric ignition, and fan-assisted combustion. Smaller boilers are more efficient than large ones, and grouping multiple smaller boilers not only allows staged operation of each unit at its highest efficiency point, it also provides redundancy. If a larger boiler isn’t ready to be retired, a smaller boiler can be added to serve the base heating load, reserving the larger boiler for additional heating as needed.
Laboratory Air Filtration
As filters accumulate dust, the airflow through them drops, causing drops in air pressure, which increases the energy required to push air through the filter. Choosing filters rated for the lowest possible pressure drop will cost more up front, but usually ensures lower energy costs because there’s less resistance in the ventilation system. You can also save energy and lengthen the functional life of filters by “under-rating” your system. That is, if you force less air through the filter than the maximum amount it’s rated to handle (over a specified unit of time), it will last longer and use less energy. For more information, see the filtration section of A Design Guide for Energy-Efficient Research Laboratories by LBNL.
Life-Cycle Costs for Equipment Procurement
Identify who is responsible for setting equipment procurement policies for your campus. Is it the Board of Regents or the state? Or is it individual schools and departments? Encourage those in charge to include consideration of energy costs and life-cycle costs in the procurement rules.