Colleges and universities in the US use an average of 18.9 kilowatt-hours (kWh) of electricity and 17 cubic feet of natural gas per square foot (ft2) of floorspace each year. Typical US higher-education buildings sized around 50,000 ft2 consume more than $100,000 worth of energy each year. Lighting, ventilation, and cooling equipment consume the most electricity, and space heating accounts for the majority of natural gas use (figure 1). As a result, these technologies are among the best targets for finding energy savings. Many colleges and universities can cut their energy bills by 30% or more by implementing cost-effective energy-efficiency measures.
Average energy-use data
When you understand your facility’s energy consumption, you can better control costs. Utilities can provide monthly usage data for your analysis, and some utilities will also assist with the analysis. In general, utilities charge commercial buildings for their natural gas based on the amount of fuel delivered. But they charge for electricity based on two measures: consumption and demand.
The consumption component of the bill is based on the amount of electricity, in kilowatt-hours, that the building consumes during a month. The demand component is the peak demand, in kilowatts, that occurs within the month. Monthly demand charges range from just a few dollars to nearly $20 per kilowatt and can be based on the highest peak recorded in the previous 12 months. This charge can be a considerable percentage of your bill, so reduce peak demand whenever possible. Figure 2 shows a sample daily load profile.
As you read the following recommendations to manage energy costs, keep in mind how each will affect consumption and demand. These conservation measures will save money and enhance both the aesthetics and the learning environment of your campus. You can find more information and other strategies in these resources:
- Tools and Resources for higher education, ENERGY STAR
- Association for the Advancement of Sustainability in Higher Education (AASHE)
- Labs21 Tool Kit, International Institute for Sustainable Laboratories
Many colleges and universities have tight operating budgets, so it’s especially important to find low- or no-cost ways to reduce energy expenses. Engaging students and faculty in energy conservation can also save on campus energy bills. Students are often the biggest advocates for energy efficiency and are likely to respond enthusiastically to educational initiatives and conservation pledge campaigns.
Turn things off
This simple advice may not seem like it will make a significant difference, but remember that every 1,000 megawatt-hours saved by shutting off equipment and appliances takes $120,000 off your institution’s utility bill annually (assuming electricity costs of $0.12/kWh).
Computers and monitorsComputers and other electronic equipment are abundant in campus buildings and contribute considerably to overall energy consumption and cost per square foot. You can save energy by activating computer power management settings on individual computers and monitors, setting them to enter sleep mode after a specified period of inactivity. Effective power management settings can cut a computer’s electricity use in half, saving up to $75 annually per computer. Although most computers now come with some sort of power management settings enabled, users or internal IT staff might disable them. Be sure they’re enabled and set to maximize energy savings. For detailed instructions, see the ENERGY STAR page The Business Case for Power Management. Some users may think that enabling power management settings will block automatic software updates, but that’s not the case. Updates will download automatically when the computer awakens from sleep mode.
Other plug loadsDevices such as printers and faxes also have energy-reduction settings. Be sure these settings are enabled, and use smart power strips to shut off plugged-in devices such as printers, monitors, other computer peripherals, water coolers, and coffeemakers when not in use.
LightsMany people forget this simple step, but turn off lights when they’re not being used. To ensure that switches are off whenever possible, install occupancy sensors or recruit staff to serve as “energy monitors” in each building. Place energy conservation–themed posters and stickers around campus. They’re effective reminders, especially when designed as part of a larger energy-awareness campaign.
Laboratory vent hoodsVent hoods are among the most energy-intensive equipment on college campuses and should be kept off unless they’re needed for experiments or appropriate material storage.
Prewash sprayers in kitchensKitchen staff use prewash sprayers to remove food from dishes, utensils, pots, and pans before placing them in a dishwasher. Sprayers can use up to 5.0 gallons per minute (gpm), but low-flow sprayers limit the flow rate to 1.6 gpm. Given the minimal cost of installing low-flow valves, the payback period for this upgrade is typically less than two months when you consider both water and water-heating savings.
Chilled-water drinking fountainsYou can turn off the cooling systems in many drinking fountains because they generally don’t need to provide ice-cold water 24 hours a day (unless it’s required for health reasons).
Turn things down
Building automation systemsMake sure temperature setbacks are coordinated with building occupancy patterns each quarter or semester. Facility engineers should coordinate with campus staff to align the HVAC schedules in the building automation system (BAS) with expected occupancy to optimize energy usage. Identify buildings that aren’t used at night, on weekends, or for long periods of time (such as semester breaks), and adjust temperature settings in those locations. Also, check that HVAC systems aren’t set to overcool or overheat buildings. For facilities with regular occupancy schedules but without a BAS, use programmable or cloud thermostats to plan temperature setbacks.
Water heatersReduce setpoint temperatures of water heaters in buildings that don’t have laboratory or cooking facilities while still adhering to health requirements. You may also find that the water temperature is set higher than necessary in residential buildings. A setpoint of 120° Fahrenheit (F) measured at the furthest hot water fixture from the water heater is usually sufficient.
Vending machinesRefrigerated vending machines typically operate 24-7, using 2,500 to 4,400 kWh per year and giving off heat, which increases the need for cooling in the surrounding area. Timers or occupancy sensors can yield significant savings because they allow the machines to turn on only when a customer is present or when the compressor must run to maintain the desired temperature. When it’s time to replace or add vending machines in your facilities, look for ENERGY STAR–qualified models. Each one can save over $150 annually on utility bills.
HVAC operations and maintenance
Performing regularly scheduled maintenance and periodic tune-ups saves energy and extends the useful life of your HVAC equipment. Create a preventive maintenance plan that includes cleaning, calibration, component replacement, and general inspections. Be sure information on setpoints and operating schedules is available to technicians when they check or recalibrate the equipment.
Check the economizerMany air-conditioning systems (other than those in hot and humid climates) use a dampered vent called an economizer to reduce the need for mechanically cooled air by drawing cool outside air into the building. But if the economizer isn’t checked regularly, the linkage on the damper can seize up or break, keeping the airway open. An economizer that’s stuck open can add as much as 50% to a building’s annual energy bill by allowing hot air in during the air-conditioning season and cold air in during the heating season. About once a year, have a licensed technician check, clean, and lubricate economizers and repair them if necessary. Calibrate the controls at this time too.
Check air-conditioning temperaturesWith a thermometer, check the temperature of the return air going to your air conditioner and then check the temperature of the air coming out of the register that’s nearest the air-conditioning unit. If the temperature difference is less than 14°F or more than 22°F, have a licensed technician inspect your air-conditioning unit.
Optimize temperatures in peripheral roomsMake sure that HVAC settings in stockrooms and other rarely used rooms are at minimum comfort settings.
Use window shades and blindsIn warm weather, lower blinds to block direct sunlight and reduce cooling needs. When it’s cold, open the blinds on south-facing windows to let in sunlight and help heat the space.
Clean condenser coilsCheck condenser coils quarterly because debris can collect in them. At the beginning and end of the cooling season, thoroughly wash the coils.
Change filtersChange air filters every one to six months, depending on the level of pollutants and dust in the indoor and outdoor air. In systems that use economizers, change filters more often because outdoor air is usually dirtier than indoor air.
Check cabinet panelsOn a quarterly basis (or after you change the filters), make sure the panels to your packaged rooftop air-conditioning unit are fully attached, with all screws in place and all gaskets intact so that no air leaks out of the cabinet. Chilled-air leaks can cost $100 in wasted energy per rooftop unit per year.
Follow a steam trap inspection and maintenance planSteam traps remove water from the steam distribution system once it has cooled and condensed in radiators or other heat exchangers. Mechanical steam traps can become stuck open, which wastes heat. A single failed trap can waste more than $50 per month, and a university might have thousands of steam traps on campus.
Optimize chiller sequencingOperators often run too many chillers for a given load, which wastes energy and degrades chiller equipment. Verify your full- and part-load requirements and sequence your chiller systems to only operate within their most efficient performance range.
Operate multiple cooling towers to save fan powerMost chilled-water plants have excess capacity, and during low-load hours, at least one cooling tower won’t be operating. To make the most of your existing cooling towers, run condenser water over as many towers as possible, at the lowest-possible fan speed, and as often as possible.
Encourage energy-saving behavior
Several colleges and universities successfully use no- and low-cost public-awareness campaigns to reduce energy use on campus. One popular and effective program is the “Dorm Energy Challenge,” in which residence halls compete against one another to make the largest energy reductions or simply to improve their own energy performance. Other popular programs include “Green Crib Certified” awards for students with eco-friendly dorm rooms and “Eco Reps” programs to encourage peer-to-peer sustainable behavior in residence halls. For more information on these kinds of programs, see the AASHE’s Resources page.
Although the conservation measures covered in this section require more involvement and expense, they’re worthwhile investments. Most won’t only save money but will also enhance the learning environment and the comfort of campus buildings. Ask your local utility representative for more information about initiating these projects.
Commissioning or recommissioning
Commissioning is the process of inspecting and testing that ensures systems are designed, installed, and able to operate and be maintained according to the owner’s needs. 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 $17,000 or more in annual savings, yielding simple payback periods of just a year or two. Besides providing energy savings, commissioning often increases comfort for occupants.
When you commission an existing building that hasn’t been commissioned before, it’s called retrocommissioning. When a building has been commissioned before, it’s called recommissioning. Recommissioning should happen every three to five years to maintain top levels of building performance. In another type of commissioning—ongoing commissioning—energy managers leave monitoring equipment in place to perform diagnostics continually. 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 lampsIf 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% or more. Add specular reflectors, new lenses, and occupancy sensors or timers and the savings may double. Payback periods of one to three years are common.
Install LEDs—in the form of replacement tubes, retrofit kits, or new fixtures—to save considerable energy even when compared to the best fluorescent options. Products vary in performance, so select them carefully.
DaylightingIn 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 to avoid glare and overheating.
LEDsLEDs offer several advantages over conventional light sources, including high efficiency, long life, and superior control. These characteristics and falling prices have made LEDs a viable solution for a growing number of office-building applications, including exit signs, task lighting, recessed downlighting, and ambient lighting.
LED troffers offer promising benefits in the right applications. Fluorescent troffers are the most common type of lighting fixture found in US commercial facilities, accounting for 50% of existing units. The best LED troffer products outperform their fluorescent cousins, but at a first-cost premium. You can replace fluorescent troffers with new LED troffers, via LED retrofit kits, or by replacing the fluorescent tubes with tubular LED products.
Replacing fluorescent or incandescent task lamps with LED versions can also save significant amounts of energy. The directional nature of LEDs allows users to illuminate only the working area without wasting energy by using a reflector or lighting unused areas. You can save even more by delamping (removing or disabling) unnecessary overhead lighting and using occupancy sensors, which dim or turn off lamps at unoccupied desks.
When buying LED products, ask for performance data based on standard tests performed by accredited laboratories. When comparing LEDs to other options, be sure to include in the total calculation the cost savings from reduced lighting maintenance due to LEDs’ long lifetimes. Make sure that the LED solution will provide the quantity and quality of light you need by starting with a small test case.
Smart lighting design in parking lotsIn parking lots, an average of 1 foot-candle of light or less is usually sufficient. But lots are often overlit, which means there’s potential to save energy by delamping, adding dimming controls, or adding occupancy sensors. Overlit parking areas not only waste energy but can actually be dangerous if drivers have trouble adjusting their eyes between highly lit and dark areas. It’s important to find a balance to prevent safety concerns involved with underlighting.
The most common lamps used for outdoor lighting are high-intensity discharge (HID) sources—metal halide (MH) and high-pressure sodium (HPS). Fluorescent lamps, induction lamps, and LEDs are also viable sources for outdoor lighting, offering good color quality and better control than HID sources.
LEDs are an especially good choice for parking and streetlighting applications because LED fixtures perform well in the cooler conditions that are typically found outside at night. LEDs also reduce light pollution and work better with controls than HID products. Field testing of bi-level LED lighting combined with occupancy sensing at a parking garage on the California State University campus in Sacramento revealed energy savings of 78% between the hours of midnight and 6:00 a.m. because the majority of fixtures were operating in low-capacity mode. The project report, Bi-level LED Parking Garage Luminaires (PDF), prepared by the California Lighting Technology Center, also noted 24-hour energy savings of 68% compared to the incumbent HPS lighting system.
Stadium and arena lightingUsing LEDs to light stadiums and sports arenas can yield massive energy savings—roughly 75% over the commonly used MH lamps. LEDs also reduce maintenance costs via the bulbs’ longer lamp life and lower lumen depreciation rates. Unlike MH lamps, LEDs offer instant-on and instant-restrike capabilities. The latest LED fixtures also provide light of sufficient quality for high-definition broadcasts. The dramatic energy and maintenance savings deliver a simple payback period of 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. See the Natural Resources Defense Council report Game Changer: How the Sports Industry Is Saving the Environment (PDF) for examples of how to use LEDs in nonfield lighting applications.
High-efficiency HVAC unitsA high-efficiency packaged HVAC unit can reduce cooling energy consumption by 10% 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 ventilationIn spaces that have large swings in occupancy (such as auditoriums, gyms, classrooms, and cafeterias), save energy 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 airstream, uses it as an indication of occupancy, and decreases supply air when carbon dioxide levels are low.
Reflective roof coatingsIf 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 reduce peak cooling demand by 10% to 15%. For a list of suitable reflective roof coating products, see the ENERGY STAR Roof Products page.
Water use and heating systems
Conserve water and the energy used to heat it in recreational buildings by installing low-flow faucets and showerheads as well as sink and shower controllers that automatically shut off. In dorms and recreation facilities, use tankless water heaters instead of traditional tank-type water heaters.
Gray-water heat-recovery systems can save 50% to 60% of water-heating energy when installed in shower drains, resulting in short payback periods (especially in buildings with substantial hot water usage, such as rec 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.
Appliances and office equipment
When buying or replacing appliances like refrigerators, washers, dryers, and vending machines, look for ENERGY STAR–certified models that maintain higher levels of energy efficiency. See the ENERGY STAR Office Equipment page for ways to cut energy use from monitors, printers, scanners, copiers, fax machines, and power adapters.
High-efficiency kitchen equipment
Cooking equipment, coolers, and dishwashers are energy hogs in kitchens—high-efficiency cooking equipment can be 15% to 30% more energy-efficient than standard equipment. The benefits of purchasing an energy-efficient model go beyond energy savings. The same measures that make the units more efficient can also lead to better performance. For a list of ENERGY STAR–qualified products and an online calculator that can help you determine savings for your particular upgrade, visit the ENERGY STAR Commercial Food Service Equipment page.
Boiler retrofit projects can provide substantial savings. Newer boilers feature a variety of efficiency improvements that 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 allows staged operation of each unit at its highest efficiency. Grouping boilers also provides redundancy. If a larger boiler isn’t ready to be retired, you can add a smaller boiler 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 lessens, causing drops in air pressure. More energy is then required to push air through the filter. Choosing filters rated for the lowest-possible pressure drop will cost more up front, but it 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, it will last longer and use less energy. For more information, see the air filtration section of A Design Guide for Energy-Efficient Research Laboratories by LBNL.
Life-cycle costs for equipment procurement
Identify who’s 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 energy costs and life-cycle costs in the procurement rules.
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