Municipal Government Facilities
Air conditioners, Building automation systems (BASs), Commissioning, Daylighting, Electronics and office equipment, LEDs, Light sensing and switching, Lighting, Lighting controls, Municipal and healthcare facilities, Municipal government, Plug loads, Recommissioning, Retrocommissioning, Roofs, Rooftop units (RTUs), Smart thermostats
Municipal governments oversee large and small administrative buildings, libraries, indoor and outdoor recreation centers, K–12 schools, and wastewater treatment plants. They also manage streetlights, parking structure lights, and traffic signals.
Energy represents about 19% of total expenditures for the typical office building. Lighting, heating, and cooling are the biggest energy consumers, accounting for almost 70% of total energy use (figure 1). These systems are the best targets for energy savings.
Average energy-use data
As much as 40% of a municipality’s electric bill goes to streetlighting. Converting older lighting technologies to LEDs or other advanced technologies is one way to cut costs while keeping people safe on the streets and enhancing the nighttime ambiance.
Turning things off
Turning things off seems simple, but remember that for every 1,000 kilowatt-hours (kWh) you save by powering things off, you save $120 on your utility bill (assuming average electricity costs of $0.12 per kWh).
Computers and monitors In municipal buildings, computers and other electronic equipment consume about 20% of your overall energy. Enable computer power-management settings on individual computers and monitors to force them into sleep mode when they’re not in use. Effective power-management settings can cut a computer’s electricity use roughly in half, saving up to $75 annually per computer. Although most computers come with power-management settings enabled, you can make them more rigorous to maximize energy savings. For more information, the US Environmental Protection Agency (EPA) offers detailed instructions on ENERGY STAR’s Business Case for Power Management page. Don’t worry about automatic software updates being inhibited if power-management settings are enabled. They can automatically download when the computer wakes up from sleep mode.
Other office equipment and plug loads Printers, fax machines, and coffeemakers often have energy-reduction settings too. You can make these devices even more energy efficient by plugging them in to smart power strips with occupancy sensors. That way, your employees can switch off their personal devices—such as personal printers, monitors, desk lamps, radios, and clocks—with one click.
Lights People often forget to turn off lights after they leave a room. When properly installed, occupancy sensors and timers can turn lights off automatically when no one is in the area. You should also train staff to turn off lights as part of their closing procedures. Make sure they know where all the facility’s light switches are located.
Space heaters Space heaters are energy hogs, drawing 1 kilowatt (kW) or more of power. Your first step should be to check your HVAC control system to make sure shared and personal spaces are getting the right amount of heating and cooling. Second, plug heaters into power strips controlled by occupancy sensors.
Chilled-water drinking fountains and water coolers Unless it’s required for health reasons, water fountains don’t need to provide ice-cold water 24 hours a day. You can save energy by turning off fountain cooling systems. Similarly, you don’t need to keep water coolers on 24 hours a day. The average office water cooler consumes about 800 kWh per year, mostly when it’s in standby mode. You can cut energy waste by attaching a timer to the cooler that turns it on for only 10 hours a day, 5 days a week. When it’s time to replace old coolers, choose an ENERGY STAR–qualified model. They can give you more energy savings because they have thicker insulation, more-efficient cooling systems, and other efficiency-boosting features.
Vending machines Refrigerated vending machines typically operate 24-7, using 2,500 to 4,400 kWh per year and requiring HVAC systems to work harder to cool the spaces where vending machines are plugged in. Use timers or occupancy sensors so machines turn on only when someone is in the area or when the compressor needs to run to keep the products at the right temperature.
Turning things down
You can’t turn off all your equipment, but you can turn down some of it to save energy.
HVAC temperature setbacks When your facility is closed, turn temperature settings down in heating seasons and up in cooling seasons. Use programmable thermostats to do the work for you.
Peripheral and back rooms Keep HVAC settings in stockrooms and rarely used spaces at their minimum.
Window shades and blinds During warm weather, close your blinds to block direct sunlight and keep cool air in. In the winter, open the blinds on south-facing windows to let in sunlight that can help heat the space.
Building automation systems tuning In your office buildings that already have building automation systems (BASs), make sure you coordinate temperature setbacks with building occupancy every quarter. Adjust temperature settings in buildings that aren’t used at night, on weekends, or for long periods of time (such as during holiday breaks). Also check that HVAC systems aren’t set to overcool or overheat the building. For facilities with regular occupancy schedules but without a BAS, use programmable thermostats to keep temperatures stable.
HVAC cleaning and maintenance
Save energy and extend the useful life of your HVAC equipment by regularly inspecting, cleaning, calibrating, and replacing components. It’s also a good idea to have information on setpoints and operating schedules nearby when you’re checking equipment.
Check the economizer Many air-conditioning systems (other than those in hot and humid climates) use a vent called an economizer to draw cool air from the outside into the building. You should regularly check the economizer to make sure it’s not stuck in the fully open position. A wide-open economizer can add as much as 50% to a building’s annual energy bill by allowing hot air in during cooling season and cold air in during the heating season. About once a year, you should clean and lubricate the economizer.
Check air-conditioning temperatures Check the temperature of the air going into your air conditioner (AC) and the air coming out of the register that’s nearest the AC unit. If the temperature difference is less than 14° Fahrenheit (F) or more than 22°F, the refrigerant may be using more energy than necessary. Ask a licensed technician to regularly inspect your AC unit.
Change the filters Change your AC filters every one to six months, depending on the level of pollutants and dust in the indoor and outdoor air. You might have to change the filters more frequently if you’re using economizers because outdoor air is usually dirtier than indoor air.
Check the cabinet panels After you change the filters, check to see that the panels on your packaged rooftop air-conditioning unit are fully attached, with all screws and gaskets in place so no air is leaking out of the cabinet. Chilled-air leaks can cost $100 per rooftop unit per year in wasted energy.
Clean the condenser coils Once a quarter, check the dirt buildup on the condenser coils. At the beginning and end of the cooling season, thoroughly wash the coils.
Check the airflow
Hold your hand up to the registers to check airflow. If there’s little airflow or a lot of dirt and dust in the register, ask a technician to inspect your unit and ductwork.
Follow a steam-trap inspection and maintenance plan If your buildings have radiant steam heat, they have steam traps that remove water from the steam distribution system after it has cooled and condensed in radiators or other heat exchangers. Mechanical steam traps can get stuck open, which wastes heat. A single failed trap can waste more than $50 per month—and offices often have many steam traps within the building.
Encourage energy-saving behavior in the workplace Employers are setting up green teams, interactive energy-use kiosks, training classes, and energy competitions to encourage employees to save energy in the workplace. These efforts can help businesses cut their energy use by 2% to 10%.
Longer-term solutions require more capital investment and longer payback periods, but they often result in larger energy and cost savings. Before you take on a big energy project:
- Set a reduction goal. Get staff and your community on board with energy efficiency by setting a target. Sustainable Chicago 2015 initiative set a goal to reduce energy use in municipal buildings by 10%. Seattle is aiming to reduce energy use in city-owned building by 20% by 2020. Read more in the report City of Seattle Building Energy Performance and Carbon Emissions (PDF).
- Hire a shared energy manager. Take the load off busy facility managers by hiring an energy manager to monitor energy usage in buildings across your municipality.
When you commission a building, you ensure that its systems are designed, installed, functionally tested, and capable of supporting the owner’s operational needs. Commissioning can cut energy bills by 10% to 15% or more, and can pay for itself in less than one year. When you check and validate the systems of an existing building that hasn’t been commissioned before, it’s called retrocommissioning. When you do it for a building that has been commissioned before, it’s called recommissioning. When you leave monitoring equipment in place to run continuous diagnostics, it’s called ongoing commissioning. You should recommission a building every three to five years.
Building automation systems
Sometimes called energy management systems, BASs save between 5% and 15% of overall building energy consumption and can also improve occupant comfort. BASs can be complex and expensive, so they’re cost-effective only in buildings larger than 50,000 square feet (ft2). But older or poorly maintained buildings can benefit from a BAS retrofit, sometimes yielding savings of over 30%. To existing barebones BAS systems, you can add submeters and wireless controls to get information that can help you set baselines, benchmark, troubleshoot, identify areas for improvement, and evaluate performance. Recently, the cost of submeters and wireless controls has dropped, making them even more attractive tools for improving building performance.
Cloud thermostats have a lot of the functionality, analytic abilities, and energy-saving benefits of a BAS but at a much lower cost, making them a great choice for buildings less than 50,000 ft2. They’re also becoming more sophisticated and may soon provide a central control point for lighting, water heating, and plug loads.
Energy analytics software
You can use software to analyze energy use in single buildings and multiple-unit facilities. The software can identify problems such as malfunctioning or poorly tuned HVAC systems or whole buildings that are using more energy than their neighbors or other buildings your portfolio.
Indoor lighting measures
LED lighting LEDs are highly efficient and last a long time. They’re also getting cheaper, which means you can use them for everything from exit signs and task lighting to recessed downlighting and ambient lighting.
Troffers are rectangular light fixtures that are affixed to ceilings. Fluorescent troffers account for 50% of lights in commercial buildings. The best LED troffers outperform their fluorescent counterparts, but at a first-cost premium. You can replace fluorescent troffers with LED troffers via LED retrofit kits, or by replacing the fluorescent tubes with tubular LED products.
When you buy LED-based products, ask for performance data based on standard tests performed by accredited laboratories. And when you compare LEDs to other options, be sure your calculations include cost savings from reduced maintenance due to LEDs’ long lifetime. Finally, start with a small test case at one of your buildings to make sure your LED solution will provide the quantity and quality of light you need.
Fluorescent lamps If your buildings use T12 fluorescent lamps or commodity-grade T8 lamps, replace them with high-performance T8 lamps and electronic ballasts. This swap can reduce your lighting energy consumption by 35% or more. Adding specular reflectors, new lenses, and occupancy sensors or timers can double the savings. And your investment will pay off in one to three years.
Lighting controls Install a lighting control system to get the right amount of light where and when it’s needed. Depending on the baseline conditions and the strategies you use, a lighting control system will cut lighting energy use by 5% to 60%. It may also qualify you to participate in demand-response (DR) programs through your utility. DR programs reward you for using less energy at certain times of day and year. Advanced control systems can also tell you when lamps are burned out or failing.
Daylighting Take advantage of daylight when you can. Install dimming ballasts, or dimmable LED drivers, and daylighting controls to balance natural light with electric light.
Outdoor lighting optimization
It takes a lot of energy to light roadways, recreational areas, parking lots, public transportation depots, and other public spaces. You can’t turn off these lights because they’re essential for security, pedestrian and traffic safety, economic development, and aesthetics. But you have energy-efficiency options.
Reducing light levels Parking lots are often overlit—an average of 1 foot-candle of light or less is usually sufficient. Use dimming and occupancy-sensing controls to save energy in surface lots.
Installing more-efficient light sources Replace your metal halide and high-pressure sodium (HPS) lights and your fluorescent and induction lamps with LEDs.
For parking lots and streetlights, LED fixtures are a great choice because they perform well in cooler conditions, like nighttime. They also work better with controls than HPS and metal halide lamps do.
California State University, Sacramento field-tested bi-level LED lighting with occupancy sensing at a parking garage on the campus. The school saw energy savings of 78% between midnight and 6 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, note 24-hour energy savings of 68% compared to the old HPS lighting system.
Because LEDs work well with controls, several municipalities are networking their streetlights. Some are using these networks to support other functions such as traffic control and public safety. Read Greentech Media’s article Will Street Lights Become the Nodes of the Networked City? and the Northwest Energy Efficiency Alliance’s Technology and Market Assessment of Networked Outdoor Lighting Controls (PDF) reports to learn more.
LEDs also have long lifespans, which means you’ll spend less time rolling out bucket trucks to replace burned-out lamps. Plus, LEDs distribute light more directly and evenly, which means you’re not polluting nighttime skies or shining lights in people’s windows. These LED properties improve aesthetics and contribute to energy savings.
The US Department of Energy (DOE) Municipal Solid-State Street Lighting Consortium provides specifications, financing guidance and tools, and demonstration results. The DOE Better Buildings Alliance, on its Energy Efficient Lighting for Parking Facilities web page, provides more information, including a sample specification, some case studies, and information on the Lighting Energy Efficiency in Parking Campaign. The Alliance estimates that using LEDs can cut energy use by 40% or more, depending on the application.
High-efficiency HVAC units By replacing your standard-efficiency, commercial packaged air-conditioning/heating unit with a highly efficient packaged unit, you can reduce cooling energy consumption by 10% or more. Single-zone variable speed rooftop units (RTUs) can also cut your cooling energy usage. Choose equipment that has multiple levels of capacity—that is, compressor stages—so it runs efficiently at lower outputs.
Advanced RTU controllers Retrofit existing RTUs with advanced packaged controllers to improve functionality and save energy. Estimates and preliminary field-test results show that a retrofitted RTU can cut energy costs by 20% to over 50%, with a typical payback period of one to four years. Energy-saving features can include variable- or multispeed supply fan control, demand-controlled ventilation, and improved economizer control. Additional features can include DR, remote monitoring, and fault detection and diagnostics.
Demand-controlled ventilation If the number of people at your facility varies dramatically over the day, you can save energy by decreasing the amount of ventilation your HVAC system supplies during low-occupancy hours. A demand-controlled ventilation (DCV) system senses the level of carbon dioxide in the return airstream and, when levels are low, decreases supply air. DCV systems are particularly useful in auditoriums, meeting rooms, and cafeterias, where occupancy levels swing greatly.
Boiler retrofits Replace your old boilers. Newer boilers have efficiency improvements such as condensing heat exchangers, sealed combustion, electric ignition, and fan-assisted combustion that can justify replacing older boilers before they fail. Smaller boilers are more efficient than larger ones. By grouping multiple smaller boilers, you can stage each unit at its highest efficiency point and ensure 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.
Reflective building roof coating If you need to recoat or paint your facility’s roof, consider white or some other 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, visit the ENERGY STAR Roof Products web page.
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