Air conditioners, Building automation systems (BASs), CFLs, Chillers, Commissioning, Daylighting, Elevators and escalators, Exterior lighting, Hospitals, Laundry appliances, LEDs, Lighting controls, Metal halide lighting, Monitoring-based commissioning, Municipal and healthcare facilities, Plug loads, Retrocommissioning, Windows
Each day, hospitals serve thousands of employees, patients, and visitors while being open 24/7. This naturally results in high energy use, making hospitals excellent targets for energy-efficiency measures. An average US hospital uses 31.0 kilowatt-hours (kWh) of electricity and 103,600 Btu of natural gas per square foot annually. In a typical hospital, lighting, space heating, and water heating represent about 65% of total energy use (Figure 1), making those systems the best targets for energy savings. By increasing energy efficiency, hospitals can improve the bottom line, freeing up funds to invest in new technologies and improve patient care.
Average energy use data
To better manage your building’s energy costs, it helps to understand how you are charged for those costs. Most utilities charge commercial buildings for natural gas based on the amount of energy delivered. Electricity, on the other hand, can be charged based on two measures: consumption and demand (Figure 2). The consumption component of your bill is based on the amount of electricity, in kWh, that the building consumes during a month. The demand component is the peak demand, in kilowatts (kW), occurring within the month or, for some utilities, during the previous 12 months. Demand charges can range from a few dollars per kW-month to upwards of $20 per kW-month. Because it can be a considerable percentage of your bill, you should take care to reduce peak demand whenever possible. As you consider the following energy cost-management recommendations, keep in mind how each one will affect both your consumption and demand.
Many hospitals have tight facility budgets, so low- or no-cost reductions in energy expenditures are especially important.
Turning things off
Although these may seem like simple measures to take, remember that every 1,000 kWh that you save by turning things off equals US$120 off your utility bill (assuming average electricity costs of $0.12/kWh).
Lighting In a typical healthcare facility in the US, lighting represents 16.2% of electricity consumption, not including its impact on cooling loads. Train staff to turn off lights in unoccupied rooms. Posting “Please turn the lights off when not needed” stickers above light switches will remind both staff and visitors to do so. Another option is delamping where illumination is excessive.
Office equipment Desktop computers can use more than twice the energy used by a flat-screen monitor, so it is important to sleep or power down computers that are not in use. The Energy Star Low Carbon IT Campaign provides ways to reduce IT costs, including free software that automatically places active monitors and computers into a low-power sleep mode through a local area network. Smart power strips with built-in occupancy sensors are available to shut off plugged-in devices like printers and monitors when there are no users present. Many of these strips power down devices that aren’t needed while continuing to provide power to devices that must have power all the time.
Kitchen appliances Where possible, only have kitchen equipment turned on when it’s in use. Good habits such as preheating ovens no more than 15 minutes prior to use and using fan hoods only while cooking can reduce energy use in kitchens.
Air-handling units There may be large fan systems serving areas unoccupied at night. In cafeterias, educational spaces, or offices, these units can be shut off during unoccupied hours.
Turning things down
Some equipment cannot be turned off entirely, but turning it down to minimum levels where possible can save energy.
Lighting controls Automatic lighting controls such as occupancy sensors, timers, photosensors, and dimmers save energy and help reduce maintenance costs. Rooms that are used only periodically, such as offices, break rooms, storage rooms, and restrooms, can produce significant energy savings when equipped with occupancy sensors and timers. For staff desks, a combination of occupancy sensors and time switches can accommodate people who arrive early or stay late. A recommended strategy for hallways is to use a combination of scheduled lighting and dimming plus occupancy sensors after-hours. In addition, dimmers and switches can be used to control light levels in areas receiving natural light. A study of 10 healthcare facilities in New York State found that lighting controls paid for themselves in an average of 1.2 years.
Operating-room air-handling setbacks Many operating rooms have air-handling units that draw 100% of their supply from outside air, which needs to be heated or cooled depending on the season. Occupancy sensors or manual switches can be installed in these rooms that will reduce the operating speed of the supply and exhaust fans when the rooms are unoccupied.
HVAC operation and maintenance
Regularly scheduled maintenance and periodic tune-ups save energy and extend the useful life of HVAC equipment. Create a preventive maintenance plan for your hospital that includes regularly scheduled tasks such as cleaning, calibration, component replacement, and general inspections. Ensure that information on setpoints and operating schedules is readily available for reference when equipment is checked or recalibrated.
Check and use controls Ensure thermostats are set correctly so different parts of the building are at the appropriate temperatures at the appropriate times. Use HVAC controls to reduce ventilation in areas when they’re not in use. This can be especially useful in operating rooms because they have very specific and essential needs that must be met during surgeries but are not required at other times.
Check the economizer Economizers are used in many air-conditioning systems to save energy. When the air outside is cool enough, the economizer draws in cool outside air to reduce the need for mechanically cooled air. The economizer uses input from various sensors to decide when to let outside air in and how much to let in. If not regularly checked, the linkage on an economizer damper can seize or break. An economizer stuck in the fully opened position can dramatically inflate a building’s energy bill by allowing in hot air during the cooling season and cold air during the heating season. About once each year, have a licensed technician check, clean, and lubricate your economizer’s linkage, calibrate the controls, and make repairs if necessary.
Follow a steam trap inspection and maintenance plan Steam traps remove water from the steam distribution system once it has cooled and condensed in a radiator or other heat exchanger. This configuration saves energy because it means all steam will release its heat to warm air before being cycled back into the boiler. However, mechanical steam traps can become stuck open, which wastes heat since live steam is being released. They can also become stuck in the closed position, which leads to a buildup of condensate that can cause significant damage to the system (this type of failure is less common and more easily diagnosed than when traps are stuck open). According to a US Department of Energy (DOE) Advanced Manufacturing Office Steam Tip Sheet (PDF), without maintenance, 15% to 30% of the installed steam traps in a steam system may fail within 3 to 5 years. This is significant because a single failed trap can waste more than $50 per month, and a hospital can have hundreds or even thousands of steam traps. Oversizing steam traps can cause the traps to work too hard, which can lead to blowing of live steam. Dirt accumulation can also plug up valves or cause them to get stuck open, releasing live steam. To actively monitor steam traps and get notified when they fail, steam trap monitors can be installed. Each one can monitor up to 16 steam traps to identify leaks. This can be especially important since one steam trap failing can lead to the failure of other steam traps draining into the same line. There are some general warning signs that steam traps may be failing:
- The boiler room is unusually hot.
- The condensate receiver is venting abnormally large amounts of steam.
- Water seals on condensate pumps are failing quickly.
- It is hard to maintain the boiler operating pressure.
- Maintaining the low pressure in return lines is difficult.
- Water hammer occurs—this is when slugs of condensate accelerate quickly in the pipes until stopped suddenly, which can damage equipment and cause pipes to collapse.
Maintain chillers Cleaning the chiller’s coils can greatly increase chiller efficiency. If the coils are dirty, the heat-transfer efficiency will decrease, significantly decreasing the efficiency of the unit. For a 10-ton unit, a $50 cleaning will typically pay for itself in two months and yield an additional $200 in savings over the course of the year. To see if a chiller could benefit, check the temperature difference between return and supply chiller water. This should generally be about 10° to 15° Fahrenheit (F). If the difference is much lower, it’s likely due to low efficiency and indicates the system could likely benefit from cleaning and maintenance.
Sequence chillers Operators often run more chillers than necessary for a given load. Because every chiller has a range of loading conditions wherein it operates most efficiently, turn chillers off to keep the remaining operating ones in their most efficient zone—typically, above the 30% to 50% loading mark. Chillers are far less efficient when operating below 30% of full load. As cooling loads increase, bring additional chillers online when the others are leaving their most efficient loading zone. If one chiller is significantly smaller than the rest (often referred to as the “swing” chiller), it can be brought on- and off-line first to keep the larger chillers more fully loaded. More chillers should not be turned on until the chillers currently running are at full load.
Operate multiple cooling towers to save fan power While it’s advantageous to run as few chillers as possible, it’s also advantageous to run as many cooling towers as possible. Most chilled-water plants have excess capacity, so that one or more cooling towers aren’t operating during low-load hours. To make the most of existing cooling towers, simply run condenser water over as many towers as possible, at the lowest possible fan speed, and as often as possible. This way, fan motors use less energy to cool the water. If two cooling towers run at half speed (instead of one at full speed), together they would reject slightly more heat than the single-tower operation while drawing only half the power.
Maintain cooling towers A dirty or corroded cooling tower is often the root of inefficiencies in these systems. To avoid this, cooling towers should be cleaned and maintained annually.
Check air-conditioning temperatures With 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 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.
Increase filter efficiency Filters should be changed on a monthly basis; they should be changed more often than this if you are located next to a highway or construction site where the air is much dirtier. Having clean filters can greatly increase HVAC efficiency. Increasing the cross-sectional area of filters can lead to more energy-efficient filtration. This can be achieved by using angled or pleated filters.
Check cabinet panels and clean condenser coils On a quarterly basis, do a maintenance check on your rooftop air-conditioning unit: Make sure the panels are fully attached with all screws in place, and also check to see that gaskets are intact so no air leaks out of the cabinet. If chilled air leaks out, it can cost $100 per year in wasted energy per rooftop unit. In addition, check condenser coils quarterly for debris, natural or otherwise, that can collect there. Thoroughly wash the coils at the beginning or end of the cooling season.
Check for airflow Hold your hand up to air registers to ensure that there is adequate airflow. If there is little airflow or if you find dirt and dust at the register, have a technician inspect your unit and ductwork.
Control blowdown Blowdown is used to remove solids from water in the boiler. This is necessary because solids will fall and form sludge at the bottom of the boiler, which lowers the boiler’s ability to transfer heat. Dissolved solids lead to foaming and carryover of boiler water into steam. So, blowdown is necessary at both the bottom and on the surface of the liquid. However, too much blowdown is wasteful and unnecessary. Installing a blowdown control system can help ensure that the best amount of surface blowdown is being used by monitoring the amount of water discharged in relation to the amount of dissolved solids present.
Avoid excess combustion air According to the DOE Building Technologies Program, decreasing excess combustion air by 15% will lead to a 1% increase in boiler efficiency (see Efficient Hospital Boilers Result in Financial, Environmental, and Safety Payoffs [PDF]). Tune combustion air to reduce excess air and to decrease accumulations in the air that lower combustion efficiency.
Decrease water impurities Treat water before it enters the boiler since impurities in the water can lead to up to a 12% decrease in boiler efficiency. Chemical treatments, clarifiers, and filters can be used to remove impurities. Additionally, water can be treated once it’s in the boiler to avoid buildup of impurities on boiler surfaces and decrease foaming.
Hospital kitchens feature a variety of energy-using equipment, and 11% of a hospital’s energy consumption is used for cooking (see also Improving Energy Efficiency in Commercial Kitchens).
Keep equipment clean Cleaning equipment can help it operate more efficiently and extend its life. For example, sediment in the bottom of a fryer can reduce its efficiency, and debris at the bottom of an oven can prevent the door from sealing well.
Check oven and steamer seals To keep heat from escaping, it’s important to make sure the seals around oven and steamer doors are in good shape and create a proper seal. If not, you may need to replace the seals.
Turn off unused equipment Running equipment that’s not in use wastes a significant amount of energy in commercial kitchens. Not only does the equipment itself tend to be inefficient, but it’s often turned on as soon as the workday commences—and it remains on until long after the last meal has been prepared.
Although the actions covered in this section require more time and investment, they can dramatically increase the efficiency of your facility without compromising patient care or comfort.
There are usually four steps to implement longer-term solutions. Before looking into these solutions, the hospital should analyze energy use so it is understood where energy is being used and where the hospital can save the most energy. Then, before any solutions are implemented, it should be understood exactly how they will benefit the hospital. The next step is the installation of the equipment. Finally, it is essential to continue maintenance of the equipment and ensure it continues to function as efficiently as possible.
Additionally, whenever faced with major equipment replacement, consider the full life-cycle costs, including maintenance and energy. Because hospitals tend to occupy the same facility for decades, considering life-cycle costs can help you to save money in the long run.
Commissioning strategies is a technical procedure that encompasses building inspection and systems testing to ensure facility performance according to equipment specifications and the owner’s expectations. Commissioning can increase a hospital’s efficiency, which decreases operational costs and increases equipment lifetime. Additionally, not only can commissioning uncover problems currently occurring, it can also help the hospital take preventative measures to avoid future problems. When commissioning is applied to an existing building that hasn’t been commissioned before, it’s called retrocommissioning. Hospitals can be excellent candidates for retrocommissioning because they tend to be energy-intensive, have long operating hours, require large amounts of outside air, and may use old equipment. Moreover, many hospitals have acquired new wings over the years without the benefit of a commissioning study or even recalibration of their building automation systems (BASs).
The majority of problems identified by commissioning tend to concern HVAC systems—in particular, air-distribution systems. Hospitals can benefit substantially from commissioning and retrocommissioning. A 2009 study by Lawrence Berkeley National Laboratory found that 75% of retrocommissioning projects had a payback period of 2.4 years or less. If your building was previously commissioned, consider investing in recommissioning every three to five years.
Hospitals can also perform ongoing monitoring-based commissioning, which uses sensors and software in addition to standard commissioning practices to provide a real-time account of systems within a building. This way, when large problems occur or things break, they can be fixed immediately rather than having the problem go undetected until recommissioning takes place. It also provides more persistent energy savings than conventional commissioning. Spaces should always be recommissioned when their use changes. As part of your contract, require your commissioning agent to provide instructions and documentation that can be used for future staff training and maintenance checklists.
Building automation systems
Approximately 73% of healthcare sector floor space is controlled with a BAS, also known as an energy management system. This system can control the HVAC, lighting, security, and other systems from one central location. This can increase efficiency and allow for easier monitoring of these various systems. By monitoring things like occupancy, temperature, lighting, and pressure, the BAS can run the different systems only when they’re needed and with minimal energy when they are running. Hospitals often have older, pneumatic-control systems that can be recalibrated or replaced with electronic systems. These newer systems are able to save much more energy than the older systems in place in many hospitals. BASs can also be useful for continuous monitoring and commissioning. In that case, data analysis software or a third-party diagnostic service can help identify operational anomalies. A BAS saves energy by:
- Only running systems when they’re required, by deciding which equipment needs to be running where and when based on a schedule of when and where the building is generally occupied and the weather
- Ensuring that the different systems within the building are running at minimum capacity
- Decreasing peak demand by reducing power to certain systems, like lighting, when the power draw of a building reaches a set number (with minimal impact on occupant comfort)
BASs are very effective in hospitals due to the large amount of energy hospitals consume and the specific needs of different rooms. BASs must be commissioned and operated properly for full energy-saving benefits to be realized.
Installing energy-efficient lighting has the potential to cut energy costs while improving satisfaction and performance among patients and staff. Hospital lighting retrofit projects can have an average payback of less than 1.9 years, according to a study of 10 hospitals in New York.
LEDs LEDs are well on their way toward becoming an effective option for a growing variety of uses, including replacing incandescent lamps, parking lot lighting, recessed downlighting, ambient lighting in offices, and many high-bay applications. Despite technological advances, successful application of LEDs still requires care in selecting products that will meet specific illumination needs, match manufacturer claims, and be compatible with any controls that are employed. In a 2014 case study, a hospital replaced 1,262 CFLs with LEDs that were compatible with the existing sockets and ballasts. According to Next Generation Luminaire (NGL) Downlight Demonstration Project: St. Anthony Hospital (PDF), this decreased total annual energy use by 59%. The estimated energy savings were 131,279 kWh per year, translating to annual savings of $15,193 at $0.12/kWh.
LEDs require less maintenance than most other light sources as they boast a life ranging from 25,000 hours to more than 100,000 hours, depending on the application. The competition ranges from 1,000 hours for incandescent lamps to as much as 70,000 hours for induction lighting. For conventional lamps, such as incandescent, fluorescent, or high-intensity discharge (HID) lamps, life is defined as the hours of operation after which half of a representative sample of lamps can be expected to fail. In contrast, LEDs don’t generally fail outright, rather, their output declines over time—so the industry generally defines LED life as the point at which the light output has declined to 70% of its original value.
Fluorescent lamps If your facility uses T12 fluorescent lamps or commodity-grade T8 lamps, relamping with high-performance T8 lamps and electronic ballasts can reduce lighting energy consumption by 35% or more. Adding specular reflectors, new lenses, and occupancy sensors or timers can double the savings. Paybacks of 1 to 3 years are common. LEDs, in the form of replacement tubes, retrofit kits, or new fixtures, have also become a viable option, offering considerable savings even compared to the best fluorescent options.
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 HID sources—including metal halide and high-pressure sodium lamps. 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 HIDs. But the best choice in most outdoor applications is LEDs—they can reduce light pollution and light trespass while offering high efficiency and long life. LED fixtures can be expensive, but costs are decreasing and performance continues to improve. LEDs also work better than other light sources with dimming and occupancy-sensing controls, which can lead to increased energy savings in parking lots.
Security lighting Using occupancy sensors with outdoor security lighting can save energy and improve security.
Daylighting A design strategy that uses a mix of both natural and electric light sources increases comfort and reduces energy costs. Appropriate window shading and separate shades on high windows are relatively low-cost retrofit options to increase daylighting. Light pipes and skylights can bring sunlight into interior spaces on top floors. Dimming ballasts and daylighting controls can be used to reduce the amount of electric light used when daylight is present. Natural light also provides other benefits besides energy savings. Patients in rooms with more natural light recover faster, and staff in hospitals with more daylight have higher productivity and job satisfaction. Additionally, with more daylighting, the hospital will rely less on electric lighting and can divert more energy to critical equipment during a power outage.
LED signage Installing LEDs in exit signs can decrease energy and maintenance costs as well as increase safety, as LED exit signs are brighter than conventional signs.
Autoclaves are used to sterilize equipment (usually surgical instruments) with hot steam at high pressure. Due to the high pressure, they require steam to be at higher temperatures than do most other steam appliances found in hospitals. By installing steam temperature boosters for autoclaves or spot steam generators that serve only autoclaves, the facility can reduce the temperature of the steam generated at the central plant and thus reduce energy costs. Autoclaves are also good candidates for heat recovery. The heat from the waste water or steam used in autoclaves can, using heat exchangers, be used to preheat water for autoclaves or boilers.
Cogeneration and other sources of heat recovery
Cogeneration systems provide both heat (for space or water heating) and power. Known as combined heat and power (CHP) systems, they have more applications and offer more savings potential for hospitals than for any other class of commercial building. CHP systems are particularly useful to hospitals because they can provide critical power when the grid is down. Though CHP systems cannot replace the need for backup generators (they’re required by law), CHP can still provide a reliable source of power and heat. Backup generators are more likely to have problems when they’re needed because they’re not used often and not always as well maintained. CHP systems are much better maintained because they’re in daily use. Additionally, backup generators take a few seconds to start up after a grid failure, whereas CHP systems will already have been running.
Some hospitals are installing advanced incineration systems to destroy medical waste. Capturing and using the waste heat from incinerators can be cost-effective in some cases. The University of Michigan saved $400,000 in annual steam bills by coupling medical waste incinerators with cogeneration.
Laundry and kitchen equipment as well as showers, boilers, and autoclaves can benefit from heat-recovery systems, which can be added as a retrofit. Waste heat from boiler exhaust stacks can also be effectively recovered and used to preheat boiler makeup water.
HVAC systems account for a large fraction of hospital electricity and natural gas consumption. Opportunities for savings exist in a wide range of Heating & cooling, Ventilation & air handling, and Heating & cooling equipment.
Use efficient boilers Condensing boilers achieve high efficiency by capturing additional heat released from condensing flue gas. Although more expensive, a condensing boiler has an average simple payback period of 5 years, with a 20% return on investment. The energy performance of existing boilers can be enhanced with stack gas heat recovery (also known as condensing heat exchangers), air preheaters, water recovery equipment, outdoor temperature controls, and pipe insulation. When replacing boilers, ensure they’re the proper size for the load required by the hospital—which could have changed significantly since the last boiler was installed. It can be beneficial to install multiple smaller units. Since boilers are more efficient when operating at a higher capacity, this approach allows more, smaller boilers to be operating more efficiently instead of one large boiler operating inefficiently.
Install adjustable-speed drives (ASDs) ASDs can be added to pumps and fans in HVAC systems, saving energy by allowing motors to adjust their output to fluctuating heating, cooling, and ventilation needs. Installing ASDs saves the most energy in spaces with lower ventilation requirements and can decrease power used by fans by up to 50%. Further savings are possible by using energy-recovery equipment, demand-controlled ventilation, and efficient fan motors.
Use demand-controlled ventilation Equipment can adjust the outside air ventilation depending on the occupancy and ventilation needs of the space. Occupancy can be determined a few different ways, with carbon dioxide (CO2) sensors being the most common. Areas with dense and sporadic occupancy patterns, such as lobbies or cafeterias, may be appropriate for demand-controlled ventilation using CO2 sensors. Occupant counting, such as ticket sales or video recognition, can also be used to estimate occupancy levels and determine ventilation needs. Occupancy sensors is another method, but it cannot differentiate between one person and full occupancy. Because of this, areas with fairly consistent and less dense occupancy levels, like offices, are good candidates for controlled ventilation using occupancy sensors. Finally, if fluctuation in occupancy can be predicted, such as in classrooms, ventilation can be scheduled with the BAS. All of these methods attempt to eliminate unnecessary ventilation and thus save energy without decreasing comfort.
Choose appropriate size fan Install fans that are the right size for the application so they’ll operate most efficiently. A whole-building analysis helps to ensure that fans are properly sized. Though this analysis may add to the cost of a project, the cost of a smaller fan will be lower, and the cost of operation will be decreased.
Install displacement ventilation systems Displacement ventilation can decrease energy use and reduce the likelihood that germs will spread. Cool air is supplied near the floor, and when it comes into contact with occupants, it absorbs the heat. This warm, contaminated air rises to the ceiling and is taken out of the room at the ceiling exhaust. Displacement ventilation only works for cooling, so a separate heating system is required. Ceiling heights should be at least 9 feet for this measure to be effective.
Install a coil bypass Adding a coil bypass to the heating and cooling coils can be useful. When the heating and cooling coils do not need to be in use, the bypass damper can open, allowing air to pass through the bypass with a much lower pressure drop. This saves fan energy. Since the installation of the coil bypass and controls can be expensive, this measure only makes sense for hospitals in climates where heating and cooling are often unnecessary.
Replace old chillers and boilers with efficient models When heating and cooling equipment is nearing the end of its life, there is an opportunity to install efficient and variable-capacity chillers and boilers. These replacements can offer considerable savings.
Use efficient auxiliary equipment Chilled-water systems are custom designed for each application, and employing efficient auxiliary equipment, like efficient pumps, valves, controls, and operating strategies, can often have a bigger impact than selecting an efficient chiller. Annual energy costs of a chiller can amount to one-third of its purchase price. In descending order, the most efficient chiller compressors are generally centrifugal, screw, scroll, and reciprocating.
Install water-side economizers A water-side economizer evaporatively cools water in a cooling tower and delivers it to a building’s chilled water coils via a flat-plate heat exchanger. In northern climates, the opportunity for free cooling with a water-side economizer typically exceeds 75% of the total annual operating hours, whereas in southern climates, such free cooling may only be available during 20% of operating hours. Typical simple payback periods from energy savings range from 2 to 5 years.
Install Energy Star equipment Look for Energy Star–qualified commercial food service equipment when making new purchases. Dishwashers, fryers, griddles, hot food holding cabinets, ice machines, ovens, refrigerators, freezers, and steam cookers are now available in energy-efficient models which are often 15% to 30% more energy efficient than standard equipment.
Install new prewash sprayers in kitchens Prewash sprayers are used to remove food from dishes, utensils, pots, and pans before they are placed in a dishwasher. Although all new low-flow sprayers are currently required to limit flow rate to 1.6 gallons per minute (gpm), many existing sprayers use up to 5.0 gpm. Given the small initial cost of low-flow prerinse spray valves, the payback for this measure is typically less than two months.
For more information on increasing energy efficiency in the kitchen, see Cooking & refrigeration.
Install more efficient washers Use Energy Star washers to decrease energy and water used by washers. Energy Star washers are 37% more efficient than other washers and also generally have larger capacities so that fewer loads of laundry have to be done. Additionally, front-load washers are more efficient than top-load washers because they can vary the amount of water used with the size of the load. Choose washers with higher spin speeds to decrease the energy needed for drying. Install dryers with sensors that turn the dryer off when clothes are dry. Finally, train staff how to best use the washers and dryers to maximize efficiency.
Reduce laundering temperatures Hospital laundry is typically done in water at 160°F, but according to the Centers for Disease Control and Prevention (see “Laundry: Washing Infected Material”), hospital laundry can be safely washed at temperatures below 160°F. This is assuming the cleaning agents work in colder water and are used in the proper amounts.
Use ozone laundering Hospitals are one of the best candidates for ozone laundering because there’s a large quantity of laundry that is not too soiled, and disinfection is particularly important. Ozone is a cleaning and disinfecting agent. It is injected into the water entering the washing machine where it breaks down soil molecules and destroys bacteria. Ozone breaks down soil molecules better than traditional cleaning agents, like chlorine. Ozone laundering uses cold water rather than hot water because ozone lasts longer in cold water. Using ozone laundering also decreases washing and drying times, so the motors in the appliances have to run for less time. According to PG&E’s Energy Solutions for Ozonated Laundry Systems in Hospitality Facilities (PDF), on average, ozone laundry systems (including washing and drying) save 8,651 kWh annually, or 3.5%. Additionally, ozone laundering decreases water and detergent use because detergent and rinsing are generally not necessary unless the laundry is particularly soiled.
Use CO2 laundering CO2 laundering uses CO2 instead of water. CO2 is used in the machine at high pressure when it’s a viscous liquid to clean the dirty laundry. Then, the pressure is reduced and the CO2 turns back into a gas, so there’s no drying necessary. The CO2 is removed from the machine and then filtered and distilled after each load to be used again. CO2 washers save water and energy in addition to having shorter washing cycles and increasing garment life, since there’s less heat and agitation. CO2 laundering is appropriate for hospitals because it provides absolute disinfection.
Hospital plug loads and efficient medical equipment
Nonmedical equipment There are ways to reduce nonmedical plug loads in different parts of hospitals (office, kitchen, and laundry), as described here.
Medical equipment Although there is not a lot of medical equipment available with an emphasis on energy efficiency, there are a number of developments in progress, including rating systems for the efficiency of medical equipment. Medical imaging equipment represents a good source of increased efficiency because it draws a lot of power when not in use and is in use only in short bursts. The Magnetom Amira from Siemens is an energy-saving magnetic resonance imaging scanner that is currently available. This machine saves energy by switching into standby mode when not in use. Energy Star is also coming out with ratings for medical imaging machines with different modes that will decrease power draw when the machines are not actively being used. The Appliance Standards Awareness Project is also a good way to stay up to date with standards and developments with medical equipment.
Solar Since hospitals are typically large facilities, they may be good candidates for solar photovoltaic (PV) power. There are many things to consider when installing PV, including mounting, positioning, tracking, shading, and weather. If roof space is limited, parking lot canopy PV systems can be a good choice. PV systems in parking lots also have other benefits, such as providing a very visible commitment to the environment; and they provide shade and shelter for parked cars. If the hospital owns empty or unused land, that can be another good option for installing PV, as it makes good use of otherwise unused land and often has a larger capacity than rooftops. For more information on PV and financing options, see On-Site Commercial Solar PV Decision Guide—For the Healthcare Sector (PDF) from the DOE.
Windows Windows provide daylight and views, but they also affect heating and cooling loads. Your particular climate will have a large effect on what’s best for your hospital. If cooling loads are dominant, glazing that transmits adequate light for daylight activity while minimizing solar heat transmission is best. In buildings where heating is the major HVAC load, glazing should be carefully chosen to minimize heat loss and, in some cases, configured to increase passive solar heat gain while maximizing daylighting. For more information on windows, see Building structure & automation.
Cool roofs Eliminating heat gain through the exterior roof and walls can be a cost-effective and low-risk way to reduce cooling loads and peak demand. One of the most effective measures is using light-colored roofs. See Cool Roofs to determine if they may make sense for your hospital.
Improved insulation Insulating exterior walls and roofs can have a big influence on room comfort and energy costs in older facilities. Nearly 40% of hospitals are improving the insulation in their buildings. Also, check insulation on ducts and pipes as well as hot water tanks. Replace or repair damaged insulation.
Elevators Energy use can be reduced by installing more efficient elevators, though this usually results in long payback periods if installed for the energy savings alone. There are other benefits to efficient elevators, though, such as high performance and improved reliability.
Vending machine controls Consider upgrading to Energy Star–qualified vending machines. This can reduce energy use by up to 50% (depending on the age of the machine), producing annual savings of around $150. Energy Star vending machines also come with software that can put the vending machine into low-energy lighting and refrigeration modes when the area is unoccupied, which can cut energy use by up to another 20%.
Office equipment Use Energy Star office equipment such as monitors, printers, scanners, copiers, fax machines, and power adaptors. Replace cathode-ray tube monitors with liquid crystal display monitors.
All content copyright © 1986-2020 E Source Companies LLC. All rights reserved.