Appliances and Equipment

Office equipment, food service equipment, and laundry equipment provide excellent opportunities for reducing energy consumption in commercial buildings. Efficient use of smaller, miscellaneous appliances can also help lower energy bills.

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Office Equipment

Office equipment is the fastest-growing use of electricity in commercial buildings in the United States, accounting for 7 percent of all commercial-sector power consumption. $1.8 billion is spent each year to operate office equipment in businesses and homes. ENERGY STAR^® office equipment is widely available and provides users with dramatic savings, as much as 90 percent in some product areas. Thousands of office products bear the ENERGY STAR label. Along with saving energy directly, this equipment can reduce air conditioning loads, noise from fans and transformers, and electromagnetic field emissions from monitors.

Selecting energy-efficient office equipment—personal computers (PCs), monitors, copiers, printers, and fax machines—and turning off machines when not in use can result in enormous energy savings. A typical PC operating 9 hours a day will use only 38 percent of the power consumed by a computer operating 24 hours. Even shutting off a computer for one-hour lunch breaks saves energy and will not affect the long-term performance of the equipment. Power management devices on computers can reduce energy usage even further by turning down the power when the computer is not in use. Copiers, laser printers, fax machines, and other office equipment can save up to 66 percent of their 24-hour power consumption if on only during office hours.

Computers

To save energy used by computers and monitors, buy ENERGY STAR-listed equipment or consider laptop computers. ENERGY STAR computers must have a power-saving mode that powers down to no more than 15 percent of maximum power usage. ENERGY STAR monitors power down to 15 watts or less after 15 to 30 minutes of inactivity, and then down to 8 watts or less after about 70 minutes of inactivity. Laptop computers save even more energy than ENERGY STAR-rated desktop computers/ monitors. Laptops draw only 15 to 25 watts during use, compared to the 150 watts used by a conventional PC and monitor, and their sleep mode typically uses just a fraction of a watt. To maximize savings with a laptop, put the AC adapter on a power strip that can be turned off (or will turn off automatically); the transformer in the AC adapter draws power continuously, even when the laptop is not plugged into the adapter.

ENERGY STAR computers and monitors save energy only when the energy management features are activated. ENERGY STAR products are shipped with energy-saving features activated. Employees should be able to adjust the energy-saving features to suit their particular needs and work habits (e.g., the length of time before power-down), but discouraged from deactivating those features.

The monitors must be capable of entering a low-power state. Monitors must be capable of being shut off by a Display Power Monitoring Signal (DPMS) signaling protocol, by a software utility, or by a special plug connected to the PC. "Universal" monitors can both accept a DPMS from a PC and run power management from a non-DPMS PC.

There is a common misconception that screen savers reduce energy use by monitors; they do not. Automatic switching to sleep mode or manually turning monitors off is always the better energy-saving strategy.

Miscellaneous Appliances

Miscellaneous devices that may significantly raise electricity use are those with long operating hours: refrigerators, coffee pots, heaters, water coolers and fans. Intermittent-use devices such as toaster ovens and hot plates may be of concern for building wiring or fire safety, but not for energy use. Coffee pots, because they are often left on all day, can use considerable energy. Offices should be encouraged to purchase thermos coffee dispensers, which not only save energy but result in better tasting coffee and less waste due to overheating. ENERGY STAR-rated water coolers are available that save energy while in standby mode.

Some individual fans and heaters found in offices are likely unnecessary, but when many are found in a building, it usually signals inadequacies in the space conditioning or ventilation system. If it is possible to get the system fixed, then managers can ask to have the fans and heaters removed. An energy conservation program should not take on such devices where working conditions are inadequate.

If there are many private-use refrigerators, this may be due to inadequate kitchen facilities, and increasing them may be appropriate.

Food Service Equipment

Food service equipment consumes much energy and water. New types of high-capacity, multistage dishwashing machines, high-efficiency refrigerators, and advanced cooking equipment provide significant opportunities to save resources and money. In each case, heat recovery systems can be used to capture waste energy from appliances and preheat air (for HVAC) or water.

Make energy efficiency and water efficiency key considerations when outfitting a new kitchen or laundry, as well as when renovating these spaces or replacing individual pieces of equipment. In certain situations, replacement will be justified solely on the basis of energy savings. Also consider measures to recover waste heat at the time of new equipment selection or kitchen renovation.

Dishwashers

Most of the energy used by dishwashers is to heat water. Therefore, an efficient dishwasher either uses less water to do the job or heats the water itself. Several high-efficiency European models are becoming more common on the American market, and domestic manufacturers are also making more efficient models.

New high-capacity, multistage dishwashing machines are designed for medium-to-large food service operations, including hospitals, colleges, hotels, and restaurants. In addition to reducing water usage and load requirements, labor requirements for operation are reduced by 50 percent.

Multistage dishwashers reuse water from the two rinse stages to prewash dishes. In addition to reducing water consumption, these devices save a considerable amount of detergent and rinse additives. Because of their improved design, dish breakage is also significantly reduced. Power scrapers are available for some dishwasher models that remove caked-on, dried food. This can be particularly useful when there is a significant time lag between use and washing. Typical throughput of dishes in a high-capacity, multistage washing machine is 3,500 to 3,700 dishes per hour, with a conveyor speed of 5 to 6 feet (1.5 to 1.8 m) per minute.

Look for the EnergyGuide label that tells how much electricity, in kilowatt-hours (kWh), the dishwasher will use in one year. The smaller the number, the less energy it uses. ENERGY STAR dishwashers exceed federal standards by at least 13 percent.

Refrigerators and Freezers

In commissaries, refrigerators and freezers can account for up to 50 percent of energy consumption. Energy efficiency advances in commercial refrigeration have paralleled those in residential refrigeration since the 1970s.

Refrigerators and freezers are divided into medium temperature (MT) systems, down to 20° F (-7° C), and low-temperature (LT) systems, down to -25° F (-32° C). New equipment is available with EERs of 7 to 9 for MT systems and 5 to 6 for LT systems. Replace old, inefficient systems with new, high-efficiency systems to obtain significant savings.

Relying on refrigerator cases to cool the interior of a space is not very useful, as HVAC systems typically have EERs of 10 to 12 versus the 5 to 9 for refrigeration equipment. This translates to a difference of 40 percent in energy use. Air spillage from the refrigeration equipment should be minimized.

Product literature specifies proper operation and maintenance of refrigerators and freezers. Some of the causes of excessive energy use by these devices are controls set too low, doors that do not close properly, and worn or torn gaskets. An accurate thermometer is needed to check temperature conditions. Cleaning condenser heat transfer surfaces to remove dirt and scale is very important for proper and efficient operation. Overloading the unit may result in over- or undercooling the stored food.

Cooking Equipment

The key strategies for saving energy when using cooking equipment are:

Turn equipment off when not in use.
Use a temperature no higher than necessary.
Match the equipment to the job.
Cook as efficiently as possible. This includes adjusting flames on ranges to just touch the bottom of cookware, avoiding unnecessary oven door openings, cooking foods with the same requirements simultaneously, and cooking in volume.

When upgrading a kitchen, consider the following energy-efficient types of equipment: infrared fryers, convection ovens (including steamer models), microwave ovens, and specialized equipment. Specialized equipment (such as a pizza oven) is designed to cook specific foods very efficiently. Computerized controls can also produce savings by automatically timing the cooking of certain foods.

Energy-efficient exhaust hoods can provide significant savings because they use outside air rather than inside conditioned air for ventilation. Side curtains around cooking equipment can help restrict the flow of conditioned air to the outside. Exhaust air also can be used to preheat air for HVAC purposes or to preheat water.

Laundry Equipment

Clothes Washers

Horizontal-axis (H-axis) washing machines, also called front loaders, are far more energy- and water-efficient than conventional top loading, vertical-axis machines. H-axis commercial equipment has been available for many years, but new products (based on residential models) have been introduced recently. One manufacturer has designed a resource-efficient vertical-axis residential washer that performs far better than typical toploaders and meets ENERGY STAR standards. Look for washing machines that meet ENERGY STAR requirements for water and energy savings.

Laundry water temperatures should be reduced to 160 degrees F (71 degrees C) unless prohibited by code. Some soaps and detergents perform well at lower temperatures and should be used where appropriate. Temperatures should be checked with an accurate thermometer, and equipment should be adjusted as needed. Microcomputers on newer-model clothes washing machines permit precise control of water temperature and cycles. Using equipment efficiently means ensuring that washing machines and dryers are operated with full loads rather than partial loads.

Large commercial laundries should consider water recycling and batch tunnel washers as water-conservation measures. Continuous-batch machines conserve water and energy, as do machines that recycle the final rinse for use as the first wash on the next batch. To reduce energy use by clothes washers, make sure that hot water heaters are operating efficiently: repair leaks, insulate storage tanks and distribution piping, clean sediment out of equipment, and test/tune-up water-heating components.

Clothes Dryers

Dryers work by heating and aerating clothes. Clothes dryer efficiency is measured by a term called the energy factor. It is somewhat similar to the miles per gallon for a car, but in this case the measure is pounds of clothing per kilowatt-hour of electricity. The minimum rating for a standard capacity electric dryer is 3.01. For gas dryers the minimum energy factor is 2.67. The rating for gas dryers is provided in kilowatt-hours though the primary source of fuel is natural gas.

Unlike most other types of appliances, energy consumption does not vary significantly among comparable models of clothes dryers. Clothes dryers are not required to display EnergyGuide labels.

Look for a clothes dryer with a moisture sensor that automatically shuts off the machine when the clothes are dry. Not only will this save energy, it will reduce the wear and tear on clothes from over-drying.

The best dryers have moisture sensors in the drum for sensing dryness, while most only infer dryness by sensing the temperature of the exhaust air. Compared with timed drying, savings of about 10 percent with a temperature sensing control, and 15 percent with a moisture sensing control are available.

Look for a dryer with a cycle that includes a cool-down period, sometimes known as a "perma-press" cycle. In the last few minutes of the cycle, cool air—rather than heated air—is blown through the tumbling clothes to complete the drying process.

Gas dryers are typically less expensive to operate than electric dryers.