Follow these guidelines to save your business money and energy.
Plants with wide variations in air demand need a system that operates efficiently under part-load. In such cases, multiple compressors with sequencing controls may provide a more economical operation option. Plants with a more consistent load profile are able to use more simple control strategies.
Replacing light switches with occupancy sensors in walk-in refrigerators and freezers can save nearly $200 a year in energy costs and reduce the load on the compressor.
Don't waste flash steam by venting into the atmosphere. Various industries use high- and medium-pressure steam containing valuable energy that can be recovered. Use that steam to preheat domestic hot water or returned hot water from the building’s heating system.
Utilizing high-efficiency compressor systems can result in significant energy savings–roughly 6 percent for ice machines and as much as 16 percent for reach-in freezers.
According to Emerson Network Power, properly designed supplemental cooling has been shown to reduce data center cooling energy costs by 35 to 50 percent compared to perimeter cooling only.
Examine seal outlets and gaps between moldings, as well as plumbing and wiring penetrations. Additional checkpoints include hatches, plumbing vents, chimneys and other roof or wall penetrations. Many areas can be sealed by caulking. Use foam sealants for larger areas.
Aluminum windows should have an insulating section — a thermal break — between the inner and outer aluminum sections of the frames. This basic feature reduces thermal conductivity of the metal to the same level as wood.
An energy audit helps you understand how your facility uses various forms of energy — including electricity, gas, and other utilities — and helps you identify waste or inefficiency. By identifying on-peak and off-peak periods, you can use information from audits to take advantage of various rate structures.
When constructing a new building or replacing older systems, consider installaling a variable speed drive chiller and/or geothermal heat pump. They operate up to 30 percent more efficiently than the industry average. Geothermal heat pumps may cost more to install than conventional HVAC equipment, but they cost less to operate than conventional HVAC systems.
Adding skylights allows for daylighting, which decreases energy use. Studies show that increased daylight also increases employee productivity.
Match the size of the job to the size of the equipment. Combi-ovens, turbo-ovens, and connectionless steamers can speed cooking times and save both water and energy. Match the pan size to the element size when using an electric cooktop. A six-inch pan on an eight-inch burner can waste up to 40 percent of the heat produced.
During evening hours, use candlelight in dining rooms. Not only does using candlelight increase a dining room’s ambiance, but it also saves your restaurant or food service facility money in energy costs. Use it when appropriate.
When practical, recover and reuse waste heat from air conditioning and refrigeration equipment. Waste heat capturing equipment includes hot gas desuperheaters, double-bundle condensers and auxiliary condensers.
Walk through the facility after operating hours to identify energy waste, check settings on equipment, establish a list of energy shut-down/off procedures and review your findings with plant managers and employees. Continue to inspect the plant, systems and equipment to ensure adherence to energy reducing procedures.
If your hotel staff is able to book rooms in clusters, you’ll increase the efficiency of your facility without compromising the hospitality experience.
Most motors operate at 75 percent of the horsepower rate shown on their accompanying nameplate. An oversized motor is often more efficient than a smaller motor operating at driving load.
According to Emerson Network Power, the top priority in any data center is to use precision cooling. Second is to optimize air flow. You can do this by arranging racks in a hot-aisle/cold-aisle configuration, by reducing air recirculation and by using ducts to return hot air to the cooling unit. Continually monitor your systems and conduct thermal assessments to make sure you stay on track.
Create a document that employees or occupants can reference for compliance and guidance around your organization’s energy management policy. Update the document as needed to reflect energy reduction wins and new policies or procedures.
Installing electric radiant heaters in areas frequented by employees or workers will keep occupants warm without excessive heat loss. Adding a timer or occupancy sensor to the heater will keep even a small area from being heated if there’s no one in it.
In the kitchen, code often requires higher water temperatures. However, setting water temps to 120° F outside the kitchen area will help reduce energy consumption and control expenses.
To reduce energy demand during periods of high-energy use, consider load shifting. Using a thermal energy storage system, capture off-peak electricity during periods of low-energy use and use that energy later, during periods of high energy demand.
Reducing pumping power in cooling systems can be accomplished by eliminating bypass valves and three-way valves; removing auto flow valves, pressure regulating valves and other flow restrictors, and opening balancing valves at the pump.
Reduce the amount of paving around a building by adding landscaping. This will help keep buildings cooler in the summer.
Using variable speeds on pumps, fans and compressors operating at various loads will reduce peak and off-peak energy costs.
A hot running motor is a sign of age or of an unhealthy motor. It also indicates inefficiency and/or below average performance. To assess the motor’s true efficiency, measure the motor’s actual output versus the current.
If your water pressure exceeds 40 to 50 psi, install a pressure-reducing valve and reduce energy costs. If gauges indicate your water pressure is too high, consider having a plumber install a pressure-reducing valve on the main service. This valve will restrict the amount of hot water that flows from a tap and reduce energy costs.
Energy-saving TLEDs make sense in larger, occupied spaces, but their output is unnecessary in closets and hallways. Use Energy Star certified LED lightbulbs to save money and energy. Also consider installing dimmers and/or timers that would reduce hallway light levels by up to 30% during daylight hours.
Many opportunities exist to reuse thermal energy within a building. For instance, rejected waste heat from air conditioning or refrigeration equipment can often be used to serve building needs. To capture waste heat, hot gas desuperheaters, double-bundle condensers and auxiliary condensers can be used on almost every type of air conditioning and refrigeration equipment.
Vending machine controls can be used to cycle refrigeration compressors on and off based on a predetermined temperature range. After hours or at times when a space is unoccupied, vending machine controls can turn off vending machine lighting, and turn it back on when motion is detected. If automatic controls are not an option, reduce or remove bulbs from machines that are lit unnecessarily.
Replacing your 10, or 20 watt incandescent lamps in your facility’s exit signs with Light Emitting Diode (LED)-powered signs leads to savings. LEDs are easier to maintain, last longer, and are less expensive than their incandescent and neon light counterparts. ENERGY STAR estimates an LED-powered exit sign costs $50 less per year to operate than an incandescent sign.
Save 3 to 5 percent of energy costs with a high-efficiency condenser fan motor.
To improve motor reliability and efficiency, www.energy.gov suggests you maintain the correct voltage and phase balance, identify and eliminate current leaks, and prevent harmonics in the electrical supply. The DOE also suggests having an electrical engineer review the electrical system. Conduct an inspection before installing a new motor or after you’ve made changes to your system or system loads.
Appropriate for offices, classrooms, and meeting or conference rooms, bi-level switching allows occupants to turn on a group of fixtures–such as half the lights or a third of the lights–when using all the lights is unnecessary. Work with housekeeping or custodial staff to ensure lights aren't left on needlessly. Develop an informal or even a formal monitoring plan, which can include incentives or rewards for turning lights off after hours. Consider making compliance part of housekeeping, contractors or staff performance measures.
A typical restaurant or food services facility will save up to $15,000 a year by outfitting its kitchen with energy-efficient or ENERGY STAR® qualified equipment.
Along with helping save up to 50 percent in energy costs, glass doors on multi-deck display cases reduce cold air spillage, keep compressors from working overtime and increase customer comfort.
In facilities such as congregations and schools, keep track of how meeting spaces and classrooms are used. Using appropriately sized meeting spaces for the number of occupants gathered will save you money on heating and/or cooling and lighting. Tracking meeting room usage will help you recognize patterns and help you identify how best to schedule gatherings and increase energy efficiency.
Calibrate pneumatic thermostats every 3-6 months to avoid loss of efficiency.
According to Liebert Services failure tracking, more than a third of all uninterruptible power supply (UPS) system failures are caused by battery related failures. Monitor and maintain your UPS and its batteries either via manual tests or via remote monitoring and management software.
Using electric forklifts will not only reduce emissions and make your operation greener, but it will also save you money on ventilation.
Consider controlling all the cooling tower fans with one variable frequency drive and modulate the fan speed together.
In areas with a moderate to warm climate, a heat pump system can do the job of a standard electric water heater while using half the electricity. Heat pumps also transfer heat from your facility’s interior into its water tank, reducing the load on your HVAC system.
Seemingly small cracks or holes in the building exterior (like walls, windows, doors, ceiling and floors) can add up to substantial heating or cooling losses. Install weather stripping and caulking to repair air leaks.
Do not overlook minor improvements to the HVAC mechanical system. These include installing flue dampers or balancing the ventilation system to reduce exhaust rate, relocating the thermostat and installing fans to keep hot air off the ceiling, and installing thermostats in hot water tanks.
To ensure heaters are working properly, check pool water temperatures regularly. A high-water temperature can indicate a heater that’s overheating the water. The National Swimming Pool Foundation recommends that the pool temperature be set between 78 and 84°F, depending on the pool’s usage. Covering a heated pool can save 50-70 percent in energy consumption. It can also reduce water loss and prevent the loss of 35-60 percent of the chemicals used to treat the water.
In plants with multiple cooling towers and chillers, facilitate heat transfer by running all the water over the tower fills rather than just a single tower.
Use occupancy sensors to turn lights on and off automatically in low-traffic spaces, including restrooms, break rooms, supply rooms and locker rooms.
One of the most cost-effective conservation measures available is to add roof insulation–including a vapor barrier–when you’re replacing a roof. For historic property or new construction, the cost of adding insulation results in a rapid payback.
If your lighting system uses energy magnetic ballasts and “watt miser” lamps, you could upgrade to a TLED system for further savings.
Use steam turbines to capture energy losses from pressure-reducing valves (PRVs). PRVs can be bypassed by back-pressure turbines, which exhaust steam at the same pressure as the PRV. For example, turbines can be used to drive a generator, pump, chiller or compressor. A back-pressure turbine operating at 250 psi supply and 15 psi exhaust, expanding 20,000 Btu of steam per hour, can drive a generator producing as much as 129 kw. If this turbine operates for 6,000 hours per year, the electricity produced could be worth as much as $40,000.
Whenever medium- or high-pressure steam boilers are used, there will be flash steam in the condensate system. This flash steam contains valuable energy that can be recovered. High- and medium-pressure steam is used in many types of structures, including hospitals, universities and industrial facilities. Good uses for the recovered heat are to preheat domestic hot water or to preheat returned hot water from the building’s heating system. Approximately 5 to 15 percent of returned condensate will flash to steam at approximately 5 psi. If this steam is vented to atmosphere, the heat is wasted.
Install motion-activated nightlights in bathrooms since customers often leave bathroom lights on. By providing a motion-activated light, you can reduce the need for full on lighting.
Every NEMA standard polyphase Design B motor below 150 hp (and many well above that) has an efficiency value stamped on its nameplate. That value is a “nominal” value that is representative of that particular design. For every such value, a “minimum,” or guaranteed value, is published in NEMA standards. For that reason, when comparing brands, it’s best to use NEMA’s ratings as a guide. While some motor lines may offer efficiencies far above the NEMA “energy efficient” value; some “standard” motor lines may also reach high levels for some ratings. Let your specific economic analysis point you toward the best solution for you.
Clean and maintain the HVAC mechanical system regularly for greatest and to maximize efficiency. Check for dirty coils and filters that restrict air flow, loose fan belts, outside air dampers that don’t close correctly and improperly functioning control valves.
Most boilers use more air than necessary for combustion, thereby wasting energy. O2 trimmers adjust the amount of air supplied to the burner, improving efficiency. For example, the installation of an O2 trim system would result in an increase in efficiency of 1 to 2 percent for a 250 hp boiler running 2,000 hours per year. That’s equivalent to an energy cost savings of about $1,700. Initial cost of a unit for a package boiler of this size is approximately $9,000. If the boiler ran for more than 2,000 hours per year, the savings would be correspondingly higher.
Take advantage of peak-use pricing and operate your laundry services during off-peak times. This will also help reduce the load on your facility’s system.
Motor management helps reduce downtime, decreases energy costs and improves productivity. The keys to good motor management:
- Having guidelines for proactive repair/replacing
- Purchasing policies based on lifecycle costing
- Repair policies and best practice repair
- Having a spare motor inventory
- Predictive and preventive maintenance planning
- Implementing a motor survey and tracking program
Following these steps will help you understand your true costs, plan ahead in case of motor failure and ensure you have the right motor on hand when you need it.
Fixtures that have state-of-the-art lamps or ballasts (T8 lamps, electronic ballasts, etc.) often require a higher premium at relamping or re-ballasting time. Much of this cost is offset by their longer life, the reduction of replacement component costs and reduced maintenance costs.
Monitoring a chiller’s kW/ton performance offers additional optimization opportunities and is often achieved for little additional cost. According to Lawrence Berkeley National Laboratory, a true-power kW sensor, which incorporates voltage, amperage and power factor measurements, should be selected to monitor chiller power. For whole plant monitoring, variable frequency drives often offer an economical way to monitor power consumption of smaller, lower-priority loads such as pumps and towers.
Remember that on a life cycle basis, the least expensive part of the system is the fixture and lamp. The most expensive component is the energy that the system uses.
Ozone laundering systems use cold water (vs. hot water), as well as less water, energy and detergent than conventional laundry systems. Ozone laundry systems have a 20-year projected life span and depending on the size and volume of your facility, can reach payback in 1 to 2 years.
Steam traps are automatic valves that release condensed steam from a boiler as they prevent the loss of live steam. They can commonly become stuck in the open position, resulting in significant excess energy use. Ultrasonic leak detectors are designed to detect faulty traps. By isolating sound frequencies, these tools compare the detected frequencies to those of properly functioning traps, and offer users an analysis via digital display.
Even if analysis illustrates that a boiler is operating efficiently, boilers are often oversized and under-utilized during the summer. Your facility may want to consider augmenting its water heating system with a smaller, properly sized boiler for reduced load conditions.
To provide comfort and energy efficiency, be sure to adequately insulate walls, roofs, and floors according to your climate zone. Doing so will provide occupant comfort and increase energy efficiency. Pay special attention to the roof. Roofs are vulnerable to solar heat gain in summer and heat loss in winter.
Uninsulated brick walls are common in buildings constructed before 1960. You can insulate them using one of three common methods: furring, insulating the cavity or insulating the exterior. Furring is the simplest and least expensive, and provides a finished wall surface. It generally involves framing the interior with studs or runners, placing insulation between the runners and finishing the wall surface.
Don’t overwork refrigerators by placing them close to heating vents, kitchen ranges or dishwashers.
By serving meals on a single, larger plate, restaurants and food service operations can save energy costs by reducing the number of plates and dishes that need to be washed.
Inspecting building envelope components should be part of your facility’s overall operations and maintenance plan. Your plan should include a visual survey, repairs of any detected deterioration (such as cracks in roofs and walls insulation) and inspecting windows for leaks.
In order to calculate the power requirements for your data systems, you’ll need data regarding the power required by the cooling system, the uninterruptible power supply (UPS) system, and the IT loads of the center. According to Cisco Systems, Inc., while the power requirements of these elements may vary, they can be estimated accurately once the power requirements of the projected IT load are determined. This calculation can also be used to estimate the power output capacity needed for a standby generator.
Applications for water-loop heat pump systems include schools, medical centers, hotels, offices and even small airports. There are opportunities for energy recovery from core areas and from simultaneous heating/cooling situations. The energy recovered can be redistributed to space conditioning and domestic water heating. Costs are typically low for installing, operating and maintaining these systems, and they are adaptable to future energy sources, such as solar heating.
Pipe insulation will keep cold water pipes from sweating (water vapor condensing on the pipe surface) in warm weather and reduce heat loss from hot water pipes. Moisture is known to contribute to types of corrosion, so preventing condensation from forming on pipework is important. Insulation will also help keep those water pipes located outside from freezing when the ambient temperature drops below freezing. When specifying piping insulation, look at both the maximum and minimum temperatures the pipe will be exposed to and insulate for both.
Well-functioning strip and/or swinging plastic door curtains are a low-cost way to keep cold air from escaping from walk-in coolers. This reduces freezer compressor run times, which saves energy and extends the life of the compressor. Strip curtains also keep warm, moist air from entering the freezer.
Preheating is a common and costly practice. The typical time to preheat most cooking equipment is short–usually 10 to 15 minutes–and some equipment, such as griddles and broilers, require little or no preheating time. Investigate the exact preheating times for all of your equipment, and post the preheat times near the equipment. Train employees to preheat accordingly.
To conserve energy, allow elevators to “time out” and shut down slowly. They should idle long enough for the power consumption to be equal to, or barely less than, the power consumed in starting the motor generator.
If you work with a vending machine company, it should be able to help you evaluate possible upgrades of your current vending machines. ENERGY STAR® qualified vending machines use about 40 percent less energy and keep beverages as standard machines.
Electric, radiant heaters are nearly 100 percent efficient and, unlike gas heaters, do not emit carbon dioxide, nitrous oxide or other toxins. Based on the same principle as the sun, radiant heaters warm the objects in their range—not the air between the heater and the object. By using radiant heat energy, these heaters instantly warm the people and objects within the beam of heat. For this reason, they also work well in the wind.
By decreasing your buildings heating set point to 70 degrees when occupied and to 62 degrees when unoccupied, you could save more than $25,000 per year for a 240,000-square-foot building, according to www.ecova.com.
A thermal storage tank allows you to run chiller equipment off-peak and store cooled water or ice, then draw on this cooling during peak times.
A chiller’s performance is affected by its ability to transfer heat efficiently. If the evaporator and condenser tubes are dirty, it will decrease a chiller’s ability to transfer heat and subsequently increase the compressor’s energy consumption by 30 percent or more.
Clean heat exchangers and perform routine maintenance on refrigerating equipment to ensure efficient operation and to reduce energy costs.
The installation of an economizer, a device that preheats the feedwater (returned condensate), can increase the efficiency of a boiler by 2 to 3 percent. For peak efficiency, repair of replace damage or missing boiler insulation.
According to Alliance for Water Efficiency, depending on the level of treatment necessary, warm-water-recycling equipment can recycle from 10-90 percent of gray or wash water (run off from showers, baths, and laundry) while conserving energy.
Take advantage of Georgia Power’s expert advice and services. We offer technical energy audits, payback calculations, cost comparisons and rate analyses.
To reduce energy costs, turn off ice machines when practical. Additionally, be sure to clean an ice machine’s cooling units regularly. To help reduce maintenance costs, consider models that are self-cleaning.
The further south your facility is located, and the higher the percentage of glass wall space, the more important it becomes to block solar energy and avoid heat gain. In buildings with large areas of south-facing glass, heat gain can cause serious problems in maintaining comfort levels. Window tints or reflective coatings can reflect up to 90 percent of solar heat striking the window. They can provide savings in all but the most northern climates, where heat gain is desirable, helping to reduce winter heat load significantly. Generally, buildings with more than 25 percent glass wall space can benefit from solar control glass.
By utilizing an air-to-air heat exchanger in the dryer, heat recovery systems make use of waste heat by allowing incoming air to be heated by a dryer’s exhaust. They can reduce the amount of energy needed to heat dryers by up to 50 percent.
In summer, ceiling fans help cool a space. In colder months, reverse the direction of the fan and use ceiling fans to circulate the hot air gathered in the ceiling area. Moving air can feel 3 degrees to 5 degrees cooler than non-moving air and can save you 3 percent on cooling costs.
As a group, students are one of the biggest energy users in a school or on a campus. Use outreach, educational and incentive programs to get them involved in energy reduction.
For peak efficiency, repair or replace damaged or missing boiler insulation.
Electronic air cleaners have low, constant air resistance. This low static pressure helps keep energy costs down. A standard filter’s air resistance increases as it gets dirty–increasing fan static pressure, and causing the motor to work harder. Considering installing them in building air handling units instead of standard bad or catridge filters.
Install low-flow faucets and dishwashing equipment in any on-site facilities. Water-saving showerheads create the experience of a 3 to 4 gallon per minute shower, but use significantly less than 2 gallons per minute. You should also repair any water leaks promptly.