Energy FAQs | My Business | Mississippi Power | A Southern Company
  • Katrina 2005-2015
  • Katrina 2005-2015
  • Energy FAQs

    Appliances

    What are some easy ways to save on dishwashing and/or ware washing?

    One of the best ways to reduce dishwashing costs is to purchase insulated models with water saver units and to run the unit with full loads. Some machines have efficiency management features, such as variable cycle controls for smaller loads, but most commercial dishwashing equipment is designed with volume in mind — it operates most efficiently under a full load. Frequent cycling with small wash loads wastes water, energy, and time. While the dishwashing equipment itself is electric, most of the energy used in dish washing is in the form of hot water. Therefore, selecting the method of water heating — be it resistance, heat pump, heat recovery, or gas-fired is an important related decision. Contact your Mississippi Power representative to help you assess your options.

    Cooking

    Do surges (or overvoltages) only go through the electric power system?

    Surges may appear on other systems that enter the building - such as the phone and cable systems, or branch circuits that connect the electrical system to outside lighting and signage. It's recommended that you use secondary surge protection to protect your electrical and data connections at the point of use.

    Does gas cooking equipment cost less than electric?

    Not if you consider the cost an entire cooking line. While there are a few pieces of gas equipment that have a lower first cost than electric — such as ranges and some extremely low efficiency fryers —you need to take the entire cooking line into consideration when calculating your commercial kitchen's equipment costs.

    Does gas cooking equipment recover faster than electric?

    It doesn't. Because electric equipment transfers heat by conduction, which is the most efficient type of heat transfer, recovery is much faster with electric. This also provides electric cooking equipment with a productivity boost.

    Does it cost more to cook with electric or gas?

    Most customers discover that electric cooking is less expensive. The gas bill for cooking goes to $0 when you use electric equipment and the overall energy bill stays the same or goes down because of a reduced load on air-conditioning units.

    How can I be sure I'm getting surge protection for my particular application?

    The correct way to protect electrical devices against surges is by making sure you use a properly designed surge protector that provides protection for the electrical conductors plugged into it. A computer with a network connection must have a surge protector designed to protect the electrical connection as well as the telephone circuit and network cable. Be sure to match the surge protector to the job you're asking it to do.

    How do electric braising pans compare to gas braising pans?

    There are a number of factors to consider when selecting a braising pan: initial cost, food preparation productivity, ease of operation, heat generation in the kitchen, and whether electricity or gas is used as the energy source. But the best choice in cooking equipment is the one that minimizes total operating costs, not just energy costs. Features that reduce labor costs and/or result in higher product yield may outweigh any energy considerations. Be sure to include all these factors in any equipment evaluation.

    How do I know which rate will save my business the most?

    A Mississippi Power expert can run rate analyses that compare your usage against available rates and help you decide the rate that's best for your business. Contact us for more details.

    How do you determine the simple payback of adding energy efficient equipment or processes?

    To determine simple payback, you divide the cost savings from any avoided energy costs by the cost of the new equipment or the cost of installing the new process. Keep in mind there will also be savings associated with any improvement in productivity attributed to the new equipment or process.

    How does using electric cooking equipment cost me less and increase profitability?

    Cooking costs are at the heart of the food service industry, so it's important to select highly productive equipment that cooks the maximum amount of food per hour, at the lowest cost of operation, all while delivering a high quality product. Because productivity is the key to profitability, electric cooking is often the smartest choice. Here are a few advantages that electric has over gas cooking equipment: faster preheat and recovery, superior/even heating, reduced shrinkage, longer service life, lower maintenance cost, reduced ventilation requirements, a cooler working environment, and reduced cleanup time.

    Is gas cooking more efficient than electric cooking?

    No, except when using an open burner range or a woc range. Electric cooking is more efficient than gas cooking, because more heat is absorbed by food cooked on electric equipment than food cooked on gas.

    The equation for measuring efficiency, as established by the University of Minnesota 1984 is: the amount of heat energy (BTUs) consumed by the cooking process divided by the amount of heat absorbed by the food, all times 100.

    Is the purchase price of gas equipment less than electric?

    Not when considering an entire cooking line. There are a few pieces of gas equipment that have a lower first cost than electric, such as ranges and some extremely low efficiency fryers.

    What are some advantages of electric braising pans over braising pans that use gas?

    Although electric and gas braising pans have virtually the same preheating capabilities (both reach a cooking temperature of 300°F in about 10 minutes), electric braising pans have several advantages over gas models: an electric braising pan unit costs an average of 20 to 25 percent less than similar gas models; electric braising pans use less energy than their gas equivalents; the average efficiency of electric models is about 80 percent, while gas model efficiency is just over 50 percent. This higher efficiency translates into less heat into the kitchen, which lowers cooling requirements from the HVAC system. Electric braising pans are also much easier to clean and maintain than gas models.

    What causes oil to break down in a fryer?

    A lot of things: excessive heat or scorching, salts, metal compounds, water soluble fats and trans fatty acids, aeration, oxidation, sunlight, and water.

    Why do chefs prefer cooking with gas?

    Most have been trained on gas equipment, and they are not eager to learn a new method. It is estimated that less than one-tenth of one percent (1/10 of 1%) of all food cooked with gas is sauteed.

    What causes oil to break down in a fryer?

    Excessive heat or scorching
    Salts, metal compounds, or water soluble fats and trans fatty acids
    Aeration, oxidation, and sunlight
    Water

    Which is faster, gas or electric cooking?

    Unless you're using an open burner range or a wok range, electric cooking is faster.

    When cooking, which is fastest to preheat, electric or gas?

    Electric. Conduction is the best form of heat transfer, and electric has quicker heat transfer than gas, so electric is faster to preheat.

    Why is the "cold zone" in an electric fryer better than one in a gas fryer?

    The "cold zone" in an electric fryer is better, because heat travels vertically from the heating elements which are submerged in the cooking oil.

    Will surge protectors prevent my facility from being struck by lightning?

    While surge protectors won't prevent lightning from striking your facility, they will protect your motor driven appliances and other electrical equipment from being damaged by momentary electrical spikes and surges.

    Cooling (HVAC)

    Are economizers best-suited for areas where the weather is colder?

    No, they are useful in warmer climates too. According to Economizer Fundamentals: Smart Approaches to Energy-Efficient Free Cooling for Data Centers, in Atlanta, full economizer operation is possible 11 percent of the year and partial operation 14 percent of the year with a "leaving water" temperature of 45 degrees. When the leaving water temperature is increased to 55 degrees, full economization is available 25 percent of the year and partial economizer operation is available an additional 25 percent of the year. This creates cooling energy savings of up to 43 percent. While economizers may save you more if your business were in Chicago, it still makes sense for facilities in the south to use economizers.

    Can landscaping help to reduce our energy consumption?

    It can. Especially in smaller, low-rise buildings. Deciduous trees (trees that lose their leaves seasonally), provide shade for low, east- or west-facing windows —although these trees should be planted near their mature size in order to achieve significant effect. Trees and shrubs can also control glare emanating from neighboring buildings and surfaces. Landscaping also shades parking lots, helping to reduce pavement temperature and to lower air temperatures around buildings. You can also use plants to control and funnel breezes into ventilated portions of buildings, areas where prevailing wind direction and speed are dependable.

    Due to afternoon sunlight, one side of our building is significantly warmer than the other. What can we do to fix the problem?

    Solar heat gain, particularly in buildings with large areas of glass, can cause serious problems in maintaining comfort levels. In southern climates, west-facing windows have the most solar gain, followed by east. North-facing windows tend to create less of a problem. Window tints or reflective coatings are an inexpensive fix and can reflect up to 90 percent of the solar heat gain striking a window. As a rule of thumb, if the walls of a building are more than 25 percent glass, the building can benefit from solar control glass. The further south and the higher the percentage of glass, the greater the necessity to block unwanted solar energy. That said, it's important to consider how your building behaves in cold weather before taking steps to block heat gain in summer. For instance, south-facing windows can help warm the inside of a building in winter. A Mississippi Power Energy expert can help you factor in all these issues before investing in changes or upgrades. Contac us

    How can window films cut cooling costs?

    Consider a building where many of the offices have large south-facing windows. Even with shades drawn, air conditioning might not keep pace. One option would be to increase chiller capacity. Another option is window films, which can make offices more comfortable without having to add chiller capacity. Window films help reduce electric bills, even if the building occupants continually leave their shades open to enjoy the view. Window films not only reduce air conditioning loads but also help reduce heating energy use. In optimum situations, window films generally pay for themselves in a year or less.

    How can you know if you are simultaneously heating and cooling your space?

    You can conduct an energy audit and/or monitor your electric bills and if you start receiving bills that are unusually high, take notice and figure out why it's so high. When a department store began to receive unusually high electric bills, it investigated and found that half of its 10 rooftop HVAC systems were heating and half were cooling at the same time. By widening the thermostat deadband to prevent simultaneous operation, they were able to fix the problem. And in the office of a manufacturing plant, the refrigerant control valve was stuck open on a large direct expansion (DX) split air conditioning system. As a result, the system was cooling well into the heating season. Because the mixed air controller caused the heating coil to reheat the air, the occupants never knew there was a problem. The faulty valve was discovered during an energy audit. Fixing the valve saved about $1,000 per month.

    How do intelligent cooling controls help optimize energy efficiency in data centers?

    In most data centers, cooling units are sized for peak demand, something that rarely occurs. As a result, many data center cooling systems are over-sized and therefore aren't being utilized efficiently. However, you can use intelligent cooling controls that can make up for this inefficiency. They understand, can adjust —and predict —cooling capacity and airflow based on current conditions in the facility. So rather than cooling being based on return air temperature, it's based on conditions at the servers. A set-up that's much more energy efficient.

    What are some trades offs to consider when evaluating economization options —such as air-side economizers or fluid-side economizers — for cooling systems in highly sensitive environments?

    For spaces that need to monitor humidity carefully — such as data centers, healthcare operations and labs, special considerations need to be made when constructing cooling systems. For instance, the recommended relative humidity for a data center environment is 40 to 55 percent. Utilizing air-side economizers may generate substantial energy savings; the introduction of outside air via an air- side economizer system during the colder months can lower humidity to unacceptable levels. This can cause electrostatic discharge and lead to damaged equipment. You can use a humidifier to maintain appropriate humidity levels, but doing so will offset some of the energy savings the economizer was installed to achieve. Since a fluid-side economizer doesn't introduce outside air into the facility (it uses cooler outside air to cool the fluid loop which cools the cooling systems coils), there's no need to condition that air. These systems are a bit more complex and require more maintenance, but the fact that outside air isn't introduced into the controlled environment by fluid-side economizers makes them preferable to air-side economizers in controlled environments.

    What should be taken into consideration when ventilating a commercial kitchen?

    A properly maintained ventilation system can save energy and create a more comfortable kitchen. Equipment placement, variable speed controls and appropriately balancing makeup air all increase ventilation efficiency. A few simple steps will improve kitchen ventilation, save energy and create a more safe and comfortable environment. First, arrange the cooking appliances based on how much effluent — heat, steam, smoke, grease or carbon monoxide fumes — they produce. Heavy effluent producers, such as char broilers, should be positioned in the center of a hood section rather than at the end. To compensate for air taken out by the ventilation system, make sure the right amount of makeup air is introduced into the kitchen. If your kitchen has a variety of cooking appliances or a variable schedule of appliance use, consider using exhaust fans that accommodate two-speed or variable speed controls. Make sure the access panels are properly installed and sealed, and that all sections of ductwork are accessible for cleaning.

    What's the best way to introduce makeup air into a commercial kitchen ventilation system?

    Ventilation systems work less efficiently with excessive or insufficient amounts of makeup air — the air that's used to replace air that's been exhausted from the space. The best way to introduce makeup air is to integrate your kitchen ventilation system with the building's heating, ventilating, and air-conditioning (HVAC) system so that you're bringing in air from adjacent work or serving areas. You'll want to minimize makeup air velocity near the canopy or hood. It shouldn't exceed 75 feet per minute.

    When purchasing a chiller, what's the best way to size it for optimal efficiency?

    Cooling load conditions can vary wildly, so to choose a chiller based solely on efficiency is probably not the most cost-effective decision. Because chillers rarely operate at full load, the data provided by chiller manufacturers is usually insufficient for making an informed decision. For example, if your facility needs 500 tons at peak load, but only experiences that peak load for 30 days out of the year and the rest of the year needs only 250 tons, the chiller would be operating at a low efficiency almost all the time — with the exception of those 30 days. In a case like this, a good recommendation might be to look at chillers that perform well in the 50 percent range. Mississippi Power Energy Experts can help you explore the advantages of various chiller systems and advise you on how best to maximize your energy dollars.

    Why is low-E glazing on glass important?

    Low-E glazing improves energy efficiency all year. During warm weather, long-wave infrared radiation from outside is blocked from passing through the glass. This reduces the interior cooling load. During cold months, long-wave infrared radiation from inside the building is reflected back into the conditioned space. This lowers heat loss through the glass.

    Heating (HVAC)

    Due to afternoon sunlight, one side of our building is significantly warmer than the other. What can we do to fix the problem?

    Solar heat gain, particularly in buildings with large areas of glass, can cause serious problems in maintaining comfort levels. In southern climates, west-facing windows have the most solar gain, followed by east. North-facing windows tend to create less of a problem. Window tints or reflective coatings are an inexpensive fix and can reflect up to 90 percent of the solar heat gain striking a window. As a rule of thumb, if the walls of a building are more than 25 percent glass, the building can benefit from solar control glass. The further south and the higher the percentage of glass, the greater the necessity to block unwanted solar energy. That said, it's important to consider how your building behaves in cold weather before taking steps to block heat gain in summer. For instance, south-facing windows can help warm the inside of a building in winter. A Mississippi Power Expert, or experienced HVAC, window/door, and other contractors can help you factor in all these issues before investing in changes or upgrades.

    How can you know if you are simultaneously heating and cooling your space?

    You can conduct an energy audit and/or monitor your electric bills and if you start receiving bills that are unusually high, take notice and figure out why it's so high. When a department store began to receive unusually high electric bills, it investigated and found that half of its 10 rooftop HVAC systems were heating and half were cooling at the same time. By widening the thermostat deadband to prevent simultaneous operation, they were able to fix the problem. And in the office of a manufacturing plant, the refrigerant control valve was stuck open on a large direct expansion (DX) split air conditioning system. As a result, the system was cooling well into the heating season. Because the mixed air controller caused the heating coil to reheat the air, the occupants never knew there was a problem. The faulty valve was discovered during an energy audit. Fixing the valve saved about $1,000 per month.

    What are the advantages of using electric radiant heaters to keep customers warm in outdoor areas, such as a patio, during cooler weather?

    If you operate a restaurant with a bustling patio or any outdoor area you'd like to have available in colder weather, there's no need to close it down if the temperature drops. With infrared electric radiant heaters, business patrons stay toasty even on a chilly night. And if you're a restaurant owner or operator, you get to expand the size of your restaurant, serve more customers and increase profits. There are gas heaters available as well, but electric, radiant heaters are nearly 100 percent efficient and, unlike gas heaters, don't emit carbon dioxide, nitrous oxide or other toxic emissions. Electric radiant heaters are based on the same principle as the sun. They warm 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. And, within seconds of being turned on, infrared heaters are at full strength. They're economical, efficient, and effective.

    What are the advantages to using combined heat and power (CHP) systems? Which industries benefit the most from CHPs?

    Also known as cogeneration systems, combined heat and power (CHP) systems use a heat engine or power station to generate electricity and generate heat simultaneously. They do this by converting waste (or exhaust) heat into energy that can be used for heating and cooling. Because such systems use waste heat to produce energy to heat and cool, they're more energy efficient and produce fewer emissions than standard HVAC units. CHP systems are used typically by large energy users and in facilities, such as hospitals, where power interruptions have the potential to be life-threatening. CHP systems can be configured for a "black start," meaning the system can come online without reliance on the electric grid and power critical life-support systems during an emergency.

    What are the benefits of thermal storage for industrial plants and the like?

    A properly designed thermal storage system offers an efficient method of increasing a plant's capacity without having to add chillers. There are several reasons for this, the first is that thermal storage systems can take advantage of off-peak electric rates, which tend to be typically significantly lower. Chilled water systems also operate more efficiently when the outside air temperature is lower. And chilled water storage adds redundancy and can serve as a backup chiller. According to the Lawrence Berkeley National Laboratory, "thermal storage can be linked to free cooling systems, such as water side economizers using cooling towers". By curbing the need to add chillers, thermal storage systems help minimize CO2 emissions as well.

    Why is it important to recover waste heat?

    Waste heat recovery systems — or the process of capturing, converting and reusing "waste" heat — can help you lower your energy costs and reduce greenhouse gas emissions. The captured heat can be used for process or space heating purposes, and when captured from equipment such as absorption chillers or refrigeration equipment, can offset cooling costs. Likewise, waste heat recovered from power generation (such as turbines or engines), can be used to offset heating costs. Be sure that any such heat exhaust is free of contaminants such as corrosive gases or particulates.

    Will upgrading the building envelope help control heat flow and light energy?

    If you're renovating an older building or designing a new one, controlling heat flow and light energy to minimize costs is key. Examine the various strategies for envelope energy conservation and select ones that provide the adequate savings to justify their expense. These strategies include:

    • Incorporating overhangs to shade windows
    • Shading glass surfaces from radiant heat while introducing natural daylight into a building
    • Selecting the appropriate glazing material for exposed window surfaces
    • Selecting the correct materials for opaque surfaces (walls and roof)
    • Using natural ventilation where appropriate

    In smaller, low-rise buildings, landscaping can be used to decrease energy consumption. Planting mature or nearly mature deciduous trees (trees that lose their leaves seasonally) can provide shade for low, east- or west-facing windows. Trees and shrubs can control glare from adjacent surfaces and materials such as neighboring buildings and/or reflective glass surfaces. They can also shade parking lot surfaces, reducing the temperature of paved materials and lowering ambient air temperatures around buildings. Finally, plant materials can be used to control and funnel breezes into ventilated portions of buildings where the direction and speed of the prevailing winds are dependable.

    Lighting/outdoor lighting

    Can you recommend the latest energy-efficiency technologies for retail stores and other, similar commercial facilities?

    There are a number of new technologies, including building automation and energy management systems — systems that provide the optimal amount of energy when the space is in use and limit energy use when the facility is unoccupied. These systems are becoming more affordable, putting them within financial reach of many small businesses and retail operations.

    Lighting products continue to advance as well, with improved fluorescent technology able to meet the higher lighting standards of retail and of commercial spaces with ceiling heights of 20 feet or more. Energy-efficient T5 fixtures initially used for cove lighting have become more popular with retailers because the low profile permits their use in smaller valances and coves. Although the T5/HO (high output) lamp is not more efficient than its cousin, the T8, its higher lumen package helps meet the required vertical illuminance levels for the merchandise, which means less lamps are necessary.

    The use of sensors is increasing as well, including occupancy sensors and carbon dioxide sensors that balance fresh-air intake with energy costs. And retail stores that receive outdoor light can add window films that adjust the amount of outside light — and heat — that can enter a building.

    Please contact us for more details

    Do you have any information on energy savings for automobile dealerships?

    Automobile dealerships are energy-intensive, with facilities consuming about 110 kBTU per square foot (compared to prime office space at 93 kBTU).* While it may not seem like much, over the course of a year, that amount adds up to thousands of dollars in water and energy costs for the typical dealership. Most dealerships have the potential to reduce energy costs by at least 20 percent, while enacting more advanced energy efficiency and energy management approaches will save even more.

    The National Automobile Dealers Association represents approximately 20,000 new car and truck dealers holding nearly 43,000 separate franchises. According to ENERGY STAR, if U.S. dealerships cut their energy use by 10 percent, more than $193 million in utility costs and more than 1 million tons of carbon dioxide could be saved.

    Many dealership showrooms and shop areas contain ceilings 20 feet or higher. The typically installed high-intensity discharge (HID) lighting is inefficient. If you replace these HID fixtures with more efficient metal halide or high-pressure sodium lighting systems, you'll save on energy costs. For even greater efficiency, install T8 or T5 fluorescent lights that are designed specifically for high ceiling applications.

    Pneumatic equipment is important and used often in automobile service areas. It's also incredibly energy intensive and presents an opportunity for energy savings. ENERGY STAR suggests that when choosing compressors or replacing older motors, you select NEMA — National Electrical Manufacturers Association — high-efficiency technology. If your compressors aren't equipped with timers, then install timers on compressors so that they're turned off when your facility is. As with any type of equipment, operate it according to the manufacturer's instructions and keep it well maintained.

    For those facilities that operate paint booths, ENERGY STAR recommends you consider retrofitting them with energy-efficient features like NEMA premium motors and variable speed drives and controls.

    How can I improve my lighting system without spending a lot of money?

    Lighting control is perhaps the most important element of any lighting energy conservation program. Its benefits are concrete, measurable and, in most cases, quickly realized. Many lighting control projects have payback periods of less than one year. On/off controls are most suitable for applications where lighting is not needed for extended periods of time, but where manual switches might be left on. The choice between occupancy sensors and time-based controls should be based on the nature of the operation being performed in the affected space. For example, hallway lighting in office buildings is generally needed only during scheduled hours and therefore well-suited for time-based controls. If lighting is needed on a more random basis, such as private offices, occupancy sensors provide a better level of control and greater energy savings. Daylighting control systems examine the total amount of light available in a given space and switch off one or more banks of lights whenever enough sunlight is available. Daylighting control systems are particularly well suited for use in facilities with large areas of exterior glass.

    How can you reduce lighting costs if you don't have enough capital for a retrofit?

    Lighting is one of the easiest areas to reduce costs without spending a lot of money. One reason is because lighting is one of the largest energy consumers in buildings. According to E Source, lighting consumes nearly 35 percent of the electricity used in commercial buildings in the U.S. And it affects other building systems because lighting produces waste heat and makes your facility's HVAC system work harder. While you may not be able to reap the rewards of a retrofit, there are some quick fixes that produce fast, concrete, measurable benefits. Several lighting control projects have payback periods of less than one year. This is good news for any organization operating on a tight budget.

    Here are a few energy saving options:

    1. Turn off lights when not in use. It's easy to say, but a lot of people don't do it.
    2. Depending on the use of the space and if you have some money in your budget, occupancy sensors and time-based controls could be used.
    3. In facilities with large areas of exterior glass, daylighting control systems work well. But daylighting control systems won't save energy if they're not coordinated with controls that monitor the amount of daylight available in a given space and dim or switch off lights accordingly.
    4. Replace incandescent lamps with compact fluorescent lamps (CFLs) where you can. This might be in light fixtures such as general purpose down lights, in sconces, table lamps, task lights — perhaps decorative lighting like wall washers. CFLs may cost more than incandescent lamps, but CFLs, which last significantly longer than incandescent, quickly pay for themselves through energy — and maintenance — savings. The longer the annual operating hours, the more attractive CFLs become, because you also avoid the cost of incandescent relamping.

    How do I compare outdoor lighting proposals?

    There are several things to consider when you're comparing outdoor lighting options, and each has the ability to increase or decrease your long-term costs. For instance, Lighting Loss Factor (LLF) is specified in a design to create a safety margin for the depreciation of the light output over time. As they're used, lights lose efficacy, and a design that doesn't compensate for LLF won't perform as specified after a few years of exposure and bulb age. A design with a low LLF, usually .8, or a 20 percent margin, will cost more to purchase but less to run, which results in a net savings in the long term. Another thing to consider is average, minimum and maximum foot-candles. Foot-candles are often used as measures of how evenly distributed the light is by a given design. It can be misleading to state an evenness measure in terms of average foot-candles because it is possible to use fewer, higher-power lamps to create a given "average" illumination that is actually quite uneven in areas. While this may result in a lower purchase price, designs translated in average foot-candles could add significantly to your long term operating costs. A good lighting design provides adequate illumination with energy-efficient bulbs by increasing its uniformity. Therefore, a more accurate measure of total cost of ownership is the Uniformity Ratio. This is derived by dividing the average foot-candles by the minimum foot-candles, and a lower ratio is better. A good design typically has a 6-1 ratio. For benchmarking purposes, a 1-1 ratio is only achievable, in practical terms, by the sun.

    How do I judge the uniformity of lighting levels?

    Uniformity is a measure of how evenly or "smoothly" the lighting level is spread out over an area. It is expressed as a uniformity ratio of average foot-candles divided by the minimum allowable foot-candles. The lower this ratio, the better.

    How do you determine if your foot-candle level is adequate?

    Benchmarking. First establish what levels are proven desirable or even required in facilities similar to yours. For example, an office park requires a lower foot-candle rating than a sports stadium.

    How do you determine the simple payback of adding energy efficient equipment or processes?

    To determine simple payback, you divide the cost savings from any avoided energy costs by the cost of the new equipment or the cost of installing the new process. Keep in mind there will also be savings associated with any improvement in productivity attributed to the new equipment or process.

    How does the color of light affect efficiency?

    If it's important to have accurate color under a lighting system, the best choice is Metal Halide lamps. If the color temperature of the light is not important, then High Intensity Discharge (HID) lamps such as high pressure sodium will work. They produce the most light per watt. This lowers costs, especially when lights must be left on all night.

    How high above the ground should foot-candle measurements be taken?

    Given that the light source is located above the ground, it costs more to achieve adequate lighting levels on the ground than it does to achieve them at three feet above street level (and therefore closer to the light source). However, your customers, employees and suppliers all walk and drive closer to the ground than they do to the light source. They also need to be able to see the ground clearly.

    In planning a new build or renovation, what is necessary to consider in terms of heat flow and light energy?

    When designing new facilities or renovations, consider strategies for controlling heat flow and light energy to minimize energy costs. Light energy can be controlled using window overhangs for shade, shading of glass surfaces, and glazing material for exposed window surfaces - along with many other techniques. Methods for controlling heat flow include careful selection of wall and roofing materials, as well as natural ventilation and landscaping. Mississippi Power experts and your other advisors and contractors can help you select strategies which provide a good return on investment (ROI).

    What are some things to consider before retrofitting a warehouse and adding skylighting?

    Cost-effective and energy-efficient, skylights used diffused natural light to illuminates spaces. Using them appropriately can reduce energy costs. They've also been shown to boost productivity and employee morale. According to designlights.org's "Warehousing Skylighting Know How," the optimal spacing of skylights is no more than "1.5 times the ceiling height." It also suggests using a glazing material to diffuse light and reduce glare. Adding a photocontrol system that adjusts electric lights relative to daylighting will further reduce energy costs. To get the most bang for your buck, paint the ceiling and structural elements of the warehouse white.

    What do I need to know about security lighting?

    Security Lighting should provide adequate lighting for safety in these areas:

    • your parking lot
    • along routes to and from your building
    • strategic locations such as rear or hidden entrances

    Brightness should be specified so that it gives enough light for security personnel or police to see suspicious activity but not so much as to create glare in security cameras. It may also be a good idea to install lighting sensors so facade lighting doesn't run during daylight conditions.

    What is solid-state lighting and why is it so revolutionary?

    The Department of Energy (DOE) estimates that by 2030, solid-state lighting (SSL), which is much more energy efficient and longer lasting, could reduce the annual U.S. electricity consumption by about 25 percent (when compared to a scenario with no SSL on the market) — enough energy to illuminate 95 million U.S. homes. An emerging clean energy technology, SSL uses various forms of light-emitting diodes as illumination sources. SSL is expected to make a significant energy and environmental impact over the course of the next decade. By 2025, the DOE's SSL Core Technology Research and Product Development SSL R&D Program hopes to have advanced solid-state lighting technologies that are much "more energy efficient, longer lasting, and cost-competitive" than conventional lighting technologies.

    What is the relationship between artificial lighting and air conditioning?

    Not only are artificial lighting and air conditioning the largest consumers of electricity in a typical commercial building, the two are closely tied. The more artificial light in a building, the greater the heat load imposed on air conditioning systems from lamps and ballasts. By selectively increasing natural light in your space, you can decrease the need for artificial light and reduce the energy required by both lighting and air conditioning systems. Keep in mind that west-facing glass can bring in a significant amount of heat, adding to cooling costs in warmer months. In low-rise to multi-story consider planting trees that lose their leaves (deciduous) to help shade the glass. In summer, when you don't want the heat from the outdoor light, the leaves will block it. In winter, when you want the added warmth, the trees will have shed their leaves and will let the sun — and its warmth — filter through.

    Why should I invest in facade and landscape lighting and, if I do, any rules of thumb?

    Lighting facades and landscapes adds beauty, attracts attention and can advertise your facility to potential customers. Since these types of lighting fixtures are typically hidden from view, it makes sense to choose less expensive — yet sturdy — fixtures. For maintenance purposes, mount the fixtures so they can be accessed easily. And angling the light upward will reduce glare and bring out the textures of the building and landscape elements. It may also be a good idea to install lighting sensors so facade lighting doesn't run during daylight conditions.

    Will upgrading the building envelope help control heat flow and light energy?

    If you're renovating an older building or designing a new one, controlling heat flow and light energy to minimize costs is key. Examine the various strategies for envelope energy conservation and select ones that provide the adequate savings to justify their expense.

    These strategies include:

    • Incorporating overhangs to shade windows
    • Shading glass surfaces from radiant heat while introducing natural daylight into a building
    • Selecting the appropriate glazing material for exposed window surfaces
    • Selecting the correct materials for opaque surfaces (walls and roof)
    • Using natural ventilation where appropriate

    In smaller, low-rise buildings, landscaping can be used to decrease energy consumption. Planting mature or nearly mature deciduous trees (trees that lose their leaves seasonally) can provide shade for low, east- or west-facing windows. Trees and shrubs can control glare from adjacent surfaces and materials such as neighboring buildings and/or reflective glass surfaces. They can also shade parking lot surfaces, reducing the temperature of paved materials and lowering ambient air temperatures around buildings. Finally, plant materials can be used to control and funnel breezes into ventilated portions of buildings where the direction and speed of the prevailing winds are dependable.

    Medical waste technologies

    What are the major factors affecting medical waste management today?

    Increasing waste volume, limited landfill capacity, increasing landfill cost and regulatory change are placing negative pressure on current status quo options.

    How fast are medical and infectious wastes growing?

    The American Hospital Association's Guide to the Health Care Field, 1992 Guide, indicates medical waste is growing more than 5% annually, while infectious waste is growing even more rapidly.

    What federal agencies are involved in regulating medical waste management?

    Five federal agencies administer regulations affecting medical waste management: the Environmental Protection Agency (EPA), the Centers for Disease Control, the Occupational Safety and Health Administration (OSHA), the Department of Transportation, and the Nuclear Regulatory Commission. Each agency utilizes slightly different definitions and handling of medical waste.

    Why not continue using landfills for medical waste disposal?

    Traditionally, medical waste has been hauled to landfills or other disposal facilities in essentially unmodified form. However, landfill space is dwindling and dumping and transportation costs and regulations are rising, so this approach is rapidly becoming obsolete. In addition, untreated or even treated medical waste dumped in landfills carries enormous "cradle to grave" liability risks for the facility that generated the waste. New regulations enforcing the use of line landfills with leachate collection systems have forced the closing of many older landfills.

    Why not continue using on-site incinerators for medical waste disposal?

    Incinerators can be used to burn medical wastes, and have, in fact, historically been the on-site treatment choice for most health care facilities. However, rising environmental concerns and corresponding increases in regulations are making incineration of medical waste an unattractive option. The EPA's proposed rules for medical waste combustors are targeted to control the emission from both existing and new sources. The pollutants affected are particulate, SO2 NOx, carbon monoxide (CO), hydrogen chloride (HCl), dioxins, furans, lead, cadmium, and mercury. If combustion is used, you can expect dry sorbant injection, fabric filter, carbon injection, or tighter combustion controls for temperature and retention time. In addition to the Clean Air Act's profound effect on the operation of incinerators, the telltale smokestack, plume, and odor identify the incenerator's location, and also create a negative image that may raise public reaction.

    In general, what are the best options for managing medical waste?

    There are options available that provide a highly positive impact on employee safety, patient safety, the environment, cost management, and control of your health care facility's destiny. These options utilize on-site treatment of medical waste using any of several non-polluting, cost effective, electric technologies.

    What is the best way for a facility to reduce the liability associated with the medical waste that the facility produces?

    "Cradle to grave" liability is substantially reduced via on-site disposal, which eliminates transportation of untreated waste. It is further reduced by disposal processes that sterilize the medical waste and convert it into a non-recognizable residue.

    Motor driven equipment

    Can you offer some basic troubleshooting tips for motors?

    You can arrive at some basic troubleshooting tips for motors by asking and answering a series of questions, such as, what exactly are the symptoms? In terms of measured conditions - how much (or little), how often, what, when, where — are needed details when addressing motor operational issues. Other questions to ask:

    How long has this particular trouble been occurring? Did it start recently, or has it been ongoing?

    No matter how seemingly insignificant, were there any changes in equipment, operations or maintenance practices that took place about the same time the troubles began?

    How accurate is the evidence of trouble? If meters were used, what kind were they, and how were they connected?

    What are the ratings — nameplate voltage, current, etc. — of all components involved in the problem (e.g., motors, contactors, fuses, circuit breakers)? You can't assume the equipment voltage rating matches the circuit, so check it.

    What's the circuitry involved? Is a three-phase transformation open delta or open wye rather than a full set of three transformers? If a motor trips off unexpectedly, or won't start, just how is it controlled? You should have on hand some basic one-line and schematic diagrams should be available showing how things are presently, rather than how they were configured months or years ago.

    What specific actions have been taken to correct the trouble? What were the results? Asking these questions should help you uncover the source of the problem.

    How can I be sure I'm getting surge protection for my particular application?

    The correct way to protect electrical devices against surges is by making sure you use a properly designed surge protector that provides protection for the electrical conductors plugged into it. A computer with a network connection must have a surge protector designed to protect the electrical connection as well as the telephone circuit and network cable. Be sure to match the surge protector to the job you're asking it to do.

    Should I rewind a failed motor?

    While failed motors are usually able to be rewound, it's often worthwhile to replace a damaged motor with a new energy-efficient model. Doing so will save energy and improve reliability. According to www.motors.doe.gov, when calculating operating costs for rewound motors, you deduct one efficiency point for motors exceeding 40 hp and two points for smaller motors. It suggests having motors rewound at reliable repair shops "that use low temperature (under 700°F) bakeout ovens, high quality materials, and a quality assurance program based on EASA-Q or ISO-9000." It also suggests asking the repair shop to conduct a "core loss or loop test" as part of the rewind procedure.

    Should larger or smaller companies consider having a motor management plan?

    Any company, large or small, that utilizes electric motors should have a motor management plan. With a proactive motor plan in place, you'll be able to make efficiency improvements to equipment that operates for thousands of hours per year. Even small reductions in energy use can result in substantial cost savings and an increase in profitability. According to a study by Motorsmatter.org, a 1 percent increase in motor efficiency over the 10-year life of a motor almost recoups the initial price of the motor. There are also non-energy benefits to consider — such as less noise, reduced equipment downtime, and longer motor life. Various software and third party tools can help you estimate your annual motor operating costs.

    What does it mean if a motor is designated as being "premium?"

    A premium motor is one that's been designated such by NEMA, the National Electrical Manufactures Association. NEMA created the "premium" standard beacause it believes that standards play, according to www.nema.org, "A vital part in the design, production, and distribution of products destined for both national and international commerce. Sound technical standards benefit the user, as well as the manufacturer, by improving safety, bringing about economies in product, eliminating misunderstandings between manufacturer and purchaser, and assisting the purchaser in selecting and obtaining the proper product for his particular need." Motors are only one of the products or pieces of equipment that NEMA classifies.

    What does the Suppression Voltage rating mean?

    A surge protection device listed under UL 1449 is given a voltage "let-through" rating by the independent testing company, UL. This rating represents the highest transient voltage the suppressor allowed to pass into the protected load (whatever is plugged into the surge protector) under test conditions. You can use let-through ratings as a way to compare one suppressor to another. We suggest a maximum let-through voltage of 500 volts.

    What is the average cost difference between a standard efficiency motor and one classified as premium efficient?

    The costs differences vary by motor size, type and availability. Premium efficiency motors can cost 20 to 30 percent more than non-premium motors, but some cost less or are competitively priced. Even in cases where the premium motor is more expensive, the cost difference is insignificant when compared to the amount of energy the motor will save long term.

    Why are motor nameplates so important?

    A metal plate located on the side of a motor, the nameplate is a motor's single most important component. The reason is because NEMA (National Electrical Manufacturers Association) standards require that certain information be listed on all AC motor nameplates. Without the serial number, for example, the manufacturer probably can't identify the specific design and answer questions about it. Without the frame size designation, no dimensional questions can be answered. The RPM is a must when comparing two motors to drive the same load. Temperature rating defines suitability to different surroundings. And the code letter permits prediction of motor starting capability. The major items any nameplate must display are:

    1. Manufacturer type and frame designation.
    2. Horsepower output and time rating (e.g., "continuous").
    3. Phase, frequency, and full-load rpm.
    4. Voltage and full-load amperes.
    5. Code letter indicating locked-rotor kVA (usually a letter from D through K).
    6. Design letter (usually B, C or D; unrelated to the code letter).
    7. Service factor, if other than 1.0.
    8. Maximum ambient temperature and insulation system designation.
    9. Nominal full-load efficiency when applicable (required for 1-125 hp, singlespeed, low-voltage, etc.).

    Office equipment

    Do surges (or overvoltages) only go through the electric power system?

    Surges may appear on other systems that enter the building - such as the phone and cable systems, or branch circuits that connect the electrical system to outside lighting and signage. It's recommended that you use secondary surge protection to protect your electrical and data connections at the point of use.

    How can I be sure I'm getting surge protection for my particular application?

    The correct way to protect electrical devices against surges is by making sure you use a properly designed surge protector that provides protection for the electrical conductors plugged into it. A computer with a network connection must have a surge protector designed to protect the electrical connection as well as the telephone circuit and network cable. Be sure to match the surge protector to the job you're asking it to do.

    How do you determine the simple payback of adding energy efficient equipment or processes?

    To determine simple payback, you divide the cost savings from any avoided energy costs by the cost of the new equipment or the cost of installing the new process. Keep in mind there will also be savings associated with any improvement in productivity attributed to the new equipment or process.

    Is it important for the surge protector to have a UL label?

    The UL Mark on a product means that UL, an independent safety science company, has tested and evaluated the product and determined that it meets UL requirements. At Mississippi Power, we recommend that the surge protection chosen for an electrical supply be listed by UL under the UL 1449 listing. UL provides the voltage that the surge protection device lets pass through under the UL test. For a 120 volt application, we suggest you choose a surge protector with a UL listing less than 500 volts.

    Most businesses lease space. What's the best way to affect energy initiatives if we don't own the space?

    Figuring out how your lease is structured and what that means in terms of energy costs can be complex. Is your lease fixed-base, net, plus lights & plugs, tenant electric, none of the above? Clarifying such energy questions as how usage is measured as well as who benefits from increased efficiencies is worthwhile. And it's best to do this before you sign the lease. Leases that incent tenants to limit energy use create a win-win for tenants and owners alike.

    What are some important features of a surge protector?

    We recommend four features: one, indicators that the device is working and not damaged; two, thermal fusing to reduce the possibility of fire should the surge suppressor fail; three, protection against short circuits by either fuses or circuit breakers; and four, that it's constructed of quality materials.

    What is an "automatic cutoff" feature in a surge protector?

    Surge protectors degrade over time. This is because the majority of surge protectors rely on a metal oxide varistor, or MOV, to work. MOVs only conduct electricity if and when the power level reaches an excessive level. That excess power is rerouted automatically to the ground wire, which safely dissipates the excess electricity into the ground. But over time, MOVs degrade. That's why it's good to buy a model with a failure indicator. And some models come with an automatic cutoff or auto shut-off safeguard. These models cut off power to the surge protector if and when the MOV has degraded to the point where it can no longer adequately protect any connected equipment.

    What's the best way to keep equipment from failing following a power outage?

    Equipment failure during or after a power outage is usually caused by a surge. When heavy electrical loads are started — or restarted, as is the case after an outage — the initial current is often much higher than normal running current. Because supply and cabling are usually dimensioned for normal current levels, the high level of initial current following an outage can cause a voltage drop that leads to equipment failure. To minimize surges, turn off all equipment after each outage and restart each piece of equipment one at a time. To protect your equipment, you may want to consider investing in a whole-building suppression system or an uninterruptible power supply (UPS).

    Will surge protectors prevent my facility from being struck by lightning?

    While surge protectors won't prevent lightning from striking your facility, they will protect your motor driven appliances and other electrical equipment from being damaged by momentary electrical spikes and surges.

    Rates

    How do I know which rate will save my company the most?

    We can run rate analyses to compare your usage against the rates available and help you decide which rate is best for your business. Contact us for more details.

    Refrigeration

    Do surge protectors make sense for refrigerator equipment?

    Yes, they do. Just as electronic equipment can be damaged by large voltage surges, so can refrigerators.

    How can I be sure I'm getting surge protection for my particular application?

    The correct way to protect electrical devices against surges is by making sure you use a properly designed surge protector that provides protection for the electrical conductors plugged into it. A computer with a network connection must have a surge protector designed to protect the electrical connection as well as the telephone circuit and network cable. Be sure to match the surge protector to the job you're asking it to do.

    How can surge protectors help me?

    Properly installed surge protectors help prevent damage to electronic equipment caused by large, momentary voltage surges. These surges are associated with events such as lightning strikes, short circuits, load switching, equipment failure, and similar unusual events.

    What are some important features of a surge protector?

    We recommend four features: one, indicators that the device is working and not damaged; two, thermal fusing to reduce the possibility of fire should the surge suppressor fail; three, protection against short circuits by either fuses or circuit breakers; and four, that it's constructed of quality materials.

    What's the best way to keep equipment from failing following a power outage?

    Equipment failure during or after a power outage is usually caused by a surge. When heavy electrical loads are started — or restarted, as is the case after an outage — the initial current is often much higher than normal running current. Because supply and cabling are usually dimensioned for normal current levels, the high level of initial current following an outage can cause a voltage drop that leads to equipment failure. To minimize surges, turn off all equipment after each outage and restart each piece of equipment one at a time. To protect your equipment, you may want to consider investing in a whole-building suppression system or an uninterruptible power supply (UPS).

    With commercial refrigeration equipment, how long should a defrost cycle last?

    Try to keep the length of the defrost cycle to a minimum — long enough to clear the coil of frost (with minimal heat gain into the space), yet short enough to prevent the evaporator coil from getting too hot and "steaming." Normally, defrost cycles are time initiated with a temperature termination set point controlling the length of the cycle. Temperature set point controls can be adjusted, and while they offer more flexibility than fixed controls, they're not as economical.

    Ventilation (HVAC)

    How much energy does a typical fume hood consume? Why is it so much?

    Although barely a few feet tall, a typical laboratory fume hood consumes an average of $5,000/year (and as much as twice as much in hot climates). In response, the Lawrence Berkeley National Laboratory is developing a high-performance fume hood that it claims could save more than half of the $3.2 billion spent in the U.S. each year on energy associated with fume hoods — and enhances worker safety. By improving a fume hood's containment performance and lowering the necessary amount of airflow, efficient hoods could allow for more work stations and, as a result, more research productivity. For a link to info about the project or to measure your current fume hood efficiency: http://fumehoodcalculator.lbl.gov/

    In planning a new build or renovation, what is necessary to consider in terms of heat flow and light energy?

    When designing new facilities or renovations, consider strategies for controlling heat flow and light energy to minimize energy costs. Light energy can be controlled using window overhangs for shade, shading of glass surfaces, and glazing material for exposed window surfaces — along with many other techniques. Methods for controlling heat flow include careful selection of wall and roofing materials, as well as natural ventilation and landscaping. Mississippi Power experts and your other advisors and contractors can help you select strategies which provide a good return on investment (ROI).

    What are some tradeoffs to consider when evaluating economization options — such as air-side economizers or fluid-side economizers — for cooling systems in highly sensitive environments?

    For spaces that need to monitor humidity carefully — such as data centers, healthcare operations, or labs, special consideration needs to be made in the design of the cooling system. For instance, the recommended relative humidity for a data center environment is 40 to 55 percent. While utilizing air-side economizers may generate substantial energy savings, the introduction of outside air via an air- side economizer system during the colder months could lower humidity to unacceptable levels and result in damaged equipment. You could use a humidifier to maintain appropriate humidity levels, but doing so offsets some of the energy savings the economizer was installed to achieve. A fluid-side economizer doesn't introduce outside air into the facility because it uses cooler outside air to cool a fluid loop which cools the cooling systems coils. As a result, there's no need to condition that air. Fluid-side systems are a bit more complex and require more maintenance than air-side economizers, but the fact that outside air isn't introduced into the controlled environment can make them preferable to air-side economizers in controlled environments.

    What is Demand-Controlled Ventilation and how does it reduce energy costs?

    A demand-controlled ventilation (DVC) system is able to sense the C02 levels in the air to determine if the space is occupied. If the space is unoccupied, the DVC system adjusts your facility's HVAC system so it won't work so hard. The less people in the space, the less work your HVAC system is asked to do, the more you save on energy costs.

    What should be taken into consideration when ventilating a commercial kitchen?

    A properly maintained ventilation system can save energy and create a more comfortable kitchen. Equipment placement, variable speed controls and appropriately balancing makeup air all increase ventilation efficiency. A few simple steps will improve kitchen ventilation, save energy and create a more safe and comfortable environment. First, arrange the cooking appliances based on how much effluent — heat, steam, smoke, grease or carbon monoxide fumes — they produce. Heavy effluent producers, such as charbroilers, should be positioned in the center of a hood section rather than at the end. To compensate for air taken out by the ventilation system, make sure the right amount of makeup air is introduced into the kitchen. If your kitchen has a variety of cooking appliances or a variable schedule of appliance use, consider using exhaust fans that accommodate two-speed or variable speed controls. Make sure the access panels are properly installed and sealed, and that all sections of ductwork are accessible for cleaning.

    What's the best way to introduce makeup air into a commercial kitchen ventilation system?

    Ventilation systems work less efficiently with excessive or insufficient amounts of makeup air — the air that's used to replace air that's been exhausted from the space. The best way to introduce makeup air is to integrate your kitchen ventilation system with the building's heating, ventilating, and air-conditioning (HVAC) system so that you're bringing in air from adjacent work or serving areas. You'll want to minimize makeup air velocity near the canopy or hood. It shouldn't exceed 75 feet per minute.

    Will upgrading the building envelope help control heat flow and light energy?

    If you're renovating an older building or designing a new one, controlling heat flow and light energy to minimize costs is key. Examine the various strategies for envelope energy conservation and select ones that provide the adequate savings to justify their expense.

    These strategies include:

    • Incorporating overhangs to shade windows
    • Shading glass surfaces from radiant heat while introducing natural daylight into a building
    • Selecting the appropriate glazing material for exposed window surfaces
    • Selecting the correct materials for opaque surfaces (walls and roof)
    • Using natural ventilation where appropriate

    In smaller, low-rise buildings, landscaping can be used to decrease energy consumption.

    Planting mature or nearly mature deciduous trees (trees that lose their leaves seasonally) can provide shade for low, east- or west-facing windows. Trees and shrubs can control glare from adjacent surfaces and materials such as neighboring buildings and/or reflective glass surfaces. They can also shade parking lot surfaces, reducing the temperature of paved materials and lowering ambient air temperatures around buildings. Finally, plant materials can be used to control and funnel breezes into ventilated portions of buildings where the direction and speed of the prevailing winds are dependable.

    Water heating

    How can I increase boiler efficiency?

    Install an economizer. It can improve a boiler's effciency by 2-3 percent by preheating the boiler's feedwater (returned condensate). In the case of a 250-horsepower boiler, an initial investment of $6,000 provides an annual savings of more than $3,000. Economizers generally pay for themselves within two years and can save thousands of dollars in annual energy costs.

    How can we get control of excess water usage in our kitchen and restrooms?

    In addition to electricity usage, sit-down restaurants also spend significant amounts of money on water to operate their kitchens and bathrooms. Small changes can add up to big savings. Here are a few cost-cutting steps: Turn off dishwashers when not in use and wash only full loads; scrape dishes rather than rinsing before washing, presoak utensils and dishes in basins; use connectionless steamers in lieu of boilered units. These efficient units can save more than $1,200 per year in water alone; install flow regulators on dishwashers or install high-efficiency spray heads; Set dishwasher rinse pressure to 15-25 pounds per square inch (100-172 kilopascals) to avoid excess water use; use water from steam tables to wash down cooking areas; turn off faucets and continuous flows in areas such as food prep and wash-down when not in use; consider installing foot triggers in bar sinks or other heavy-use areas; adjust ice machines to reduce waste and/or install high-efficiency ice machines; minimize flow of water to garbage disposal, troughs, dipper wells and other equipment or utensils. In restrooms, replace standard faucets with water-saving models. and install low-volume aerators on your faucets.

    How do you determine the simple payback of adding energy efficient equipment or processes?

    To determine simple payback, you divide the cost savings from any avoided energy costs by the cost of the new equipment or the cost of installing the new process. Keep in mind there will also be savings associated with any improvement in productivity attributed to the new equipment or process.

    Is one, centralized water heater enough for my facility?

    Although a hot-water system accounts for only about 4 percent of a building's total energy consumption (that figure is higher in buildings that have a laundry or restaurant), increasing the system's energy efficiency is still worthwhile.

    Energy savings can be achieved by placing water heaters close to usage points rather than installing a single central generation tank and long runs of hot-water piping. To determine whether the installation of local units would be advantageous in your situation:

    • Analyze the building's hot water demand patterns
    • Estimate the existing system's total energy losses
    • Calculate the local water heating units' potential savings

    The energy saved is the sum of the reduced distribution losses and the increase in the average generation efficiency of local units, as compared to a central system.

    A water heater's energy efficiency can be increased in other ways as well. The storage tank, supply piping and recirculating piping can be insulated to reduce energy losses due to radiation, convection and conduction. Strictly observing water temperature guidelines and informing tenants of efficiency measures can also help conserve energy. Operating a water heater at the lowest practical temperatures can also help minimize wear and tear on tanks and pipes. For instance, if guidelines suggest keeping the water heater set between 120-140°, you can use a local booster heater to supply any equipment (such as a dishwasher) that requires higher water temperatures.

    Our engineer is suggesting a heat-pump water heater for our new building because we'll have an indoor pool. What's the rationale behind that? Could we use traditional equipment?

    While you could use traditional equipment — a highly efficient condensing boiler with variable speed drives on the pump motors would be energy efficient — indoor swimming pools pose a challenge as they require simultaneous heating and dehumidification. Heat-pump water heaters efficiently tackle both those needs by heating water and producing cool air — air that lowers the temperature of the room where the pool is located and lowers the humidity in the room. If you have a lot of available sunlight, you may want to research low-temperature unglazed solar water heaters. They tend to be inexpensive and well suited for some climates.

    Should we replace our boiler?

    To determine whether to replace your boiler system, you'll need to calculate the expected energy savings. You do this by comparing rated energy consumption at various loads for both the old and the new boiler systems. As these calculations can get complicated, you may want to contact your Mississippi Power team for assistance.

    What are some easy ways to save on dishwashing and/or ware washing?

    One of the best ways to reduce dishwashing costs is to purchase insulated models with water saver units and to run the unit with full loads. Some machines have efficiency management features, such as variable cycle controls for smaller loads, but most commercial dishwashing equipment is designed with volume in mind — it operates most efficiently under a full load. Frequent cycling with small wash loads wastes water, energy, and time. While the dishwashing equipment itself is electric, most of the energy used in dish washing is in the form of hot water. Therefore, selecting the method of water heating — be it resistance, heat pump, heat recovery, or gas-fired — is an important related decision. Contact your Mississippi Power representative to help you assess your options.