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4 Ways To Reduce Your School's Electric Bill Without Breaking The Bank

Think back to Super Bowl XLVII, February 3rd, 2013. For the first time, the Super Bowl featured two brothers coaching against one another—Jim and John Harbaugh, the head coaches of the San Francisco 49ers and Baltimore Ravens, respectively—earning it the nickname “The Harbaugh Bowl.”

You may not remember every detail of the game (unless you’re a football junkie), but there’s probably one specific moment you can recall: the moment the lights went out.

Minutes into the third quarter, a piece of equipment monitoring the electrical load of the facility detected an abnormality in the system, partially cutting power, plunging both teams and the 71,000 fans in attendance into near-darkness for over 30 minutes. Suddenly, lighting was on the minds of millions of people across America.

Although schools don’t have to worry about a power outage affecting millions of people across the country, lighting remains significant in the classroom—and on the budget sheet. According to the Department of Energy, about 30 percent of electricity consumed by a typical school is for lighting alone. In some cases, additional electricity is required to run air conditioning units due to the coincidental heat generated by outdated light fixtures. (Jim Messner, 2017)

Whether you’re remodeling your school, looking to reduce energy and maintenance costs, or simply want to improve light quality, a lighting upgrade doesn’t have to break the bank. Here are a few ways to reduce your school’s energy bill through lighting:

Occupancy Sensors

Schools and universities are a niche where occupancy-based lighting controls can drastically cut down on the energy costs of a lighting system.

Occupancy Sensor

Most building codes now mandate occupancy sensors that turn off all non-emergency lighting when a room is empty. Occupancy sensors can be programmed to turn off the lights after a time delay of 15 or 30 minutes of non-use (the delay period can also be adjusted to maximize energy savings). (Jim Messner, 2017)

In fact, occupancy sensors are the single most-effective energy-saving upgrade for restrooms. Since restrooms are typically vacant more than they are in use, using an occupancy sensor to shut off the lights during vacant hours can yield an outstanding payback. Similarly, occupancy-based lighting controls can be installed in hallways and stairwells, which see highly-intermittent traffic throughout the day, and where constant lighting is unnecessary and wasteful.

A key study, developed for the Illuminating Engineering Society (IES), found that installing occupancy sensors in public restrooms yielded energy savings of 73-86%; additionally, the Department of Interior states that occupancy sensors reduce energy usage up to 46% in classrooms, and according to a UC Davis study, occupancy-based lighting controls in corridors can reduce lighting power during unoccupied periods by 46-65% while automatically restoring full light output when occupants enter the space.

Blending Natural Light with Artificial Light

Taking advantage of the natural light produced by the sun is the next step to improving lighting and reducing energy costs in your school. Studies have shown that natural light provides a wide variety of benefits in an educational environment, including improved focus, boosted productivity, and better student health.

A study carried out by the Heschong Mahone Group—a consultancy firm in the energy efficiency industry—found that students scored a staggering 25 percent better on standardized tests in a naturally-lit environment than they did under artificial light.

Students at Hood River Middle School enjoy passively daylit classrooms

On top of improving educational achievement and learning skills, being exposed to natural light improves overall health. A study found that students who studied under in naturally-lit classrooms were happier, healthier, and less likely to be absent due to illness. Surprisingly, the same study revealed that students who studied in artificially-lit environments had lower rates of educational achievement, increased fatigue, higher rates of absenteeism, and higher levels of stress.

Of course, natural light isn’t always available. At night, on cloudy days, or short winter afternoons, schools need to be able to augment and increase light through artificial sources. Luckily, advances in lighting control systems and lighting fixtures have made artificial lighting more affordable and efficient. A common practice that has begun finding its way into more schools is daylight harvesting—or varying the amount of artificial light produced based on the amount of natural light that is available.

Daylight harvesting works by placing sensors in around a classroom that measure the amount of natural light and automatically adjust the lights to meet the desired light levels. As more natural light floods the classroom, the artificial lights get dimmer to maintain a consistent light level. If a cloud passes overhead, the lights in the room automatically increase their output to again maintain consistent light levels.

Often times, the brightening or dimming of the lights is so subtle that teachers and students rarely notice. School administrators will notice, however, when they see the savings on their electric bill.

Brief History of Natural Light in Schools

Back in the 1970s, it was believed windows were an opportunity for distraction among students. Architects would scale down school windows in an effort to curb these distractions off the simple—and completely incorrect—idea that big windows would cause students to look out into the environment instead of focusing on schoolwork.

Jumping ahead to present day, many of those architects have adopted the opposite approach—with a far better result. Rather than distracting students, natural lighting can actually help students focus and become far less distracted. (Jim Messner, 2017)

LED vs Fluorescent

Switching from fluorescent light fixtures to LED light fixtures is another way for schools to save money on their electric bill. On average, the operational lifespan of new LEDs is 50,000-100,000 hours or more. By comparison, the lifespan of a typical fluorescent bulb is 10 to 25 percent as long, at best (roughly 10,000-25,000 hours). In addition to longer lifespans, LED light fixtures are up to 15 percent more efficient than their fluorescent counterparts.

Although LEDs have a higher cost than fluorescent lights, the price of LEDs has dropped more than 85% in recent years. To further offset the cost, most utility companies offer rebates that cover nearly 50 percent of the fixture cost to help incentivize the use of LEDs. Between the rebates offered by utility companies and the decreased operational and maintenance costs, an LED lighting system in your school can have a payback in as little as three years.

LED fixtures also have the benefit of being dimmable right out of the box. This is an improvement of fluorescent fixtures which require expensive dimming ballasts. Dimming is another energy saver for schools, in terms of daylight harvesting as previously described and manually dimming when teachers need to dim the lights to use a whiteboard, projector, or other AV device. Providing a manual dimming system allows teachers to tune the lighting to meet the needs of a specific activity or to create a mood within the classroom. (Jim Messner, 2017)

Lighting Control Systems

Lighting control enhancements were hard to justify in the past. Contractors or building owners would need to visit each room and make adjustments at each sensor to adjust the time delay for an occupancy or daylight sensor. This process made it difficult to verify that each sensor had the correct adjustment.

Lighting ControlsSince then, lighting control systems have improved by integrating them into a networked lighting control system which feeds data to a central processor regarding the electrical usage of light fixtures for the entire school. Facility managers can receive real-time updates on energy savings and electricity usage instead of having to wait for a monthly electric bill or having to wait a full calendar year to benchmark results.

System-wide changes become easier, as well; instead of a technician manually resetting every single switch in the entire school, the settings for occupancy and daylight sensors can be adjusted from the central processor, saving time and money.

How Can I Get Started?

If your school is interested in installing a new lighting system, lighting controls, and/or lighting sensors, the first step in the process is to conduct an audit of your facilities. An audit should be carried out by a lighting professional; the lighting company will gather your district's energy consumption data, evaluate which solutions are the best fit for your school(s), and then present the findings to your administration's decision-makers to obtain their support.

Energy Performance Lighting provides investment-grade audits using a comprehensive assessment with room-by-room exact pricing of exterior and interior lighting. Once the assessment is complete, EPL develops lighting upgrade options in a “Good, Better, Best" format with varying savings, price points, and payback windows. In addition, EPL offers budget development at no cost to school districts. We calculate within 10% of the project’s total cost and payments can be broken up into annual plans.

In Conclusion

If you’re looking for a way to improve the environment for your students and teachers, a lighting upgrade may be the solution. For more information, or to schedule on audit, contact the Lighting Certified specialists at Energy Performance Lighting by email or phone at (608) 661-5555, or you can click here to schedule a lighting service. Complete our simple assessment form and an EPL team member will contact you within 24 hours to discuss solutions for your building(s).

 

 


(This blog was adapted from School Lighting Design: Systems, Sensors, and Controls, 2017)

What's CRI?

Have you ever noticed that objects look different under artificial lighting than they do under natural lighting? This effect on our perception can cause us to make hasty judgements, like "eating with our eyes," or cause us to make mistakes, like matching black socks with navy ones. Whether we appreciate it or not, the traits of a light source can have a significant effect on our daily lives.

Consider when you go shopping for light bulbs; what are some products facts you typically look for on the lighting label? The brightness and lumens output, the estimated annual energy cost, the light’s color temperature (either warm or cool), and of course the bulb’s life expectancy. Now it’s time to add another trait to the list: the bulb’s CRI.

What is CRI?

CRI stands for color rending index measures and compares (on a scale of 0 to 100) the ability of a light source to accurately reproduce the color of an object under artificial light. An LED bulb that perfectly replicates the sun has a CRI of 100, allowing objects to appear clearly, and naturally, and colors to appear truer across a wide spectrum. Surprisingly, halogen and incandescent bulbs, despite their awful energy efficiency, produce a full, natural and excellent light spectrum with a CRI of 100.

Understanding the CRI value of a light bulb is easy: the higher the bulb’s CRI, the more vibrant the colors will appear. The lower the CRI, the duller the colors will appear. A light bulb with a CRI rating of 80 or more is good for most applications, and a bulb with a CRI of 90 or more is considered excellent. Bulbs with a CRI of 80 and below are generally considered poor and cause colors to appear washed out and harder to differentiate.

Be aware that a light’s color rending index is a separate measurement from its color temperature (or “CCT”—correlated color temperature—in fluorescent lights and LEDs). Color temperature is measured in degrees of Kelvin (K) on a scale from 1,000 to 10,000.

How Color Works

Natural daylight is the combination of all the colors in the visible light spectrum. The color of sunlight itself is white, but the color of an object under the sun is determined by the color reflected by the object.

For example, an apple appears red because it absorbs all the colors of the visible spectrum except for red, which it reflects. When using an artificial light source, such as an LED lamp, we’re attempting to reproduce the colors of natural daylight in such a way that objects appear the same as they would under natural light. In some cases, the reproduced color will appear similar, and other times it appears quite different. The similarity of the color reproduced compared to the color under natural light is what CRI measures.

Natural Light vs Artificial Light CRI

As illustrated in the example above, our artificial light source (an LED lamp with 5000K CCT) does not produce the same redness in an apple as natural daylight (also 5000K CCT). This is due to the LED lamp having a different spectral composition than natural daylight, even though both light sources are the same 5000K white color. In particular, the LED lamp is lacking in red, so when the artificial light bounces off the apple, there is no red light to reflect.

As a result, the apple no longer has the same vibrant red appearance it had under natural daylight. CRI attempts to characterize this phenomenon by measuring the general accuracy of a variety of objects’ colors under a light source.

Natural Light vs Artificial Light CRI 02

Industries Where CRI Is Important

As previously mentioned, for the majority of indoor and commercial applications, the general baseline for acceptable color rending is 80 CRI and above. In industries where color appearance can have an effect on the work completed, or can contribute to improve aesthetics, 90 CRI and above is recommended.

Organizations where 90 CRI may be needed for professional reasons include hospitals, dentist offices, printing facilities, textile factories or paint shops. Areas where improved aesthetics could be important include high-end hotels, retail and grocery stores, residences, and photography studios.

CRI might not be important if you’re lighting a parking ramp, warehouse facility, or in an application where you don’t particularly care if the objects you’re viewing are in B&W or in color.

Questions About Lighting? Give EPL a Call

The team at Energy Performance Lighting understands the color rendering index and can answer any questions to help you make the best decision for your lighting needs. Give us a call at 608-661-5555 or send us a message – we’re more than happy to help! 

How Light Influences Body Chemistry

Chemically, the human body is performing several different functions at every second of the day – from breaking down food, to converting oxygen to CO2, to promoting chemical reactions (in the form of hormones) triggered by our senses. Two hormones that are driving factors in our day-to-day-lives, melatonin and cortisol, are affected by the amount of natural light (i.e. sunlight) we receive throughout the day. Light synchronizes our circadian rhythm or our "internal body clock", meaning light has more than just a visual impact; it supports bodily functions 24 hours a day. This internal clock must be recalibrated each day by sunlight.

The Hidden Photoreceptor

In the human eye, there are two visual photoreceptors, rods and cones, which are responsible for detecting light, objects and colors as they move through our vision; however, in 2002, there was a third photoreceptor of special ganglion cells discovered that do not have a visual function but are still photoreceptive. There are known as the ipRGC (intrinsically photosensitive Retinal Ganglion Cells).

Compared to rods and cones, the ipRGC are sluggish and more responsive to light over time. Their sole purpose is to register ambient light brightness and respond by regulating the body's biological processes according to the amount of light reaching the cells. Around one to three percent of ganglion cells are non-visual photoreceptors that contain a photosensitive protein known as melanopsin. The ipRGC and melanopsin work together to synchronize our internal clock. The photoreceptors of the human eye are particularly sensitive to blue light of the visible spectrum (with a wavelength around 480 nanometers). As a result, an influx of blue light can slow down the production of melatonin at night.

Daylight's Influence on the Human Body

Without receiving the full-spectrum and biochemical effects of daylight, our internal clock can fall out-of-sync resulting in tiredness, mood swings and a potentially weakened immune system. Our internal clocks also control complex biochemical processes, such as digestion, heart rate, and hormones. Melatonin and cortisol are two important hormones that are influenced by daylight and help to determine circadian rhythm by chemically-influencing the body in opposite cycles. The natural anti-depressant Serotonin also plays a role in circadian rhythm.

Melatonin

In the evening, our pineal gland produces melatonin, where its secretion is regulated by a rhythm-generating system located in the SCN (suprachiasmatic nucleus of the hypothalamus), which makes us feel tired, slows down bodily functions and other metabolic processes (such as body temperature) to help achieve of good night's rest. During this phase, our body also secretes growth hormones to aid in repairing cells at night.

Cortisol

Cortisol is a stress hormone produced in the adrenal cortex. It begins to elevate at about 3 a.m. and reaches a peak concentration around 9 a.m., steadily declining during the day. This hormone stimulates our metabolism and starts the body's processes for day-time operation. The initial daylight supresses the production of melatonin via the third photoreceptor in the eye.

As daylight fades, our internal clock switches back to "night mode". If there are any blue-light sources where a person is trying to sleep, such as a televsion, your cell phone, an alarm clock, or even street lights outside, there will be lower melatonin production (if any at all) resulting in bad sleep, waking up feeling unrested, fatigue during the day, and a lack of energy and motivation. This process can become more drastic as the winter months arrive, as some people develop seasonal affective disorder (or SAD). Their internal clock is missing its cues due to a faulty hormonal balance in the brain.

Finding Balance

When we don’t have the proper balance of light throughout the day, the chemistry of our body is out of sync, which can lead to physical and mental health risks. Uneven exposure to light and its effects on human health are often seen during winter months in areas moderately-to-extremely north or south of the equator. One negative effect many people suffer from, seasonal affective disorder (or SAD), causes people to feel unmotivated, tired, and depressed. With less bright-white light reaching their eyes, less cortisol is produced, therefore causing fewer stimulants in the body to promote the feeling of energy and happiness.

Understanding how light affects our circadian rhythm and the chemistry of our body, it becomes easier to understand how the correct type of lighting in homes, schools, hospitals, and prisons is crucial. In the correct lighting, students focus better in class, hospitals have more alert night staff, and prisons have fewer outbursts with inmates.

At Energy Performance Lighting, we’re dedicated to providing a healthier artificially-lit environment for everyone. Our focus is on the scientific connection between light and human health while delivering energy savings unmatched by any competitor. If you have any questions or you're curious how a lighting upgrade or lighting retrofits can benefit you, contact a certified lighting experts at EPL by phone at (608) 661-5555, send us a message or apply for no-cost facility assessment and an EPL team member will contact you within one business day.

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