Cleaning & Maintenance Management Online
November 2012 Feature 2

Learn To Shine The Light When Necessary

With the extravagant cost of electricity, facilities need to rethink when and how they light rooms not constantly in use.

November 6, 2012

All facilities have a few things in common beyond the obvious walls, floors and roofs.

Many facilities either serve multiple purposes, or they house differing amounts of people throughout the day.

What all facilities, be them public or private, also have in common is a restroom.

Empty RestroomPrivate residences, depending on their size, have one, two or more bathrooms, while public buildings like schools, airports, conference centers and everything else on down the line can have more restrooms than you can count.

All bathrooms and restrooms, no matter the type of facility they reside in, have one commonality: They need to be lit.

The frequency and duration for which each individual restroom needs to be lit will always differ from facility to facility, but there will rarely be a time when complete darkness is acceptable.

Unless, of course, if the restroom is not in use.

No restroom will be in use 24 hours a day, seven days a week; there is a large chunk of time that, if employing regular lighting, a facility is straining its electricity budget for no reason.

The toilets, sinks and mirrors do not need the light; they will get along just fine without it.

With the cost of electricity being one of the biggest pieces of any facility’s budget, and with economic times as in flux as they have been in recent years, it is important that facilities do everything they can to ensure they’re not flushing away good money.

High Usage

Because every facility is different, estimates on exactly how much of a building’s energy budget is taken up by lighting vary from anywhere between 20 and 40 percent.

Even the low end of the spectrum is a significant amount.LED Bulb

Variation can come from a number of factors, including building size and frequency of use.

With the economy still in an uncertain place, number-crunchers are pressed to find savings to the company bottom line wherever they can.

In fact, an overlooked area of savings rests within the nuisances of the electric bill.

A facility’s restrooms are often unoccupied for large spans of time, which means that the lights are essentially left on for no one, or just in case someone decides to use the facilities.

Leaving these lights on all the time can contribute to the high drain of electricity on the facility as a whole.

While it might seem like this is a never ending problem, there is a solution: Motion sensors.

A No-brainer

Once you think about it, the idea of motion sensors as a means to an economic end is really a no-brainer.

Motion sensor lights might already be employed in other places outside a facility, for security measures, but why should this technology be relegated to the periphery of a building when it can do just as much good inside?

Where motion sensors in security lighting are intended to turn on in order to scare off any would-be intruders and alert those in charge or on guard of their presence, lighting with motion sensors in rooms that aren’t used at a constant rate are intended to go off.

When the restroom is not occupied for a certain amount of time, which can be set to a specific period, the lights in the restroom will turn off.

The next time the sensor detects any sort of movement, the lights will turn back on.

How It WorksLighting Motion Sensor 2

In technical terms, the “motion sensing” feature on most lights is typically a passive system that is used to detect infrared energy.

Therefore, the sensors in a motion sensing lighting unit are known as passive infrared (PIR) detectors or “pyroelectric sensors.”

In order to make a sensor that can detect the motion of a human, the sensor must be sensitive to the temperature of a human body.

Humans, having a dermal temperature of about 93 degrees Fahrenheit, radiate infrared energy with a wavelength between nine and 10 micrometers.

Therefore, the sensors are typically sensitive in the range of 8 to 12 micrometers.

It doesn’t take a lot of movement for the sensors to detect that someone has entered and is moving about the room; however, if the interval after which the lights are set to turn off is too short, patrons who need a little extra time might suddenly find themselves in the dark.

The sensor is sensitive to motion, but not to a person who is sitting or standing still because the electronic component of the sensor is searching for a rapid change in the amount of infrared energy it is detecting.

A person walking into the room gives the sensor what it is looking for to switch the lights back on; a stationary individual does not.

In offices that have motion sensors employed, this doesn’t often pose too much of a problem, as the occupant is generally close enough to the sensor to trip it again.

MoneyRestroom occupants who are busy or otherwise indisposed might not have such luxuries, making it of great importance to ensure that there are sensors placed in areas that occupants can trigger with the simple wave of a hand, or set the "lights-out" timer to a decent interval.

Significant Savings

Wasting energy makes as much sense as wasting money.

With the state of the economy and the ever present worry that the Earth’s natural resources, which we depend on to power almost everything, may not always be something we can count on, we all need to do our part.

The simple solution of installing a motion sensor that can, without anyone else needing to think about it, regulate the usage of electricity in restrooms makes good financial sense.

And, it will help your facility operate in a manner that is more green and sustainable, two things that need to be on everyone’s mind in order to lessen the impact we have on the Earth.



Types Of Technologies

There are a number of different occupancy sensor technologies from which to choose.EPA EPP certification

The right type of technology, given a building's size and usage, will differ from facility to facility.

The following are a selection of technologies as outlined in the U.S. Environmental Protection Agency's (EPA) Focus on Energy report:

  • Passive infrared (PIR) occupancy sensors: Infrared sensors detect the difference in heat emitted by humans in motion from heat emitted by the background space
  • Ultrasonic occupancy sensors: Ultrasonic sensors emit a high-frequency signal that is undetectable by humans and animals, which bounces off objects, surfaces and people in a space; it then returns to the sensor, which interprets change in the frequency as motion
  • Dual-technology sensors: Dual-technology sensors employ both PIR and ultrasonic technologies for maximum coverage and reliability with fewer false triggers because these sensors activate lights only when both technologies detect movement.


Space Type

Savings Potential

Private Offices

13 to15 percent

Conference Rooms

22 to 65 percent

Classrooms

40 to 46 percent

Restrooms

30 to 90 percent

Corridors

30 to 80 percent

Storage Areas

45 to 80 percent

Information is from the 2009 U.S. Environmental Protection Agency (EPA) Focus on Energy report.