There was a study done by the Myth Busters a number of years ago that studied the myth about turning off lights.
The myth focused on the surge of electricity that takes place when we turn lights on and off. To summarize many people believe that the surge of energy is so great that it is not worth turning off lights when the room is unoccupied. The myth was busted. Yes, there is a small surge of energy, but the payback is 23 seconds. If you are gone from your room longer then 23 seconds it pays to turn off your lights.
I wanted to focus this article on the importance of making smart decisions with lighting. I am not a lighting firm, point being I am not trying to sell you a service or product in this article. My hope is to give you advice from a neutral third party.
Lighting is a very big part of our daily decisions, yet we do not give it much thought. If we were to break down the average building electrical use, lighting would make up about 15-20 percent. I would increase that percentage for churches. It is a big part of our worship services, depending on the church of course. However there are a number of ways we can impact our lighting use through little or no cost. Before I break down practical examples I wanted to share a quick example. I was performing an energy audit of a 500,000 square foot facility that had an annual electric cost of $1.2 million. This facility, a museum, is open to the public only about 6 to 8 hours a day, however their lights were on for 18 hours a day. Lighting in a museum is vital to artwork, suffice to say their lighting load was significant, and made up about 25 percent of their electrical use.
If all the facility did were modify lighting hours (meaning no investment) then they would save over fifty percent on their total electric costs. This equates to over $150,000 by simply changing behavior. This is an extreme example and there are a number of factors I left out of this equation, but the fact remains—managing our lighting load makes a very big difference.
- Turn them off If you are gone from anywhere longer then 23 seconds you're your lights off. It makes a difference.
- De-Lamp According to the IESNA, certain areas like hallways, classrooms, worships areas, common areas and more require a certain footcandle (a way to measure light output), however the average facility keeps these facilities over lit. We highly recommend de-lamping areas that are over lit. For example a church office might have 4 4-lamp linear fluorescents (T8) fixtures that measure over 100 footcandles. According to the IESNA offices should range from 30-50. In such a case the church could de-lamp each fixture from 2-4 lamps, or turn off two of the fixtures.
- Daylight I performed an audit at a large Houston church last week. The hallway had a large window covering the length of the corridor that allowed outside light (ambient light) to brighten the area. The lights in the hallway were also on, but did not provide an increase in footcandles due to the ambient light. We would either recommend adding a photocell to these lights or disengage during daylight hours.
- Switching or dimming In many offices and classrooms, switching allows a user to use all or half the lights. In these cases we recommend using half-lights when possible.
- Lamps When convenient use a desk lamp (preferably with LED bulb) opposed to turning on the office lights.
I will write a separate article on LED lamps, but I am a big proponent. LED bulbs use minimal wattage (8 watts opposed to 60 watts) and last 5-10x the life of incandescent.