Condo Media - April 2012 - 12

MAINE N e w s

by Jack Carr, P.E., RS, LEED-AP

R e g i o n a l

Consider a Light Diet
Technology Curbs Energy Cravings
ommercial building owners and condominium boards are looking at advances in indoor and outdoor light management to learn how it might not only save money, but also enhance the environment for their complex. Some improvements have been amazing, but why should we be surprised as much of the lighting technology found in many buildings has been around since we last used typewriters?

C A I

Bulbs and Fixtures
Most of us are familiar with compact fluorescent lamps (CFLs). They are rapidly replacing incandescent bulbs as they use 75 percent less energy than a standard bulb and last up to 10 times longer. Replacing a 100watt standard bulb with a 32-watt CFL can save $30 over the life of the bulb. But what about those ceilingmounted, standard fluorescent lamps, the most common being the 1.5-inch diameter “T12” lamp? Wise facility managers are converting to new “T8” (one-inch diameter) or “T5” (5/8inch diameter) lamps to reap the benefits of less energy consumption, higher intensity and longer life. It should be noted T5 lamps are not the same length as either the T12 or T8, requiring the entire fixture to be replaced. Thus, T8 lamps are the more poplar upgrade. But don’t stop at the new fluorescent lamps. Change the ballasts, too. The old lamps used “magnetic ballasts.” They are apparent when the lamps get old and the lamps fade and flicker. Replacing the old ballast with an “electronic ballast” provides not only flicker-free operation, but also energy savings of up to 30 percent.

And don’t forget the simplest upgrade: clean the fixture’s reflective surfaces to improve optical efficiency or change the lenses or louvers to acrylic diffusers to replace the current polystyrene diffusers that discolor from ultraviolet radiation. Condos with parking lot pole-mounted fixtures or garage ceiling light fixtures often use High-Intensity Discharge (HID) lamps, frequently the inefficient mercury vapor type. Like a fluorescent lamp, mercury vapor fixtures require ballasts with harmful substances such as PCBs (polychlorinated biphenyls). Other old fixtures to consider replacing are high-pressure sodium (HPS) fixtures. A typical upgrade would be to convert to white light, metal-halide (M-H) fixtures. If you have standard M-H fixtures, you can upgrade to the white-light M-D lamps allowing the retention of the old fixture by installing a pulse-start (PS) system. This will also require the replacement with PS-type ballasts and starters. We should not forget about exit lights that burn constantly using incandescent bulbs and always seem to burn out, compromising safety and security. The solution is the light–emitting diode (LED), which virtually never burns out. The alternative is the special retro-fit exit lamps that can burn up to 10,000 hours, compared to incandescent lamps that burn only 3,000 hours.

Motion Sensors
Another important energy savings device is the motion sensor. This was first developed for security applications, but has become widely used for commercial buildings as lighting can amount to over 40 percent of elec-

tricity costs. Motion sensors can replace wall-mounted switches or be used with them to allow an override function. The most common motion sensors are the Passive Infrared (PIR) Occupancy and the Active Ultrasonic Occupancy sensor. The PIR sensor monitors and detects significant changes in background heat energy. They are calibrated to detect “human” heat on a direct line-of-sight basis to turn on the lights with the presence of an occupant. When the heat source is not detected, the lights will turn off. Active Ultrasonic Occupancy sensors broadcast a high-frequency sound throughout the room that is undetectable by human ears. Any movement in the room will be sensed, the fixture is put into the occupied mode and the lights turn on. Lack of motion will turn lights off, which can be dangerous, so some designs include a dual technology of using both PIR and Active Ultrasonic. To extend energy savings further, some sensors have a daylight override mode that sense when the room has sufficient natural daylight and turn off the fixtures to avoid wasting unneeded artificial light. Many devices are not suitable for all applications, such as hallways used as a means of egress. There are sensors for this application and your lighting professional can provide guidance. With this information, you can shed energy costs and stay on a conservation diet that will not turn you off. CM Jack Carr, P.E., RS, LEED-AP, is senior vice president with CriteriumEngineers in Portland, Maine. He is a member of the Condo Media board and a frequent author and speaker.

CONDO MEDIA • APRIL 2012

Condo Media - April 2012

Table of Contents for the Digital Edition of Condo Media - April 2012