ACRA has gathered a team of local professionals dedicated to offering practical energy saving solutions for your home or business using the U.S. Green Building Council’s LEED rating system and our personal experience.
ACRA Electric knows there is much yet to learn in the way of energy efficiency and improving the outlook for our environment, so we are continually seeking to learn more. We conduct tests of the popular “green” technologies, making an effort to discover and dispel any myths which could mislead our customers.
We are committed to reducing our carbon footprint by recycling in our office and homes.
July 29th, 2010
An Energy Saving Success Story at Cape Harbour
Cape Harbour, a beautiful waterfront mixed-use development in Southwest Cape Coral, includes upscale homes, great restaurants and stores, and an in-water and dry storage marina. Additionally, Cape Harbour draws accolades with its two magnificent 15 story condominium towers. Each of these towers contain four floors of parking with the first two floors dedicated to public use and the third and fourth floors reserved for the building occupants’ use.
When the buildings were designed and built in 2005-2006, the lighting system for the parking garages consisted of 260 – 175 Watt Metal Halide fixtures designed specifically for parking garages. All fixtures were wired to remain on 24 hours per day. With an average rated 15,000 hour life expectancy, which translates to about two years, lamp replacement and fixture maintenance became a huge expense as the building began to age.
In the time since the buildings were built, there has been a revolution in the electrical industry. Many new types of energy saving green technologies have emerged, including occupancy sensors, light harvesting, solar voltaic panels, LED, and induction lighting systems, to name a few. We feel that our job in this revolution is to evaluate the different options available and recommend practical common sense solutions that will provide energy savings without sacrificing safety, while still being affordable and reliable. In this spirit, we were tasked with designing and installing a new lighting system for the parking garages.
The first question we asked is, “why do all of the lights need to be on 24 hours a day?” Openings around the perimeter of the garages provide plenty of natural light during daylight hours. After examining the construction documents, we realized the existing circuitry would allow us to separately control the perimeter row of fixtures with a contactor and photocell. This allowed us to keep the core area’s fixtures on while automatically turning perimeter fixtures off during daylight, providing immediate savings in both energy and maintenance.
The next step involved the selection and replacement of the 260 fixtures. Our initial idea was to re-use the existing fixtures with retrofit fluorescent or induction lamps, but this option proved to be impractical. We also considered many different LED options, some of which performed very well on the basis of photometrics and long life, but this option was cost prohibitive.
We finally chose a new fluorescent fixture with two T8 high performance lamps, a high efficiency electronic ballast, and a specular aluminum reflector. The lamps have a 30,000 hour rated life, and the ballasts have a five year warranty. After confirming that the photometric performance of the new fixtures would meet the requirements of the Florida Building Code, we performed calculations to determine the energy savings.
Based on $0.10 per KWH energy cost, the original fixtures cost $48,200.00 per year to operate. The new fixtures combined with shutting off the perimeter fixtures by photocell consume only $12,700.00 per year, a 73% savings. The payback for the installation of the new fixtures would occur in less than 1.5 years, not even including the savings from reduced maintenance! In fact, replacement fluorescent lamps and ballasts cost far less than the Metal Halide equivalents, so ongoing maintenance should result in significant savings as well.
The retrofit project is now complete, the old fixtures have been recycled, and the Marina South Tower parking garages have a new energy efficient and environmentally friendly “Green” lighting system.
Please contact us if you would like an energy survey performed at your facility to see if a lighting conversion makes sense for you.