By David Poole
In a program involving 13 hospital parkades in Calgary and Red Deer, Alberta Health Services (AHS) upgraded old HID lighting to LED technology, creating an annual cost savings of almost $250,000, while bringing light levels to current standards, and improving the overall quality of illumination.
Illumination in many covered or underground hospital parking lots in Alberta is provided by a mixture of HID (High Intensity Discharge – typically metal halide or high pressure sodium) and fluorescent T8 lighting. Lighting levels varied greatly, from very dim in some cases, to illuminated well beyond current standards for parkade lighting in others. In a retrofit and redesign program, funded by AHS Parking Services department, thirteen parkades were selected for a change-over to LED lighting technology. It should be noted that AHS Parking Services is an ancillary operation and is committed to providing an operation that is sustainable, effective and efficient. With this in mind, the project included a redesign of the lighting, and the use of motion and ambient daylight sensors in order to provide adequate light at all times and further reduce energy consumption and costs.
Alberta Health Services engaged a lighting consultant to provide tender documents for the upgraded lighting system and provide pre and post electrical measurements in order to verify the savings. The consultant utilized the current Illuminating Engineering Society of North America (IESNA) recommendations to redesign the parkade lighting. The lighting consultant and AHS worked together to evaluate a number of LED lighting products in order to provide an acceptable number of approved products based on a number of factors including performance, quality, warranty, history, etc.
A total of 4895 fixtures were affected by this project. The simplest upgrade consisted of replacing existing fluorescent T8 tubes with LED tubes of equal length but reduced wattage, using the existing fixtures and ballasts. For the most part, the work involved replacement of existing fixtures with new LED fixtures with integral motion and daylight sensors. A dimming feature on most fixtures allowed a reduction of light levels to a set percentage (30% in most cases) when no one is driving or walking in the immediate vicinity. A mix of pendant fixtures, strip lights, wall packs, canopy and surface mounted fixtures were used to serve the needs of the various areas (parking areas, stairwells, elevator areas, walkways, etc.). Before and after light level readings were also taken, as a way to demonstrate compliance with IESNA standards.
The savings achieved have been determined by pre and post-project logging of energy consumption data using DENT data loggers. Savings vary between 23% and 90%, with an average of 68% across all parkades. The low end of the savings spectrum was achieved with the one-for-one replacement of fluorescent by LED tubes. A contributing factor to the low number is the fact that the partially open parkade already had daylight and motion sensors, which reduced the number of hours that the lights were on. The high-end savings were achieved in a parkade which was very bright initially. Furthermore, this particular parkade is used by staff, creating shorter periods of activity during shift changes, followed by long periods when nothing is moving, so the lights dimmed to the reduced output (and energy consumption) setting.
The simple payback period for the entire program is slightly over 10 years. Already, over the course of the implementation of the program, prices of LED fixtures have come down and light output per Watt have gone up. Future retrofits should show even better returns. An added benefit, which is not included in the pay-back calculation, is the expected long life of the LED fixtures and the reduction in maintenance costs for replacing lights and ballasts.
As a result of the project, Alberta Health Services avoids the emission of approximately 1,800 ton of CO2e greenhouse gas emissions every year.
Whenever changes are made that directly impact users, feedback can be expected. In a few cases, users complained about lower lighting levels (as indicated, a few parkades were illuminated well above current standards), and in a limited number of cases, users expressed feeling unsafe. The project team responded to complaints by investigating the individual situations, and adding some lights where complaints were found to be legitimate.
An important lesson learned during the work at the first parkade is to not remove all old lighting before the new lighting is operational. Leaving some of the old lights up eases the transition to the new lighting regime for users. We also learned that communication could have been improved, through signage and other means, informing users about the goals and duration of the project, and the functioning of the lights (explaining the dimming and the day-light sensing features). Furthermore, including representatives from users like unionized staff and protective services to point out possible concerns about light levels in general or known dark areas from the onset, may facilitate easier acceptance of inconveniences during construction and acceptance of the final result.
Substantial energy cost savings can be achieved by changing parkade lighting to LED lighting technology, depending on factors like current lighting technology, existing light levels, and the amount and nature of traffic in the parkade. Reduction in costs of lighting technology and improvement in efficacy will result in faster payback periods in the future. Reduced maintenance costs will help to reduce potential rate increases and are an important factor to consider in the overall project economics. Communication with stakeholders is important to ensure smooth project implementation and acceptance of the changes. ν
Alberta Health Services is the provincial health authority responsible for planning and delivering health supports and services for more than four million adults and children living in Alberta. Its mission is to provide a patient-focused, quality health system that is accessible and sustainable for all Albertans. AHS Parking Services currently manages over 8,000 patient/visitor stalls and over 28,000 staff stalls in 31 parking structures and various leased and owned surface lots located in 9 municipalities throughout the province. As an ancillary operation, Parking Services must operate as a self-sustaining program. No government provided health care dollars can be used to build, lease, maintain or administer parking services at site where parking charges exist. All parking-related costs must be fully recovered through fees collected from users
of the service.