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Lighting Reference Guide – Applications

4 Applications

a. Lighting Project Management

The objective of a “quality” lighting design is to provide a safe and productive environment – whether for business or pleasure. This is accomplished by a redesign or upgrade to ensure that the appropriate quality and quantity of light is provided for the users of the space, at the lowest operating and maintenance cost.

A “quality” lighting design addresses more than ‘first cost’ issues. Either Net Present Value (NPV) or the Internal Rate of Return (IRR) can properly evaluate life cycle costs.

Proper evaluation of the data, planning and execution are essential for successful implementation. Building systems are inter–related. For example, removing 10 kWh of lighting energy from a commercial building will have a significant impact on the heating, ventilation air conditioning system. Cooling cost will be reduced, but replacement heating may be required. It is necessary for the lighting designer to have a clear understanding of all the building systems and how they interrelate.

Typical ‘lowest (first cost)’ projects save energy, but they usually do not maximize the saving potential in the building. This can result in a ‘re–lamping’ exercise that provides a 10 to 30% savings, but prevents a lighting designer from returning to the project to maximize savings at a later date.Valuable energy reductions are sacrificed.

For example, in a commercial building in Toronto, the original scope of work would have resulted in electrical lighting savings of 37%, which on the surface would appear to be a respectable objective. However, a lighting designer was retained and a comprehensive design solution was provided. The project achieved:

  • lighting energy savings of 63%;
  • reduced payback;
  • Internal Rate of Return of more than 30%; and
  • solutions for related building issues such as maintenance, end of fixture life, etc.

The ‘first cost’ was higher, however the life cycle cost as calculated using either the Net Present Value or the Internal Rate of Return proved a significantly superior solution.

b. Evaluation Methods

The methodology used to evaluate the energy savings for a lighting project, either for a retrofit or a comparison for new projects, is critical to the success of installing a complete energy efficient solution. Too often the simple payback method is used which undervalues the financial benefit to the organization. Following are brief descriptions of the various payback evaluation methods. It is important that the choice of method reflects the same principles the company uses when evaluating other capital investments.

Life Cycle Costing

A proper life cycle costing analysis will provide a more realistic financial picture of an energy retrofit project than a simple payback evaluation. Unfortunately, energy efficiency has been a low priority and for convenience, the ‘Simple Payback’ analysis is often used to evaluate energy projects, particularly for lighting projects.

  • Simple Payback consists of the project capital cost divided by the annual energy savings realized. The result is the number of years it takes for the savings to pay for the initial investment, e.g.; $100,000 project that saves $35,000 annually has a three–year payback.
  • Life Cycle Costing analysis is a similar calculation, however, it looks at a realistic timeline and includes the maintenance cost savings, the potential increased cost of replacement lamps, and the cost of money, and can only be properly evaluated by considering the cost of money by either the Internal Rate of Return, or the Net Present Value, as discussed below.

Discounted Cash Flow

Discounted cash flow methods recognize the time value of money and at the same time provide for full recovery of investment in depreciable assets.

  • The Net Present Value method discounts the stream of annual savings by the company’s required return on investment or Cost of Capital.
  • The Internal Rate of Return method finds the discount rate, which matches the cash inflows, and the cash outflows leaving a Net Present Value of zero. A company can then make capital investment decisions based on the projects that have the highest Internal Rate of Return; e.g., with interest rates below 10%, a project that delivers an IRR above 10% creates a positive cash flow.

c. Lightning Levels

Light level, or more correctly, Illuminance Level, is easily measured using an illuminance meter. Illuminance is the light energy striking a surface. It is measured in lux (SI) or foot candles (Imperial). The IESNA (Illuminating Engineering Society of North America) publishes tables of recommended illuminance levels for all possible tasks. It is important to realize that the illuminance level has no relevance to the lighting quality; in other words, it is entirely possible to have the recommended illuminance in a space but with a light source that produces so much glare that it is impossible to work. This accounts for many of the complaints of either too much or not enough light.

d. Light and the Environment

There are a number of methods for determining whether a lighting installation is efficient. One method is for the lighting designer to check with the current version of the ASHRAE/IESNA 90.1 lighting standard. This document, which is revised regularly, provides a recommendation for the Lighting Power Density or watts per square meter or square foot attributable to lighting. It is usually possible for a capable lighting designer to achieve better results than the ASHRAE/IESNA 90.1 recommendations.

e. Technology Integration

While this handbook is divided into sections dealing with individual lighting technologies, it is essential to realize that the best lighting measures combine technologies to maximize the efficiency of systems. Experienced lighting designers will, for example, select the fluorescent ballast Power Factor, the lamp, and the control system that provide the best possible results for the particular environment and client objectives.

The best solution is a derived by matching client requirements with the technology. Therefore, one application may use T–5 technology while another uses metal halide.

f. Case Studies

The following are three case study examples

Case Study One

A School Board Project in Ontario.

School boards are usually the owners of their facilities, similar to municipalities, universities, schools and hospitals, i.e., the MUSH sector. In reaction to the baby boom in the mid sixties there was a tremendous expansion in the construction of facilities for this sector. Thus, facility managers have inherited 45–year–old facilities, with much of the infrastructure needing replacement.

This is particularly true for schools. There are limited funds for replacement, so upgrading the systems in these facilities is often the only option.

Lighting systems, just like furnaces, chillers, motors and pumps, are part of the 45–year–old facilities and have a defined life span. Over time, lamp sockets and internal wiring deteriorate, lenses become cracked and broken. Therefore, at some point it is more economical to replace rather than to continue to repair.

Another significant concern for the facility manager is change in use. Computers were unheard of in primary and secondary education when these facilities were constructed, but they are now in common use both in the classroom and for facility management. Curriculums have also evolved, and some facilities, such as science labs, now have very different uses. As a result, there are many classrooms where the lighting technology is out–dated, the equipment is due for replacement, and the light fixtures are no longer appropriate for the illumination of the task.

Lighting technology changes lead to more choice. School gymnasia provide a good example. Older schools may have incandescent, fluorescent or mercury vapour lighting in their gyms. In these facilities 50% or more of the energy in the gymnasium can be saved by redesigning the space with more efficient fluorescent systems using T8 or T5 lamps, combined with occupancy sensors. Some school boards prefer to use metal halide high bay fixtures because fewer fixtures are required, meaning lower maintenance costs. These fixtures can be specified with ‘high–low’ ballasts combined with occupancy sensors for additional savings.

Situation:   This project consisted of a survey of 130 building evaluations, including administration, secondary and elementary schools. The challenge in most school board projects is the relatively low hours of building use compared to commercial projects.

Area:   5,750,000 square feet

Action:   A company specializing in the design and delivery of energy programs retained a lighting specialist to help the school board provide a full assessment of savings and costs to achieve a comprehensive energy project.

Technology:   Existing lighting throughout the 130 buildings consisted of 34 W T12 lamp fluorescent fixtures, some mercury vapour fixtures in gymnasiums, and incandescent exit signs and decorative lighting.

Solutions:   The design team specified a comprehensive approach including lighting upgrades and redesign, lighting controls, building automation, fuel change, envelope improvements, HVAC upgrades, and solar panels.

  • In the classrooms, the fluorescent fixtures were upgraded to T8 fluorescent systems with electronic ballasts, and where appropriate, replaced with new, more efficient fixtures. Where the patterns of use made it economical, occupancy sensors were installed.

  • In the washrooms the existing systems were replaced or retrofit to T8 lamps with electronic ballasts. Occupancy sensors were installed where appropriate.

  • In the gymnasia, most locations received new luminaires, either T8 fluorescent or metal halide high bay fixtures. Occupancy sensors were installed where appropriate.

  • In offices, the fluorescent fixtures were upgraded to T8 fluorescent systems with electronic ballasts, and where appropriate, replaced with new, more efficient fixtures. Where the patterns of use made it economical, occupancy sensors were installed.

  • Exit signs were replaced with new Light Emitting Diode (LED) exit signs.

  • Outdoor lighting systems were upgraded with new controls, using timers and in some cases, photocells, and new luminaires were installed with high pressure sodium lamps.

Results:   Total Project Cost: $12,000,000


21.9 million ekWh (equivalent kilowatt hours)

Cost Savings: 
$1,500,000 per year
Internal Rate Return greater than 11%.
Note: The owner included other measures that provided better results and still exceeded their hurdle rate.

Measures:  Lighting retrofit, fuel change, building automation system, envelope improvements, HVAC upgrades, solar panels.

Case Study Two

A Commercial Building in Downtown Toronto.

Commercial property managers are constantly looking for opportunities to enhance tenant comfort and decrease costs. Lighting is considered a proven technology that meets both objectives.

Commercial buildings commonly use variations on the fluorescent solution. There are a number of issues for the lighting designer to consider. The lighting layout, the arrangement and geometry of light fixtures, may no longer suit the location of work stations. The light levels may be too high for use in computer environments. The light fixtures may have lenses which create reflections on computer screens. The controls are often limited to circuit beakers in an electrical room on each floor. The use of 347 V systems in Canada can also limit the options available to the lighting designer.

A major consideration for building owners and tenants is the disruption caused by a lighting project. Issues requiring substantial cooperation and coordination include:

  • access to secure floors or rooms,
  • elevator access,
  • storage of tools and equipment,
  • disposal of packaging materials,
  • clean–up at the start and end of each shift.

In order to expedite a project in a timely manner with a minimum of disruption for tenants, skilled project management is required. Obtaining spot energy consumption measurements for both ‘pre’ and ‘post’ conditions are recommended.

Situation:   This project was for a Class A building in Toronto, with 35,000 existing ‘base building’ luminaires.

Area: 2,670,000 square feet

Action:   The building owner hired an engineering firm specializing in energy–efficient systems to provide a cost analysis for retrofitting existing lighting systems with more efficient T8 lighting systems.

Technology:   Existing base building light fixtures were an inefficient design which used a costly ‘U – Tube’ fluorescent lamp. Each fixture contained 3 lamps and 2 electromagnetic ballasts.

Solutions:   The lighting designers provided a redesign of the fixture incorporating a reflector, an electronic ballast and linear T8 lamps. On–site testing proved that light level requirements were met and that a savings of 63% of the lighting energy compared to the existing system. This solution also avoided the cost premium of the ‘U – Tube’ lamps.

  Other measures undertaken as part of the overall program included boiler replacement, fresh air improvements, and water measures. This project shows the value of integrating measures. For example, 3,500 kW of lighting load was removed from the building, as well as the resulting heat. This created significant cooling savings but also made boiler upgrades essential. Modern, more efficient boilers and controls replaced the required heat with substantial savings, and provided improvements to indoor air quality.


Total Project Cost: $17,000,000


19.4 million ekWh (equivalent kilowatt hours)

$1,800,000 per year

Internal Rate Return greater than 10% (Note: the owner included other measures that provided better results and still exceeded their hurdle rate.)

The 3,500 kW reduction translated to about a $1 million annual saving, and the lighting project cost was about $2.5 million; an internal rate of return of 30%. As is usually the case with these projects, the owner bundled other measures with significantly longer paybacks into this project to maximize the improvements to the building and to better accommodate ‘required’ system upgrades such as the new boilers.

Case Study Three


Situation:   An industrial facility in southern Ontario was receiving increased complaints and concerns about existing light levels. Operators were finding poor light levels an increasing concern in certain areas. In addition, there were unusually high maintenance costs due to annual lamp replacements attributed to the plant having a dusty environment.

Action:   An industrial lighting designer was retained to tour the facility, interview staff and suggest potential options.

Technology:   Typical two lamp 34 W, T–12 open fixture fluorescent fixtures were in use throughout the plant as per the original installation in a standard ‘grid’ pattern. Although changes had occurred in the plant over the years, the lighting remained the same. Light levels in some areas had deteriorated to as low as 5 foot candles, compared to IESNA recommended 15 foot candles. Staff was concerned and offered to demonstrate the challenges of operating equipment in constraint areas

Solutions:   A three phase solution was proposed and accepted.

Phase 1:   A short 15 page preliminary assessment was prepared to summarize the data on the existing situation including light levels, estimated lighting fixtures, lamp, ballast and fixture types, as well as recommended options.

Phase 2:   Because there were other plants with similar opportunities, it was decided to arrange a tour so staff could see similar industries that had installed, and operated with, the proposed technologies; e.g.,

  • Metal halide
• Low pressure sodium
T–8 fluorescents

Phase 3:   A demonstration pilot project was selected for the recommended option to confirm staff acceptance, light levels and recommendations. A design level of 20 foot candles was specified to offset loss of light output due to:

  • coefficient of utilization (CU),
• lamp lumen depreciation factor (LLD), and
• luminaire dirt depreciation factor (LDD).

  The reflectance in the test area was considered zero because of the dirty environment. There was no prior experience in modeling this type of space due the complexities of the structures and type of work for maintenance, so flexibility was rated very high.

  The test area called for 27 metal halide 400 W fixtures and was increased to 32 at the request of plant staff.

  The pilot demonstrated a 36% IRR, to exceed the plant internal hurdle rate of 14%. Light levels went from 5 fc to 18 fc and 20 fc in the pilot areas, lamps were reduced from 256 W to 32 W with a 30% energy saving.

Results:   Metal Halide 400 W enclosed fixtures were selected and provided the following results:

  • 31% energy savings
• 51% fixture and ballast reduction
• 75% reduction in lamps
• four times more light.
• 100% client satisfaction with quantity and quality of light!

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