Wall packs increase in size either for design purposes or to house higher lumen output systems. From a design perspective, luminaire size will depend on factors such as placement and other aesthetic concerns. Achieving higher wattage and lumen output is another reason to increase size to allow for larger lamps and ballasts and heat management systems. Also, more space inside the luminaire helps to reduce the effect of heat on the ballast or driver. Increased size may be achieved by making the overall fixture bigger or by adding a deeper box to the back of the luminaire. In cases where you are replacing older wall packs, the fixture may have left discoloration on the wall or may be smaller than the old one, so it’s important to get the same size or use an option such as a goof tray to hide the discolored surface.
2. Luminaire Performance
A key indicator of fixture performance is efficacy, which is calculated as lumens delivered / fixture wattage. It is a measure of the efficiency with which the fixture provides visible light from electricity. Given the advancements in today’s LED chips, a luminous efficacy of 100 lumens/watt is considered as par. So a 20W wall light should deliver about 2000 lumens on the ground. Some wall lights have reached efficiencies of 120 - 130 lumens/watt.
LED equivalency is another factor to think about. While there is no defined science to say which equivalent LED fixture replaces a traditional fixture, there are certain replacement estimates that manufacturers provide for wall lights based on lumen output, light distribution and the lighting application.
3. Light Distribution
Wall packs distribute light in one of three main ways. Standard wall packs focus the light out and down. Whereas up/down wall packs push the light both to the sky and to the ground. Wall lights are also useful for eliminating shadows in recessed areas of architecture. A traditional wall pack will emit
around 4,000 lumens using a 175 watt metal halide lamp. On the other hand, an LED wall pack can produce the same 4,000 lumens using on average 40 to 60 watts, depending on the luminaire and driver. Given that LEDs generally have better colour maintenance and longer life, the advantages are clear.
4. Colour Temperature
A number of factors go into deciding which colour temperature is right for your wall light. Aside from aesthetics, these considerations include: what is the purpose of the light, what light source will be used, which other lights are nearby, does the light have dark sky requirements and limitations due to neighboring properties. The advantage of LEDs over older light source technology is the flexibility of lumen output, colour maintenance and light colour choices.
5. Light Pollution
When choosing your wall packs, you should consider the three components of light pollution: light glare, light trespass, and sky glow. Light glare is the harsh, uncomfortable brightness that light fixtures sometimes produce. Light trespass is the amount of light that exceeds the boundaries of a given area, such as a floodlight that lights up a neighbor’s property. Sky glow is the amount of light emitted upwards that illuminates the night sky. Many regions require certain standards regarding light pollution, particularly if you are in a city or urban area where dark sky compliance is a concern. In these situations, wall packs should be partial or full cutoff, ensuring that light is emitted either downward or slightly forward.
6. Housing/ Construction
Outdoor fixtures need to be durable, as they will be subjected to the wet conditions and varying temperatures. A high quality wall pack housing shell should be made out of a resilient material such as cast aluminum. The case should be treated with a conversion coating to deter corrosion. Chromate conversion coatings work extremely well with extruded aluminum because the chromate passivates the aluminum. A finish coat should be applied to wall pack using a powder coating process which makes them more durable.
As discussed, certain types of fixtures have advantages for being more durable and lower maintenance. It is hard to beat the lifespan and durability of LEDs which despite higher costs make a compelling case for a choice as an outdoor wall light. Physical accessibility is important since some fixtures require lift devices, industrial plants may need to wait for plant shut-down periods. Also cleaning lenses will improve efficacy so the fixtures need to be accessible.
As with other lighting products, wall packs are generally rated for the application they are designed for. The three major certifications are UL, ETL and CSA. UL is Underwriters Laboratories Inc. CSA stands for Canadian Standards Association. ETL originally was the marking for ETL Testing Laboratories and now is a mark of Intertek Testing Services. The wall pack should be rated by one of the three for wet location as the fixture will be used outdoors and may be exposed to driving rain.
9. Electrical Components
A wide range of electrical components may be used in luminaires today and it’s important to understand the quality and implication of choosing certain components. Low cost components might bring down the overall cost of a luminaire, but this brings long term implications such as potential component failure which may require more maintenance and higher costs over time. It’s important to understand the differences in key components such as drivers, ballasts and transformers, taking into account warranties.
10. Mounting Height
Mounting height is an importing consideration when selecting a wall pack, since the higher the fixture, the more lumens are required to maintain light consistency. While it may be true generally that higher watt fixtures deliver more lumens, advances in LED technology have produced lower wattage fixtures with higher lumens and higher efficacy. Another consideration is whether the fixture is being used on a new build or a retrofit project. In a new build, you can plan for the placement of the fixture according to lumen requirements, however in a retrofit the mounting height might be fixed based on pre-existing wiring, making it important to select a fixture that will deliver the required lumens for the space.
We have covered just some of the factors to consider in selecting your outdoor wall lights. Other considerations might include application, for example is the light for security or aesthetics; how long will the light be on each day; what rebates are available; what controls, photocells, sensors etc. will be used.
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