THE COMPLETE GUIDE TO OUTDOOR WALL LIGHTS

Transcription

1 THE COMPLETE GUIDE TO OUTDOOR WALL LIGHTS

2 CONTENTS 1. INTRODUCTION 2. TYPES OF OUTDOOR WALL LIGHTS 3. LIGHT SOURCES IN OUTDOOR WALL LIGHTS 4. FACTORS IN SELECTING OUTDOOR WALL LIGHTS 5. SUMMARY lighting glossary rabdesign.ca 2

3 INTRODUCTION Wall lights are used to light walkways, entrances, pathways and around the perimeters of buildings. They mount on almost any vertical surface and function both for accent and area lighting as well as for safety and security. Otherwise known as wall packs or wall mounted lights, they may also be pole mounted. Wall lights are made both for outdoor and indoor usage, although commercial wall lights mostly have outdoor applications on the walls of warehouses, factories, schools, churches, office buildings and parking garages. Wall packs come with a range of light source technology and are designed to illuminate large areas and be able to withstand abuse from the elements including rain, sun and dirt. Traditionally wall lights use high intensity discharge (HID) or high pressure sodium lamps, most commonly a 175W MH or 70W HPS. However these fixtures are often inefficient, wasting a lot of the light produced by the lamp. Choosing the right outdoor light fixture involves evaluating the space to be lit, the size of fixture, energy consumption, cost and other variables. This e-book covers the main types of wall lights, the technology used in them and how to select the right wall light for your needs. lighting glossary rabdesign.ca 3

4 TYPES OF OUTDOOR WALL LIGHTS There are 5 main types of wall packs, each of which serve specific purposes and control light in different ways: traditional, semi-cutoff, full cutoff, adjustable and architectural. Standard or traditional wall packs distribute light out and down. Semi cutoff wall packs limit the light to mostly down. Full cutoff wall packs distribute light only down. Adjustable wall packs have a mechanism which allows the fixture to adjust the light in various directions. Architectural fixtures use light in different ways to accent, highlight features or add nuance to a structure. 1. Traditional Wall Packs: Traditional wall packs are the most frequently used as they are able to emit light farther out from the wall than other wall lights. They are often used as area lights that are wall mounted as opposed to being on a pole. As with most designs of wall packs, they come in different sizes to accommodate a range of wattages. Traditional wall packs are available with various light sources. Some common issues with standard wall packs are that they are not dark sky compliant. Since the light is not tightly controlled, the result is excess light trespass and unnecessary light pollution. 2. Semi-cutoff Wall Packs: Semi-cutoff wall packs are a combination between a standard wall pack and a full cutoff wall pack. The lamp in the fixture is shielded slightly by a top that comes down in front of the luminaire. While the effect limits some light pollution, it still does not make it dark sky compliant. Light is emitted everywhere, but less of the light goes up. Similar to a standard wall pack, the semi-cutoff is still effective as a wall mounted area light. Semi-cutoff wall packs are available with a range of light sources. lighting glossary rabdesign.ca 4

5 TYPES OF OUTDOOR WALL LIGHTS 3. Full Cutoff Wall Packs As described, full cutoff type wall packs are fully covered except at the bottom of the luminaire, forcing the light down. This tight control of the light makes it dark sky compliant. Full cutoff also means the light trespass is reduced if not eliminated in most instances. The lamp can t be seen other than from below the luminaire. The wall where the luminaire is mounted on is washed and only the area under the wall pack is illuminated. Typically, full cut off wall packs have visible conduit entries on the side and bottom. 4. Adjustable Wall Packs: Adjustable wall packs are those that offer some level of flexibility and adjustment of the fixture through a swivel like movement which is embedded in the fixture. These can be both full cutoff and semi-cutoff. Available in various sizes and light sources, including LED, these fixtures have adjustable heads and may include a photocell; they are often used to replace traditional wall packs and flood lights. The head may aimed straight for dark sky compliance, or aimed out if more light is required. 5. Architectural Wall Packs: Architectural wall packs are wall packs that don t fit typical categories. Instead of being built with a specific purpose, such as to be dark sky compliant, architectural wall packs are stylized to highlight or complement the architecture of a building or area. Many architectural wall packs are still dark sky compliant or can project light out, but are purchased for more than just a functional purpose. Typically, conduit and power entries are not visible so power cables enter from the back. lighting glossary rabdesign.ca 5

6 LIGHT SOURCES IN WALL PACKS Wall packs have traditionally come in metal halide (MH), high pressure sodium (HPS), compact fluorescent (CFL), induction and incandescent. All these and other variants are still in use depending on the need, but as in most lighting categories, wherever possible, LEDs are replacing the older technology. Below we cover the pros and cons of the dominant light sources used in wall packs. 6. LED LEDs are hard to beat for their energy efficiency, longer life span, low maintenance and flexibility. They can save over 80% of the energy cost and maintain the majority of their lumen output over a lifespan which could be more than 100,000 hours. LEDs are available in all the popular Kelvin colour temperatures to complement lighting already in place, including white. Color rendering (CRI) is typically 75 and above. Whereas metal halide and high pressure sodium lights blast in multiple directions and require reflectors for efficacy, LED wall packs are available in full cut off and standard distribution. 7. High Pressure Sodium High-pressure sodium lamps offer a very high lumen output at a low cost. Organizations with less concern about aesthetics or light quality might use HPS because of its lower cost, long lifespan of about 20,000-24,000 hours and also its high lumens per watt. HPS also performs well in the cold, which made it the go to choice for many years for outdoor fixtures such as streetlights and wall packs. HPS lamps emit a yellowish light and have a low colour rendering score of only 22, not ideal for security cameras. 8. Metal Halide Metal Halide lamps also offer a high lumen per watt output, making it another good choice for wall lights. Common applications for these lamps included outdoor areas such as parking lots, streetlights, stadiums and wall sport courts. MH lamps have a rated life of up to 15,000 hours and produce a white light typically 4700K with acceptable color rendition of 65 CRI. They also operate reliably in a wide range of temperatures and colours, such as blue and green. Compared to HPS, the more frequent maintenance of replacing lamps increases cost, but some organizations prefer it for the lighting glossary rabdesign.ca 6

7 LIGHT SOURCES IN WALL PACKS 9. Fluorescent Fluorescent lamp and ballasts (typically PL lamps i.e. 2 or 4 pins at the base) are about the same cost as HPS fixtures, have a good lifespan of 10,000 to 25,000 hours, with a solid CRI of 80+. The advantages of fluorescent include a low price point for wall pack installation. On the other hand fluorescent fixtures have reduced lumens in colder climates. If the lamps are allowed to warm up over time, and are in a closed housing they overcome low temperature issues. Their life span may also be reduced by high ambient temperatures. Wall lights using CFL technology are self-ballasted lamps, typically used for residential; commercial fluorescents use remote ballasts which improve efficiency and life span. The most common lamps used in outdoor wall packs are 42W PL, sometimes using two lamps in a single fixture. Used fluorescent bulbs are considered hazardous waste, requiring special handling and processing after re-lamping. 10. Induction Lighting Induction lamps are known for their long lifespan. These lamps also have advantages in applications where lamp replacement is expensive or difficult, such as in airports and tunnels. Induction light output is low temperature and these lamps can start at very low temperatures making it a good choice for cold climates. Induction lamps generate a crisp white light with a solid CRI of 80+. Induction lamps and ballasts are sensitive to high temperatures so care needs to be taken to ensure the fixture has proper heat sinking and ventilation. lighting glossary rabdesign.ca 7

8 FACTORS IN SELECTING OUTDOOR WALL LIGHTS 1. Size 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 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. lighting glossary rabdesign.ca 8

9 FACTORS IN SELECTING OUTDOOR WALL LIGHTS 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. lighting glossary rabdesign.ca 9

10 FACTORS IN SELECTING OUTDOOR WALL LIGHTS 6. Housing/ Construction Outdoor fixtures need to be durable, as they will be subjected to 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. 7. Maintenance 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 and industrial plants may need to wait for plant shutdown periods. Also cleaning lenses will improve efficacy so the fixtures need to be accessible. 8. Certification 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. lighting glossary rabdesign.ca 10

11 FACTORS IN SELECTING OUTDOOR WALL LIGHTS 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 important 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 lumen output 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 lumen output for the space. lighting glossary rabdesign.ca 11

12 SUMMARY 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. Outdoor lighting is meant to create a safe and secure environment, lighting entries and exits and also adding aesthetic value. The main factors to consider when selecting outdoor wall lights include illuminance, uniformity, light distribution and also light pollution and dark sky requirements. Traditional wall lights luminaires and light sources have certain cost and other advantages, but when compared to today s LED technology, they fall short. Despite higher costs, LED wall lights need to be considered as a solid long term solution based on their longer lifespans, energy savings, and flexibility in output and colour choices as well as colour maintenance. lighting glossary rabdesign.ca 12