Wall lights 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.
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.
2. 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.
3. 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 higher quality light.
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.
5. 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.