Lighting technology has come a long way since the times of the incandescent lamp and with several different types of lamps now available choosing the right lamp to suit your indoor gardening needs can, at times be confusing. There are other accessories to consider too like starters, timers, wiring etc. which can further confound the uninitiated. But while considering all the paraphernalia, growers sometimes tend to neglect one extremely important aspect of the lighting systems – reflectors.

Importance of Reflectors
To get the best from their lighting system growers would do well to understand how reflectors work and how reflector design has evolved over the years with advances in lighting technology. Reflectors perform the very important function of gathering the light emitted by the lamp and then directing it as required. Therefore, even though you may use the best lamps in the market, if you don’t use the right reflector most of the light produced by the lamp might be wasted. However, “tall crop" growers need not be concerned as their crops can soak up all the light they need from just bare lamps hanging down among the plants. “Short crop" (plants under one meter tall) growers, need to carefully consider available reflector designs to choose the one best suited to their needs.

Reflectors come in different designs and not all designs have comparable efficiencies. Some reflectors are many times as efficient as others thanks to the technical improvements in reflector design and manufacturing. One of the problems in the past was rooted in the misunderstanding of how H.I.D. (High Intensity Discharge) lamps produce light. HID lamps give their strongest light from the sides of the lamps, quite unlike the typical incandescent bulb. Vertical mount reflectors, which were the first reflectors developed for HID lamps proved highly inefficient with only about 9% of the light reflected to the plants. The rest of the light output was completely wasted in illuminating the grow room walls.

Developments in Reflector Design
Lighting efficiency increased dramatically with the introduction of the horizontal reflector. The sideways orientation of the lamp also increased the direct light to the crop as also the horizontal reflector which bounced more light to the crop. This arrangement seemed fine for some time until the lamps started burning out after only a few months.
Also there was always the possibility of electrical shorts in the socket wiring associated with this design. The reflector design then underwent major modifications with more open designs, incorporating vents, ducting even small exhaust fans. With the basic design features incorporated the attention turned toward the finding the material that would reflect light most efficiently. The specifications called for a surface that would reflect the light and also distribute it evenly onto the crop without localized heating and shadowing. Several years of research led to the development of a flat white surface that – coated with Titanium Oxide –fitted the bill to a T. It reflected 20% more light than the best glossy white finish. It also did not produce the uneven glare that the most reflective of glossy surfaces produce. With a unique method of applying Titanium coating the surface reflectivity touched 95%, i.e. the surface was able to reflect 95% of the light incident on it to the crops. This reflected light in addition to the direct light from the lamp, boosted the overall lighting efficiency in the garden to near perfect levels.

Benefits of Improved Design
Growers were quick to realize that these new reflectors offered an important benefit – they were no longer constrained to locate their growing systems in inaccessible locations. With the old style reflectors that allowed most of the light to fall on the walls growers tried to redirect some of this wasted light by covering the walls with Mylar or other reflective materials. But this resulted in gardens being moved into corners to take advantage of the reflective wall coverings creating problems with poor air movement, heat build up and inaccessible plants. All that changed with the new reflectors- light was now directed onto the garden, no light wastage on the walls meant no need for reflective walls and no need to locate the grow area in cramped spaces.

Accessible locations for the gardens improved air movement eliminated the problem of heat build-ups and promoted more growth friendly conditions in the garden. A free-standing garden with easy, unhindered could now allow easy access for inspection and carrying out other chores that help plant growth. It also discourages unwanted intruders like pests and bugs.