Important aspects to take into account with grow lighting

As well as its benefits to plant growth, there are consequences associated with artificial lighting.The most important are:

Extra heat is brought into the greenhouse.As a rule of thumb, ± 13µmol m-2.s-1 (± 1000 lux based on HPS Lamp) will increase the greenhouse temperature by 0.5-0.6 °C.Excessive temperature inhibits plant growth

A lighting installation can cause ‘light pollution’ if excessive light is emitted outside the greenhouse.This light emission can become an environmental and social issue. Dutch legislation prescribes moments when emission of light must be totally prevented and when emission is allowed.

Light screens reflecting 95-100% of the light back into the interior should be used in new greenhouses and in future for old greenhouses as well. An advantage of such a screen is that the reflected light is usefully employed to achieve a higher growth light level at plant height.A disadvantage of a light screen is that temperature inside the greenhouse becomes more difficult to control

Over time, the performance of a light installation can decrease, resulting in a lower irradiance level for the plants. Not only light depreciation of the lamp, but also dirt on the reflector can be the cause of this effect. It is highly recommended that irradiance be measured on a regularly basis (yearly), and that a schedule be established for re-lamping and cleaning

The performance of a light installation can decrease or damage due to ageing of its components.This not only results in a lower irradiation level, but can also become dangerous. Maintenance should therefore be carried out on a regular basis.