Lighting Terms

LED - light emitting diode.

Photon - a packet of energy that emits light

Heatsink - traditionally made of aluminum and designed to draw heat away from a device (LEDS in this case). The more surface area the more heat that can be absorbed

LED driver - The device that converts AC power from your wall into DC power in order to provide the proper electrical characteristics to power the LEDs connected to it. It is important to use the correct driver based on your LED power requirements.

Dimmer - a device that changes the power output of a driver I order to raise or lower the amount of power to the LEDs.

Conformal Coating - a silicone style transparent coating applied to LEDs and electrical connections to maintain water resistance and provide safe operation in a wet/damp environment.

PAR - photosynthetically active radiation -refers to the portion of the energy emitted in the 400 - 700 nM range of the visible spectrum. It is important to note that PAR doesn’t include energy emitted in the UV portion < 400 nM nor IR > 700 nM.

PPF - Photosynthetic Photon Flux refers to the total amount of energy in µmol/s emitted from a luminaire.

Luminaire - an electrical device designed specifically for light output.

PPFD - Photosynthetic Photon Flux Density - refers to the amount of energy falling on a given area. This can be calculated by dividing the PPF by the area in square meters assuming even light output.

Watt - The amount of energy consumed by a electrical device.

Efficiency - As it relates to Lighting is a measurement of the amount of energy emitted as light as compared to overall wattage consumed at the wall. Higher efficient LEDs emit more light energy and less heat than standard HID lights such as HPS and metal halide style lights.

PPE - Photosynthetic Photon Efficiency- the amount of photosynthetic energy emitted per watt of energy consumed. Characterized as µmol/watt or µmol/joule (1 watt = 1 joule/second). Calculated as PPF/wattage.

Color temperature - measured in kelvins it relates to the relative amounts of the different colors emitted by an LED. Higher color temperatures have higher percentages of blue light whereas lower color temperatures contain higher percent of red light output.

PAR map - A diagram showing PPFD measurements across a given area designed to show the evenness of light output at a given height over a specific size coverage area.

SPD - Spectral distribution (usually shown graphically using a curve) showing the relative percentage output of all the energy emitted by each color wavelength of light.