Illuminanceon for multiple point source calculations. That seems like a lot of lights but if you consider all the light possibilities for a kitchen: dimmable recessed lights, some under cabinet lights, the light on the stove top vent hood and a few track or hanging lights right above an island or prep counter, you could reach that ten bulb level. Below the table you'll find an example home lighting calculation for a kitchen. A standard 40-watt (40W) bulb is equal to 400+ lumens. Luminaires located at or near the center of an area should be IES type 3, 4 or 5 depending on the coverage, intensity and uniformity required. The maintenance or light loss factor is an allowance for depreciation of lamp output with age and floodlight efficiency due to the collection of dirt on lamp, reflector, and cover glass. When an additional floodlight is added to a single pole, horizontal aiming also must be considered. Illuminance directly below the luminaire on a horizontal surface. Thus narrow-beam floodlights are preferable where they will provide the necessary degree of uniformity of illumination and the proper footcandle level. so, Mounting height = 1/2 distance to be lighted = 1/2 (40ft.) An estimated CBU can be determined by experience, or by making calculations for several potential aiming points and using the average figure thus obtained. It is equal to the number of degrees between the 10% of maximum candlepower (near the center of the beam) locations. If less than 60% of the beam lumens are utilized, a more economical lighting plan should be possible by using different locations or narrower beam floodlights. Beam lumens are defined as the quantity of light that is contained within the beam limits described as. If you are working in metres, simply exchange the footcandle numbers for the appropriate lux numbers from the table and calculate your room area in square metres. The total factor may vary from .65 to .85 depending on the type of lamp and luminaire used, and may include losses due to lamp orientation or “tilt.”. Ratio lateral distance mounting height = 75/30= 2.5(mounting heights). If you are using a very small screen or smart phone, rotate your device to landscape view to read the table below. By multiplying the length and width of our kitchen together we get 10 feet X 12 feet = 120 square feet. When you purchase light bulbs there will generally be two numbers of interest on the packaging. It refers to a light bulb's brightness, intensity of light and visible light emitted. If you're working in feet, calculate the area in square feet and use the footcandle value from the light table. When designing areas with cutoff or dropped lens type the quantity of floodlights (N)is determined by the following basic formula: Rearrange the basic formula given in step-5 above to get the level of illumination (fc) as follows: If the area to be lighted is 40 feet across, the recommended aiming point is 27 feet. For our example let's use 20 Watt CFLs rated at 1200 lumens. Affordable, efficient, and can be designed easily. For a more personalized home lighting design, do a few quick calculations in your current home to determine the light level in a given room. This page will teach you how to calculate lighting levels. So for our lowest light requirement of 2400 lumens, the calculation would be: 2400 lumens / 1200 lumens per bulb = 2 bulbs. Environmental lighting such as lighting of parks, gardens, sea shores, monuments and historical sites. Typical distance from luminaire to the edge of an area should not exceed one half of the spacing between adjacent luminaires.see below image for recommended spacing guide: Additionally, to minimize glare, the recommended aiming point distance should never exceed twice the mounting height. For our basic general kitchen lighting, we know from the table above that we'll need 20-50 footcandles. , the same procedures for calculation will be followed in area lighting (floodlighting) design.