lightCALC advanced – Step 4 – Specify
This is the
point at which you tell the program what you wish to achieve. You will see three basic options from which
to choose. Once you select an option,
the program will calculate how many luminaires it will take to provide the
target values you assign, or what values you get based on the luminaire counts
you pre-set.
In the boxes
under the “Desired” heading, you assign values to what is most important to
you. You have a choice of setting a
target for how many footcandles you wish to achieve (Illuminance) and have the
software confirm how many luminaires it will take to provide it. The software will then provide the exact
footcandle level and the energy consumed by the lighting in terms of watts per
square foot.
If preferred,
the software can be told how many fixtures may be used. If this approach is taken, the program will
use the pre-specified counts and confirm how much light will be provided and
how much energy is consumed. If the
number of luminaires specified cannot be arrayed evenly, the program will
adjust the array to fit evenly, then provide results based on the optimized
array.
The third
option is to pre-select a limitation based on watts-per-square-foot
restrictions. Once selected, this
option guides the software to calculate how many luminaires are allowed and how
much light is generated without exceeding the watts-per-square-foot limitation.
In order to set the product wattage properly, it is necessary to make an adjustment to the lamp wattage shown under the Advanced-Luminaire tab. Simply take the total input wattage for the product being used and divide it by the number of lamps shown. Insert this value into the wattage box. This will result in LPD information (Watts per square foot) being properly set.
Notice that
this section allows you to pre-set the targets as minimum, maximum or “nearest”
to suit your needs. This feature allows
you to make certain that the calculations are run to provide the information
you need most. For example, if you know
you cannot exceed 0.8 watts per square foot, check the circle for “Maximum
Allowable” and enter .80 for the LPD factor.
The software will calculate based on this restriction and tell you how
many fixtures are allowed, and how much illumination will be provided.
Notice that
the graphic continues to update. It now
shows fixtures in-place with ceiling spacings designated.