Safety factor
Short definitionThe margin added on top of the calculated load, together with the assumed number of hours the compressor runs per day.
However carefully the calculation is done, conditions on site change: the door opens more often, the product arrives warmer. A margin is added to the total load to cover this uncertainty.
The second allowance is run time. A compressor is not selected to run 24 hours a day. Time is left for defrost and for off-cycles. The daily load is divided by the accepted run hours to find the required capacity.