Top of Page 9. How do I measure the true energy savings from eCOOLogy if I experience a change in other equipment usage (lights, business hours, more computers, less computers)?
There are many sophisticated approaches to monitoring energy use. The simplest method to determine actual reduction in utility usage starts with estimating heat flow through a roof. The roof of a typical tilt-up building with R19 insulation will introduce approximately 110 BTU’s per square foot into the envelope of a building over the course of an 85 degree day (this may need to adjusted depending on the makeup and insulation of your specific building). When that same roof is sprinkled, it will produce only 20 BTU’s per square foot. Once the total number of BTU’s removed is determined, convert that figure to tonnage by dividing the total BTU’s by 12,000, and multiply the tonnage by 1.3 to determine the KWh saved. Finally, multiply the total KWh by your cost per KWh, and you can estimate the total reduction in electrical costs. To estimate annual savings, determine how many 70 degree (or greater) days you have in your area, and multiply this daily savings by that figure.
