I was often surprised by the wide range of claims about the effectiveness of an energy management system (EMS) to reduce energy consumption. I have seen gains ranging from 10% to 35% of expected savings. Although this wide range can be attributed to the range of features of different systems, I have actually seen this complete range claimed even for systems with the same heating and cooling control features.
I thought it would be interesting to explore what levels are reasonably achievable to assist in the process of analyzing the requests made by EMS service providers. Since we focus on small commercial facilities, we limit the discussion to less than 15,000 square feet and analyze retailers and restaurants in particular.
EMS Saves In a Retail Environment
The use of energy varies according to many factors, of which the climate is perhaps the most important. However, to simplify matters, it is not unreasonable to assume that in a "typical" retail environment, heating and cooling are responsible for 40% of the load, lighting represents an additional 40% and 20% is heating some water. charging points and other various applications.
Suppose also that our retail store is open 12 hours a day. According to the studies, for every 1 degree setting of the cooling setpoint, one saves about 3% (again, simplification, the range varies depending on various factors). If the nightly cooling setpoint is increased from 72 to 80 degrees, overnight savings will be approximately 24% for this period, bringing the total HVAC savings to 12% of HVAC costs, or 4% of HVAC costs.
8% of the total cost of energy. (Ignore the fact that heating savings are lower and refrigeration will not be needed throughout the year). If we add the possibility of increasing the temperature by an average of 2 degrees during the day, this represents an additional saving of 1.2%.
If we assume in the worst case of lighting that all lights are lit 24 hours a day, 7 days a week, the lighting controls save up to an additional 20% of energy consumption. This brings us to maximum theoretical savings of at least 26% for HVAC and lighting controls.
EMS Savings in a Restaurant Restaurants have a lot more equipment than retail stores and spend a lot more energy because of all their cooking, refrigeration and ventilation equipment. The potential savings in dollars are therefore considerably higher. This does not mean that the percentage of savings is, however.
Again, using very wide averages, heating, and cooling accounts for about 30% of a restaurant's energy costs, while lighting accounts for about 18%. And, the restaurants can be open more hours. If we used the same type of analysis as previously for a restaurant open 16 hours a day, we obtained a maximum saving of 3.6% of energy expenditure for heating and cooling and 9% for lighting, for a total of 12.6%. Of course, with a restaurant, there are also potential savings from various other amenities, including bell leaks, refrigeration, grills, and so on.
About the Company
Brieza - Energy Management Solutions and Services
2477 Jefferson St, San Diego, Ca 92110
