Optimizing Energy by Minimizing Cooling
Chris Dittmer 27000033P6 firstname.lastname@example.org | | Tags:  energy maximo optimization
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Maintaining the proper temperature in a building, facility, or data center is often the single largest driver of energy consumption and carbon footprint - in the middle of this summer heat wave, the sounds of air conditioning units hard at work resonate throughout business districts and neighborhoods everywhere I go. The thing that I always wonder about when I see those air conditioners running is "how much of that energy is adding zero value to the world?"... How much is going toward cooling spaces that no one is actually in? How much is cooling equipment that doesn't need to be cooled (or cooled so much)? How much is being sent right out a cracked open door because someone is too cold? How many of the air handling units inside have worn-out filters or have leaky duct work that is spilling cold air in unintended places?
Managing air is a tricky business. Unlike power, which can be piped exactly where it is needed, air has to be pushed to the place where it is needed. And lots of things can impede it - furniture, closed vents, leakage, etc. And if multiple air conditioners are cooling the same area, then it is very hard to predict what the temperature will be in different parts of the room. And for most air conditioned space, no one is monitoring that air at a granular level. In my home, there is a single temperature reading that drives the air conditioner at the thermostat location... it doesn't realize that my child in the top bunk far away from the thermostat is actually too warm or that my basement is too cold.
However, with the increasing prevalence of instrumentation of equipment and small, inexpensive, temperature sensors, this situation is starting to change. It is now possible to instrument rooms to determine the temperature all over the heated or cooled space. This can bring to light problems related to either overcooling or undercooling. When this information is superimposed on a map of the physical space, then the areas of inefficiency (too much cooling in one area) or risk (overheating equipment) become evident. Take a look at the following map:
In the map above (courtesy of Maximo for Energy Optimization), you can easily see where the problems lie - the crosshairs are locked in on the part of the room (colored red) that is not adequately cooled. On the other hand, we see parts of the room that are bright blue... these areas are too cold, and we are probably wasting energy, unless we had a particularly important piece of equipment that actually required an extra cold environment. Armed with this information, one can go about making the changes to eliminate these hot or cold spots. Perhaps that means sending an engineer out to reroute airflow, or simply partially shutting some vents. It could mean that we find some equipment that is turned on and producing heat that could be turned off. Maybe someone will open the maintenance logs to find out that we're not keeping up with demand because the proper maintenance wasn't done. We've even seen situations where the air coming out of an air conditioner unit was warmer than the air going into it! With modern instrumentation and software tools like these, there is simply no reason to continue to waste energy and natural resources heating or cooling air that isn't necessary to run our enterprises and our lives.