Now that we are well into the winter of 2019, designers and managers of commercial buildings in cold climates may be concerned about the efficiency of their HVAC systems. This is a good year to start being especially vigilant. Scientists in the Intergovernmental Panel on Climate Change reported that to avoid the most devastating impacts of climate change, we only have a 12-year window to decrease carbon emissions by 45 percent. Whatever beliefs each of us have, we should not be wasteful of energy.
If you are overly optimistic and know the First Law of Thermodynamics, you might be asking how it is even possible to waste energy. This law tells us that energy is always conserved, and that the total amount never changes. If this is true, then why do we need to worry about wasting it? Why can’t we simply re-use energy over and over again?