When a homeowner purchases a new highly energy-efficient air conditioner, that means that running the A/C will become less expensive–because it won’t consume as much electricity when it runs.
But if it costs less to operate, then will the owner use their A/C much more often than before? If so, then the increased use of the A/C could offset some of the energy efficiency benefits of the new air conditioner.
This phenomenon, which also comes up in the context of how a driver’s habits may change when they purchase a fuel-efficient vehicle, is known as the “Rebound Effect.”
The question is: how big is the “Rebound Effect”?
The answer, according to a white paper published today by the non-profit organization American Council for an Energy Efficient Economy, is “not very large.” The direct rebound effect appears to amount to 10% or less in most cases–implying that a homeowner who buys an efficient air-conditioner might end up running it slightly more often than their old system.
Even given this slight uptick in appliance usage, the paper asserts that the net outcome of energy-efficiency programs and policies is still a clear and meaningful reduction in total energy use.
Read more about the rebound effect in ACEEE’s white paper, The Rebound Effect: Large or Small?.