Selecting the capacity of a central air conditioning (AC) system is based on a long list of structural factors within a home, but is normally chosen without considering effects on stakeholders outside of the home. Energy use by residential air conditioners is relevant to consumers as an expense, but also to utilities as a contributor to peak demand and to society by the resultant carbon dioxide and other emissions. In this article, we investigate how size and operational patterns of central residential air conditioners interact with stakeholder benefits and costs. The case study analyzes energy use for systems sized from 3.0-5.5 tons in single family homes in Phoenix, Arizona and quantifies the costs and benefits to homeowners, electric utilities, and society. For homeowners, larger units are preferred due to lower energy consumption, leading to lower net costs, and the ability to cool the house quickly. However, under the same conditions, a smaller AC system can provide double the potential profit to the utility from reduced generation and peak load costs. As a result of lower energy consumption, larger units have lower environmental externality costs from carbon and criteria pollutant emissions. However, a social perspective that considers homeowner, utility and externality costs together results in an overall preference for smaller units with setback schedules, driven by the value of peak demand reduction.
Sustainable Engineering (MS)
Department, Program, or Center
Industrial and Systems Engineering (KGCOE)
Amoroso, Briana Elizabeth, "Comparing Economic, Environmental, and Social Effects of Central Air Conditioner Size and Thermostat Schedule Interactions" (2017). Thesis. Rochester Institute of Technology. Accessed from
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