With the summer-like weather officially behind us, it's time for chillers to chill and other mechanical cooling systems to take a little R&R. Any off-season cooling requirements from internal heat gain or process heat can be satisfied by taking advantage of the cool outdoor air for economizer free cooling. Implementation of airside or waterside economizer systems can offer significant operational cost savings as well as equipment and maintenance cost benefits. Less run time for mechanical cooling equipment results in longer overall service life.

October is really the first month that economizer cooling systems can be initiated, at least in the Northeastern and Midwestern cities, and this year proved to be fruitful for some. Chicago, Minneapolis, and St. Louis all experienced at least 100 more airside economizer hours compared to normal. On the waterside, Boston, Detroit, and Minneapolis benefited the most.