This report provides the number of hours that meet or exceed the ASHRAE design cooling dry bulb and wet bulb temperatures. Note that the data represents year to date values from January through the data month (September in this case). In previous issues, only monthly values were given.
The cooling design hours in the table and Figure 0109AC show that the major Southern and Western cities experienced fewer cooling design hours than normal. In fact, the 0.4% cooling design condition was never reached in Atlanta, Los Angeles, or Memphis. On the other hand, the dry bulb cooling design hours were exceeded in most of the major cities in the Northern and Central regions. Minneapolis experienced 182-hrs above 91?. That's 5.2 times the 0.4% design of 35-hrs. Just for fun, the average cooling design hours for the 22 cities listed were 36, 88, and 185 compared to the 35-, 88-, and 175-design hrs for the three design conditions - pretty close to an average year, countrywide.