The Commercial Buildings Energy Consumption Survey is probably your best bet. Take a look at the spreadsheets under "End-use equipment". There you will find a breakdown of how often each equipment type is used in different types of buildings. For example:equipment".

The Commercial [Commercial Buildings Energy Consumption Survey Survey](http://www.eia.gov/consumption/commercial/data/2012/_ is probably your best bet. Take a look at the spreadsheets under "End-use equipment".