This report presents the results of a study on the efficiency of residential duct cleaning. The study was performed In 33 houses and describes the results of measuring duct flows, fan amperage, dust, and micro-organisms before and after duct cleaning. The study concludes that there were no significant improvements in duct flows, fan amperage, duct airborne dust, house airborne dust, or supply duct dust levels. Only dust concentrations in the return ducts and the concentrations in airborne micro-organisms have significantly improved after the duct cleaning.

The HVAC system for the new Standard Federal Bank headquarters in Troy, Michigan, the United States, was designed for energy efficiency, low operating costs and a high quality indoor environment. Ice thermal storage and heat reclaim from the building's data centre, in combination with a well insulated building envelope, have resulted in calculated savings of USD 62,000 per year with a payback period of 3.3 years. The design of this building's HVAC system, completed in 1989, exceeds all codesand standards for energy efficiency in the United States.

A new theatre at Bedales school, designed by Hampshire County Architects, includes on Its green agenda a cooling system made from underground concrete pipes, through which cold air is driven.