Impact of systems generating local air movement on thermal environment and occupants

The positive effect of air movement on the occupants’ thermal comfort was also acknowledged in the recent updates of the standards. ANSI/ASHRAE 55-2004 and ISO 7730: 2005 specify the necessary air velocity increment to offset temperature increases above 26◦C. So far this temperature has been recognized as the upper limit for the occupants’ thermal comfort. Devices and systems used for the convective cooling described above may create a very non-uniform environment. Thus application of the recommendations given in the standards may be limited.