A field study of thermal comfort with underfloor air distribution

• Thermal comfort survey of office workstations with underfloor air distribution.
• Predicted and actual thermal sensation matched closely.
• Actual thermal sensation slightly cooler than neutral.
• Preference for more air movement.

Field measurements and questionnaires based on the ASHRAE RP-921 project protocol were used to assess thermal comfort in a cold climate office environment with underfloor air distribution. All male and 90% of female participants ranked the thermal environment at their desk areas acceptable at the time of the survey. The median operative temperature was about 23 °C and ranged from 22 °C to 24 °C. The median average mean vote was −0.5, slightly cooler than neutral. Despite only 21% of participants voting warmer than neutral and only 15% expressing a preference for cooler conditions, 32% indicated that they would prefer more air movement. About 18% responded that they experienced some discomfort in body regions.