Develop the thermal comfort survey after determining space programming, designing the mechanical system, and confirming compliance with IEQc7.1. It is best to customize the occupant survey for the building’s planned HVAC systems. Questions may be structured differently depending on whether you are assessing the performance of an evaporative cooling system, an in-floor radiant heating system, or a natural ventilation system.
Develop a survey that addresses measurement of these variables (see below for more details), or contract with a third-party occupant survey service. You can find a sample thermal comfort survey in Appendix E of ASHRAE-55.
Provide occupant controls for each individual space and avoid trying to normalize conditions in large areas or zones of a building. Separate controls will make it easier to achieve the credit in all spaces and improve occupant comfort while reducing unneeded energy use. For example, if there are ten adjacent offices, provide controls for each office separately. This strategy can also help you earn IEQc6.2: Controllability of Systems—Thermal Comfort.
Natural ventilation designs are more significantly affected by climate and weather than mechanical systems. Although the methodology and inputs for documenting compliance are the same as for mechanical systems, in certain regions project teams using passive systems may have difficulty meeting ASHRAE-55 due to program constraints or seasonal temperatures that are outside of the prescribed range of 50°F–92°F.
Don’t assume that projects in Southwestern or other dry climates will automatically meet the humidity requirements of ASHRAE-55. These climates may have a significant number of days in which operating conditions will exceed the ASHRAE-55 requirements for humidity. Refer to the National Climatic Data Center for regional weather data (see Resources).
Review how thermal controls and operable windows affect credit requirements. Projects in very temperate climates may meet the credit requirements through the use of operable windows exclusively, as long as mean monthly outdoor temperatures are between 50°F–92°F. See ASHRAE-55 section 5.3 for details.
