SPMV*
In an outdoor environment, the “Standard Predicted Mean Vote Modified” (SPMV*) metric is used as it can effectively account for the physics associated with elevated solar exposure and humidity ranges present outdoors. SPMV* is a modified version of the ASHRAE PMV metric which better accounts for the larger range of outdoor conditions.
Thermal comfort is a useful concept and SPMV* provides a method to communicate this concept. Still, it should be noted that the SPMV* index is based on surveys and perceptions of individuals. It is based on 80% of respondents agreeing on the condition they are feeling. It is, in no way, a definitive measure of an individual’s thermal comfort. Also, the variety of conditions and activities that impact the perception of comfort are large and varied.
Any thermal comfort analysis should therefore be viewed as a guide and not as a quantitative assessment.
SPMV (Temperate Climates) Color Legend
The color scale indicates three types of zone:
Too Cold/Too Warm – a person will stay at this location for some time but will seek better conditions.
Comfortable – this location is similar to indoors. No thermal stress.
What is it measuring?
This is a SPMV* for temperate climates. The color scale shows what the average thermal comfort conditions are at a location for a given season (range of months), time of day period (range of hours), clothing and activity level.
What options can I specify?
The Season, Time of Day, Clothing Type and Activity Type is defined by the user (or predefined for them).
SPMV HOT (Hot and Tropical Climates) Color Legend
The color scale indicates four types of zone:
Unacceptable: Too hot. A person will seek cooler conditions.
Comfortable: this location is similar to indoors. No thermal stress.
Acceptable: A person will generally accept this location as comfortable since they are outdoors. Some thermal stress.
Tolerable: A person will stay at this location for some time but will seek better conditions.
What is it measuring?
This is a SPMV* for hot and tropical climates. The color scale shows what the average thermal comfort conditions are at a location for a given season (range of months), time of day period (range of hours), clothing and activity level.
What options can I specify?
The Season, Time of Day, Clothing Type and Activity Type is defined by the user (or predefined for them).
SPMV % Inbounds Color Legend
What is it measuring?
The color scale indicates the percentage of hours within a specified time frame that are within the comfortable range.
What options can I specify?
The Season, Time of Day, Clothing Type and Activity Type are defined by the user (or predefined for them).