- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 08 Jul 2014
Predicted mean vote
The predicted mean vote (PMV) was developed by Povl Ole Fanger at Kansas State University and the Technical University of Denmark as an empirical fit to the human sensation of thermal comfort. It was later adopted as an ISO standard. It predicts the average vote of a large group of people on the a seven-point thermal sensation scale where:
- +3 = hot
- +2 = warm
- +1 = slightly warm
- 0 = neutral
- -1 = slightly cool
- -2 = cool
- -3 = cold
The properties measured and the maths required to create the empirical fit are very complicated, based on the deviation between heat loss and metabolic rate, and the equations generated only apply under constant conditions and at constant metabolic rates. However, as the conditions within the built environment will generally be within a small range, and the clothing, metabolic rates and so on of occupants can be predicted, standards have been produced indicating thermal conditions that will give a satisfactory predicted mean vote. For example, the ASHRAE Standard 55 Comfort Zone represents a predicted mean vote of of between -0.5 and +0.5 for buildings where the occupants have metabolic rates of between 1.0 met and 1.3 met and clothing provides between 0.5 clo and 1.0 clo of thermal insulation.
 Find out more
 Related articles on Designing Buildings Wiki
Featured articles and news
Do you understand the different types of stone and which ones you should use where?
Why a wellbeing strategy is vital for property managers.
An ECA briefing for members about the commercial implications of leaving the EU.
A crucial moment on any project - and fraught with danger.
The performance gap from a Northern Ireland perspective.
Book review: Buildings of protestant nonconformity.
Design and testing for health and wellbeing - free download from BRE.
Retention in construction contracts.
Campaign for the reform of cash retentions.
The key points for the construction industry and BSRIA's response.
How to make roads safer: the debate continues.