The Use of the Physiological Thermal Index (PTI) as an Alternate to Effective Temperature for Civil Defense Planning.
Abstract
Ventilation planning for survival shelters had been based on the effective temperature (ET) concept established in the literature of the American Society of Heating, Refrigeration and Air Conditioning Engineering (ASHRAE). The ET concept has been repeatedly subjected to criticism by several research workers and alternatives have been proposed. One, the new effective temperature (ET*) has replaced the ET concept in the current ASHRAE literature. Another, the Physiological Thermal Index (PTI) has been developed by University of Santa Clara researchers under DCPA sponsorship. A comparison is presented here among three human thermal models that relate to these new indicies of comfort. The comparisons are in the context of suitability for predicting ventilation requirements for survival shelters. Some inadequacies are found in all three models. The principal conclusion is that the ET* index of comfort found in current ASHRAE literature predicts warm hot comfort conditions at combinations of temperature and humidity that are greater than those recommended by the PTI and ET scales. Hence, caution is advised and more study recommended before the ET scale in the DCPA literature is supplanted by the ET*. Adoption of the PTI scale appears to be a more satisfactory alternative. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1977
- Accession Number
- ADA056253
Entities
People
- James T. Macdonald
- Richard K. Pefley
Organizations
- Santa Clara University