Heat Stress
- Evaluation of heat stress
- Evaluation of clothing
- Software – “HOT”
I wanted to learn a new programming language “Visual Basic 3”, so I shut myself away Easter 1996 and went from zero to an acceptable program. The source code in Basic for estimating thermal comfort was adopted from an appendix (ISO 7730 1984 Moderate Thermal Environments – Determination of the PMV and PPD indices and specification of the conditions for thermal comfort) in the first edition of Professor Ken Parsons’ excellent book “Human Thermal Environments”, but the important part to make it useful was the human interface. At that time no-one had a simple program to perform the complex calculations and my aim was to develop one that only required a mouse and could be used without instruction or a manual. Ken was very kind and gave me a copy on the second edition of his book “Human Thermal Environments”.
- An article on the program was published in the Australian Institute of Occupational Hygienist’s Newsletter in July 1996. PDF
- “Hot” – an intuitive program to evaluate thermal comfort (based on ISO). Currently being rewritten in VB6. Now on the back burner.
Unlike the “engineering” WBGT index, which only uses air temperature, a natural wet bulb and a globe thermometer, the calculation of thermal comfort also requires the use of airspeed, humidity, metabolic rate and the insulating effect of clothing. This allows much better “what if?” modelling of parameters like air speed to determine the best control strategy. Since then a lot of of has been done elsewhere to produce a physiologically based PHS (Predicted Heat Strain) Index for Heat Stress.