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Measuring thermal comfort

A simple way of estimating the level of thermal comfort in your workplace is to ask the workers or their workplace representatives (such as Unions or employee associations) if the percentage of workers dissatisfied with the thermal environment is above a certain level, you will need to take action. See the five steps to risk assessment for more details for more details.

If you wish to measure thermal comfort in a more scientific manner, please refer to the British Standards listed in Calculating thermal comfort.

Thermal comfort checklist

Use the table below to help you identify whether there may be a risk of thermal discomfort to your employees. Please note that this is a basic checklist and does not replace an adequate thermal comfort risk assessment. Read the descriptions for each thermal comfort factor, and tick the appropriate box. If you tick two or more ‘YES’ boxes there may be a risk of thermal discomfort and you may need to carry out a more detailed risk assessment.

Thermal comfort checklist
Factor Description YES
Air temperature Does the air feel warm or hot?  
Does the temperature in the workplace fluctuate during a normal working day?  
Does the temperature in the workplace change a lot during hot or cold seasonal variations?  
Radiant temperature Is there a heat source in the environment?  
Humidity Is there any equipment that produces steam?  
Is the workplace affected by external weather conditions?  
Are your employees wearing PPE that is vapour impermeable?  
Do your employees complain that the air is too dry?  
Do your employees complain that the air is humid?  
Air movement Is cold or warm air blowing directly into the workspace?  
Are employees complaining of draught?  
Metabolic rate Is work rate moderate to intensive in warm or hot conditions?  
Are employees sedentary in cool or cold environments?  
PPE Is PPE being worn that protects against harmful toxins, chemicals, asbestos, flames, extreme heat, etc?  
Can employees make individual alterations to their clothing in response to the thermal environment?  
Is respiratory protection being worn?  
What your employees think Do your employees think that there is a thermal comfort problem?  

Calculating thermal comfort

In most instances, the guidance given on this website will be sufficient to enable you to improve thermal comfort in your workplace. However, you may wish to measure the factors contributing to thermal comfort more accurately. The predicted mean vote (PMV) and percentage people dissatisfied (PPD) index and use of BS EN ISO 7730 and BS EN ISO 10551 British standards are recommended.

The PMV/PPD index predicts the thermal comfort of people working in a given environment. It uses the six basic factors, and has become the most widely used index in recent years. It has been adopted as a British and European and International standard.

Next: Controlling thermal comfort

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2012-11-06