Six Basic Factors Of Thermal Comfort

Our last post covered why thermal comfort is important in the workplace, this post goes into more detail about the six basic factors of thermal comfort.

Firstly lets start with some interesting facts.

Fact: Thermal discomfort caused by air conditioning is the UK Building Research Establishment’s biggest climate control complaint.
Fact: 74% of British workers argue with colleagues over air conditioning.
Fact: 72% of British workers feel their office never gets the temperature right, making them feel uncomfortable, cold and unproductive.

The HSE states thermal comfort should be measured in ‘six basic factors’ which can either be independent of each other, or combine to create thermal discomfort. They are broken down into environmental factors and personal factors.

Environmental factors:  Simply put, environmental factors are things that affect the indoor environment you are in. They include the following:

Air temperature – The temperature of the air surrounding your body.

Radiant temperature – Thermal radiation is the heat that radiates from a warm object; radiators, electric fires, furnaces, ovens, cookers, dryers, machinery, the sun, etc.

Air velocity -One of the most important factors in relation to thermal comfort because people are sensitive to air movement patterns. Air velocity is the speed at which air moves across a person e.g. cooler air moving at a faster rate may cool a worker down, while still, heated air may make people feel stuffy. Equally important is the fact that air causes draughts – if the air temperature is less than skin temperature, it will increase heat loss through the skin, even when the system is in heat mode.

Humidity – Relative humidity is the ratio between the actual amount of water vapour in the air and the maximum amount of water vapour that the air can hold at that air temperature. The more relative humidity in the air (i.e. the higher the ratio), the harder it is to sweat as humidity prevents the evaporation of sweat from the skin.

Personal factors: These are factors which are individual to you:

Clothing insulation –Thermal comfort is directly affected by the clothes you wear. Clothing interferes with our ability to lose heat to the environment. Wearing too much clothing or PPE will make you too hot, wearing clothing with inadequate insulation in colder temperatures will make you too cold. Therefore clothing can both cause and control thermal comfort.

Work rate/metabolic heat – The more physical work you do, the more heat you produce – those in physical jobs may be more likely to experience heat stress than those who have sedentary, office based roles. In addition, factors such as your weight, size, age, fitness level and sex can all have an impact on how hot or cold you personally feel.

Adapting to avoid thermal discomfort

Where possible, employees should be allowed to adapt their situation to the thermal environment:

However, this may not always be possible – invariably people will work in an environment which is a product of their job e.g. the receptionist will work in an environment where the door constantly opens and closes leaving them exposed to the outside elements. The GP will work in a reasonably small room, mostly static at their desk, with room temperatures higher than you would expect in an office environment (they also have to deal with airborne viruses and bacteria). Office layout will also affect people’s abilities to move to hotter or colder areas of the building, or move away from draughts.

So what can you do about it? Contact Airius and a member of the team will be happy to discuss your thermal comfort with you in more detail.

Airius are air circulation experts specialising in destratification. Having over 10 years experience and an impressive client base helping SME’s to Blue Chip companies such as; John Lewis, Jaguar, Boots, Morrisons and Marks and Spencers, make real reductions in their energy usage and carbon emissions.