Comfort (KS6)

Buildings are designed to meet our basic need for: — shelter: protection from the elements— security: safety— comfort: warmth and light.Many of these basic needs were originally met by a cave with a fire at the entrance to provide both security and warmth and light. Nowadays, although we might expect more sophistication in delivery, and more facilities, the fundamental needs remain the same.Once the needs for shelter and security are met, the remaining main requirement is for a 'comfortable' internal environment. Whilst this may seem a simple task to achieve, in practice there are many factors to be considered in the aim to provide comfortable conditions for the building occupants. Thus one of the primary functions of buildings and building services systems is to create and maintain a comfortable environment. Achieving the 'right' environment is the main goal of good building services design — whether a comfortable work or leisure environment for people or the correct operating conditions for machinery or equipment. Electronic and process equipment often requires far more stringent conditions than people.The main factors that influence comfort for people relate broadly to our senses i.e. touch, vision, smell, hearing. Thus the design of the building services systems must provide a good thermal, aural and visual environment - i.e. fresh air and warmth or cooling, no unwanted noise or odours and good lighting. Design criteria exist for all these factors but the choice depends on many variables including use of the space, activity level, clothing level and age of occupants, etc. Decisions on design conditions are made harder by the fact that comfort is a very subjective response with different people having different comfort levels; so the main aim is literally to 'keep most of the people happy most of the time.'In surveys of user satisfaction within buildings* comfort issues, particularly temperature and air freshness, are among those rated as the most important aspects. The same studies also show that dissatisfaction with the internal environment, particularly the thermal environment, is widespread with complaints of overheating in winter and coldness in air conditioned buildings in summer commonplace.