Although the fundamentals of the subject have not altered since the publication of the last edition there have been significant changes in the development and application of air conditioning. Among these are concerns about indoor air quality, revision of outside design data and the expression of cooling loads arising from solar radiation through glass by the CIBSE. The phasing-out of refrigerants that have been in use for many years (because of their greenhouse effect and the risks of ozone depletion) and the introduction of replacement refrigerants are far-reaching in their consequences and have been taken into account. The tables on the thermodynamic properties of refrigerant 22 have been deleted and new tables for refrigerants 134a and ammonia substituted. There have also been new developments in refrigeration compressors and other plant. Advances in automatic controls, culminating in the use of the Internet to permit integration of the control and operation of all building services worldwide, are very important. Revisions in expressing filtration efficiency, with an emphasis on particle s'ize, have meant radical changes in the expression of the standards used in the UK, Europe and the USA. The above developments have led to changes in the content, notably in chapters 4 (on comfort), 5 (on outside design conditions), 7 (on heat gains), 9 (for the refrigerants used), 12 (automatic controls) and 17 (on filtration standards).
Two examples on heat gains in the southern hemisphere have been included.
As with former editions, the good practice advocated by the Chartered Institution of Building Services Engineers has been followed, together with the recommendations of the American Society of Heating, Refrigerating and Air Conditioning Engineers, where appropriate. It is believed that practising engineers as well as students will find this book of value.