This text is a reference for the day-to-day work of the engineer or technician engaged on the design of HVAC systems, domestic hot and cold water services, gas supply and steam services. There is material in the air conditioning section providing data for recently introduced systems. There is information on expansion of gases and on replacement refrigerants for CFCs and HCFCs. The reader is presented with brief summaries of the various types of system which can be considered, together with the formulae, physical constants and typical design parameters needed for actual design and estimating. There is also a list of British, European and international standards.