Book - School of Science and Technology

scale on the right hand side is provided as an aid to interpolation between the curves. Thebroken lines illustrate the following applications to practical problems:Example 1Capital cost of energy saving measure having a 60-year life as for the building £8000Estimated annual saving at present day prices £1540Ratio ˆ 8000/1540 ˆ 5:2From the chart, even if energy costs do not rise disproportionately, the measure will beviable at 7.6 years and profitable thereafter.Example 2Capital cost of energy saving equipment requiring renewal every 15 years £2000Multiplier from table 1.31Estimated annual saving at present day prices £236Ratio ˆ (2000 1:31)/236 ˆ 11:1From the chart it may be seen that:. The equipment will never be viable unless energy costs rise disproportionately to thegeneral level of inflation.. If energy costs rise disproportionately at 7% per annum, the equipment will be viable at13.5 years.. The equipment will be viable at the end of the building life (60 years) if energy costshave risen disproportionately by about 1% per annum over the whole period.To conclude this brief attempt to explain the impact of economic factors upon energyconservation measures, the authors feel bound to add that they cannot accept that costequations are the end of the story. These take no account of amenity values, thermal andvisual comfort, aesthetics, contentment, productivity and quality of life. Some at least ofthese aspects should be quantified and introduced as weighting to the results produced bysoulless mathematics. There remain, furthermore, the fundamental issues of national andinternational importance that the remaining reserves of energy be husbanded and thatCO 2 emissions be limited to minimum practical levels. Economic considerations shouldperhaps be regarded as of secondary importance.Further readingFurther reading 687BRECSU publications: Energy Consumption Guides series; Good Practice Guide series; Fuel Efficiencybooklets.Building Services Component Life Manual (from work by the Building Performance Group), published byBlackwell Science Ltd.CIBSE Application Manual No 5, Energy Audits and Surveys.CIBSE Energy Efficiency in Buildings, 1998.CIBSE Guide to Ownership, Operation and Maintenance of Building Services.Department of the Environment, Transport and the Regions (DETR) Energy Efficiency Best PracticeProgramme publications (www.energy-efficiency.gov.uk).Energy demands for air-conditioned buildings, CIBSE Energy Code 2.Energy demands for heated and ventilated buildings, CIBSE Energy Code 1.HAPM Components Life Manual (Commissioned by Housing Association Property Mutual Ltd.), publishedby E&FN Spon.Irving, S.J. The CIBSE Weather Year: Weather Data and its Application, CIBSE Symposium Proceedings, 1988.Petherbridge, P. and Oughton, D. R., `Weather and solar data', BSERT 4 (4) 1983.Standard maintenance specification for mechanical and electrical services in buildings, SMG 90, publishedby HVCA.