Degree-days
Subtitle: theory and application
Series: CIBSE -- TM41: 2006; CIBSE -- TM41: 2006.
Publisher: Chartered Institution of Building Services Engineers
Published: 2006
Place of publication: London
Language: eng
ISBN-13: 9781680150193
Subjects: Degree days; Commercial buildings; Energy consumption; Degrés-jours; Immeubles commerciaux; Consommation d'énergie
Description: Degree-days are a tool that can be used in the assessment and analysis of weather related energy consumption in buildings. They have their origins in agricultural research where knowledge of variation in outdoor air temperature is important, and the concept is readily transferable to building energy. Essentially degree-days are a summation of the differences between the outdoor temperature and some reference (or base) temperature over a specified time period. A key issue in the application of degree-days is the definition of the base temperature, which, in buildings, relates to the energy balance of the building and system. This can apply to both heating and cooling systems, which leads to the dual concepts of heating and cooling degree-days. This TM replaces previous guidance given in section 18 of the 1986 edition of CIBSE Guide B [CIBSE 1986] and Fuel Efficiency Booklet 7 [Energy Efficiency Office 1993]. It provides a detailed explanation of the concepts described above, and sets out the fundamental theory upon which building related degree-days are based. It demonstrates the ways in which degree-days can be applied, and provides some of the historical backdrop to these uses. --
Notes: Includes bibliographical references.
Table of contents: title: 1.; title: An introduction to degree-days and their uses:; title: An introduction to calculating degree-days ; Degree-days for energy estimation ; Degree-days for energy management -- -- 2.; title: Calculating degree-days:; title: Mean degree-hours ; The Meteorological Office equations ; Mean daily temperature ; Hitchin's formula ; Other methods ; Errors associated with calculation methods ; Base temperature correction ; Summary -- -- 3.; title: Energy estimation techniques:; title: Heating applications ; Intermittent heating ; Accuracy and uncertainty ; Carbon dioxide emissions ; Determination of gains ; Cooling applications ; Summary -- -- 4.; title: Worked examples:; title: Heating ; All-air cooling -- -- 5.; title: Using degree-days in energy management:; title: Normalisation of energy performance indicators for weather ; Energy signatures ; Performance lines and degree-days ; Further diagnostics using performance lines ; Regression analysis: caveats and interpretations ; Summary. -- -- Appendices: -- 1.; title: Degree-day errors ; -- 2.; title: Ratios and corrections ; -- 3.; title: Base temperature conversion using Hitchin's formula ; -- 4.; title: Derivation of mean internal temperature for intermittent heating ; -- 5.; title: Areas of on-going work.