Reference and tools...
Free UK degree-day figures
Data for January 2012Access to free degree day data: free degree-day data are now accessible only with a password, which is changed from time to time. Current login details are circulated in our free newsletter. Please follow this link to sign up.
Also previous reports: December 2011; October 2011; September 2011; August 2011; July 2011; June 2011; May 2011; April 2011; March 2011; February 2011; January 2011; December 2010; November 2010; October 2010; September 2010
The free figures are monthly, for heating only, to a base temperature of 15.5°C, and only for 18 UK centres. For more places (including outside UK), alternative base temperatures, cooling figures, or weekly data see how to subscribe to Degree Days Direct.
Download Energy management leaflet 7 (PDF format) for basic information about degree-day data and how to use them, or view frequently-asked questions.
Thanks to Giles Branson of business cost reduction consultants Auditel for tracking down the source of benchmark data used in Display Energy Certificates: CIBSE TM46:2008 Energy Benchmarks
UK natural gas calorific values
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Natural gas is metered by volume and its energy content varies with its pressure, temperature
and calorific value. Higher supply pressure and lower temperature both increase the density of
the gas, increasing the energy delivered per volume delivered (and vice versa). The illustration shows a corrector readout, piggy-backed on a gas gas meter.
The composition of the gas also changes slightly from time to time, which means that the calorific value (energy content per unit mass) will also vary. The CV is reported on invoices. There is no in-line equipment which can be used to measure the CV between bills; however, the UK is split into 33 local delivery zones (LDZ) and daily reports of CV for each LDZ are posted here by National Grid. This information enables you to convert pressure-and-temperature-corrected volumetric readings into energy terms more accurately in between invoices if, for example, you are trying to monitor on a weekly basis.
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Going equipped
If you are doing your own energy surveys (or doing them for clients) have a look at the list of recommended equipmentU-values
12 June 2006: added on-line U-value calculator. Define your structure by entering the material and thickness for each layer, inside to out. Includes condensation risk assessment.
Reference data
Physical constants, calorific values, units of measurement and other authoritative reference data are available free in the on-line version of Kaye & Laby 16th edition. (V.V. 27 Oct 05)Conversion factors
Energy content of fuels typical conversions from metered units (eg litres of oil) to kWh. View short table. See also UK government spreadsheet with more extensive range of fuels, including estimated historical averages by industry for those fuels with variable properties.Transport CO2 emission factors: UK government guidance
General-purpose
| I noticed this rather neat units-conversion program on a someone's PC; download free from joshmadison.com (V.V. 14/10/05) |
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