Dear Han, I wonder which British Thermal Unit they mean.
The British Thermal unit (like the calorie, Calorie, kilocalorie, kiloCalorie etc.) is temperature dependent so it has no definite value. Of course, since the British Thermal Unit is not supported by any international treaties (like the TREATY OF THE METRE) a manufacturer could, if they wished, simply make up their own value for the British Thermal Unit. On the other hand, the joule is fully supported by the international TREATY OF THE METRE and so if the box specifies the heat energy removing abilities of the air conditioner in joules, then we all can know what that means. Here are a few of the British Thermal Units that I think are currently in use but I don't think that this collection is exhaustive there are probably many others. British thermal unit (0 °C), British thermal unit (16 °C), British thermal unit (20 °C), British thermal unit (32 °F), British thermal unit (4 °C), British thermal unit (60 °F), British thermal unit (68 °F), British thermal unit (international), British thermal unit (ISO), British thermal unit (IT), British thermal unit (mean), British thermal unit (thermal), British thermal unit (thermochemical). Cheers, Pat Naughtin PO Box 305 Belmont 3216 Geelong, Australia 61 3 5241 2008 Pat Naughtin is manager of http://www.metricationmatters.com an internet website that focuses on the many issues, methods and processes that individuals, groups, companies, and nations use when upgrading to the metric system. Contact Pat Naughtin at [EMAIL PROTECTED] On 2007 05 12 5:19 PM, "H. Maenen" <[EMAIL PROTECTED]> wrote: > I only know that the BTU/h was never used here, in mainland Europe, before. I > regard its emergence in metric countries as scandalous, soundly unneccesary > and retrograde. I think that it will bleed away at some point in the future > like the SAE-horsepower did in its day, the non-metric computer paper sizes > did recently when we reverted to A4. The BTU should never have reared its ugly > head here in the first place. We used the kcal/h where the British and the > Americans used the BTU/h. We never learned anything about the BTU at school > either. It is an invader in mainland Europe as a number of air conditioning > manufacturers are 'marketing' its use in metric countries. It is the same like > US cosmetics manufacturers like Donna Karan and Estee Lauder pushing the once > liquide (US fl.oz) on French speaking countries. And if the EU-directive was > not up for cancelling, the BTU and the once liquide would have disappeared > from metric EU nations once and for all in 2010. The directive went further > than simply bannning ifp for trade, it wanted to ban ifp once and for all in > the EU, and Britain could ask for opt outs of course. If ever I want to buy an > air conditioner I will buy it from the German manufacturer Bosch or any other > manufacturer which rates them in kilowatt first and uses the BTU/h as a > supplemental unit. Bosch has to as it sells its air conditioners to the USA as > well. > When high accuracy is not needed, converting from BTU/h to kW is very simple: > the kilojoule and the BTU are almost equal, so dividing the BTU/h by 3600 > gives kilowatt. > We do have soft converted industry standards indeed, for instance for > plumbing, but certainly the majority of our industrial measurements are now > hard metric.
