Conversion Factors and Methods

Conversion factors could be seen as universal constants. Some of them are exact, like 1 inch equals 25.4 mm. Most of them don't have an exact value but rather expressed as a decimal fraction with 4-8 sig figs which is enough for most engineering applications without reducing desired precision.In the lab we had to find several conversion factors. It may be OK and definitely convenient to google it, but for the lab Memo and for professional reports a google search is not a credible reference. I think the best source of reference materials such as conversion factors is a relevant industry's handbook. For HVACR it would be ASHRAE Handbook - Fundamentals. An electronic edition of it is available through Drexel libraries, but for this large class' convenience I also supply a link to the Chapter 38 image file on my Google Drive (page 1 and page 2). I hope the ASHRAE people won't be considering it as a serious breach of copyright. It can be cited as ASHRAE (2009), 2009 ASHRAE Handbook - Fundamentals (I-P Edition), Chapter 38 Units and Conversions, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. Another great reference would be ASTM/IEEESI-10-1997 Standard.The unit-factor method is a commonly used technique to convert a value from one system of units into another, or from one unit into another within the same system. Explore it more on KhanAcademy videos. Wikipedia article on it also is a good one on the unit-factor method (and of course we never refer to Wikipedia in memos and reports). Unit conversion is fundamental and essential to engineering disciplines!