ECN Forum Forums Technical Discussion Electrical Theory and Applications Air Conditioning

The common term is metric. SI is short for system international (actually the french words). While there have been attempts to force it on the U. S., the public has overwhelmingly rejected it. It has crept in to some places. The car industry is mostly metric and we buy 2 liter bottles of soda but people are too used to the English system to change quickly. I've never understood the whole ton/BTU thing. You've got a unit in your house. The bottom part delivers heat in BTUs and the top part takes away heat in Tons. Oh well, thats what those nifty calculators are for.

correct me if I'm wrong but the BTU = British Thermal Unit = the first guys to quantify the phenomina so they get the imortal acronym. Tons = tons of ice it takes to absorb x amount of heat in BTUs over I think 24 hour period, 1 ton = 12000 BTUs. I think the ton is American and somehow is based on all the ice we would store up from the winters. I personally disslike the mix of standard and metric.

[This message has been edited by JohnnyB (edited 10-04-2003).]

Hey, if you really want to get into some interesting math, lets talk about psycometrics and the air side calculations. Then we can get into the amount of water that standard air can hold at a given temperature and how many BTU's of latent heat load its going to put on the air conditioner. OH, and lets get a pressure temperature enthalpy chart out to show the refrigeration process line for the formentioned explanation of the refrigeration cycle.

Jonny: Don't forget to check the superheat and subcool to make sure the system is charged correctly. Resurrecting memories of college thermodynamics!