AFE May/June 2012 : Page 13

So, how much water is that? Th e average for all buildings across North America is 0.5 gallons of condensate per hour for every ton of air-conditioning operation. Th is works out to 6,000 gal-lons per day (1.2 million gallons per year) for a building with an average cooling load of 500 tons and a 200-day cooling season. You can determine the amount available for your building by doing a few simple calculations. Basically, the amount of moisture removed by the coil (at these operating conditions) is found by multiplying the mass fl ow rate of air through the coil by the diff erence between the humidity ratio entering and leaving the coil. Th e humidity diff erence between en-tering air and leaving air must be looked at and calculated. Sample conditions would be: 0.0112 -0.0087 = 0.0025 lb of water/lb of dry air. Th erefore the moisture 1 removed by the coil would be calculated as follows:  DIAGRAM 1 (6,100 ft 1 /min x 0.075 lbs/ft 1 ) x 0.0025 lbs of water/lbs of dry air = (1.14 lbs of water/ min) / (8.33 lbs/gallon) = 0.14 gpm or 8.24 gallons/hour. Once you’ve decided you have enough of this high-quality water to make reclaiming it worthwhile, how do you do it? In most cas-es, it is a fairly straightforward process. Th e AHC is collected in a small collection tank equipped with a fl oat-activated submers-ible pump. Th e collected condensate is then pumped directly to the cooling tower. Or it can be pumped into the cooling tower water supply line. (See example in image one.) LEL International, Inc. Industrial & Powerhouse Equipment We buy and sell mechanical, industrial and powerhouse equipment including chillers, air compressors, cooling towers, boilers, tanks, generators, electrical gear and more around the globe . Tel: 864.699.9605 Fax: 864.751.4296 www.lelinternational.com Sales Contact: Chad Blackwell chad@lelinternational.com 792 John B. White Sr., Blvd. Spartanburg, SC 29306 *Warehouses located in Modesto, CA, Spartanburg, SC and Dallas, TX May | June 2012 ■ Facilities Engineering Journal ■ www.AFE.org 13