66524 | I am thinking the 2 (18") are for outside inlet air and outside discharge air .That makes sense.The conderser air flow is about 15% more in volume than the condition inside air .Nominal 400 cfm per ton x 5 = 2000 cfm conditioned air and about 2500 cfm of condenser air flow.18" round pipe is 1.76 square foot .So 2500/1.76 = about 1500 ft/minute velocity which is obtainable with a squirrel cage blower.If that is your situation ,just be sure and seperate the inlet and exit with deflectors to prevent short cycling of the discharge air as it exits the wall .I only mentioned water cooled because I went to there site and notice they make water cooled units.They surely make both water and air cooled also.Water cooled is just so convient for manufacturing . Hope this helps |