I have experience using a portable 120 volt a/c unit to cool a large machine cab. The hydraulic driven air conditioner was in a back corner and did not blow any air on the operator. The machine had a large generator and a 120 volt outlet in the cab. The portable a/c unit made all the difference. No more complaints from the operator! Also the portable a/c required no maintenance. I can't say the same for the hydraulic unit.