Air Dyers put my car wash on the map!! I installed Diskins Air Shammee II at my car wash in December 2018. Cost $20,000 ($2k per bay x 5 bays + $5k for electrical panel upgrade + $5k for installation. Based on hour meters, this was paid off within 7 months. I installed the single motor 4.5 HP, 3 phase electrical. Do yourself & customers a HUGE favor & replace Diskins nozzles with Air Logic ones. They provide 25% MORE air with less maintenance. On Diskins nozzles,, the rivets fall out & baffles hold back the air, causing the hoses to split or hoses to blow off the boom. Your customers will LOVE the Air Dyers!! 
We have Air Logic Air Shamee2 purchased from KR. Tried both the attic mount and the bay mount. Bay mount is much easier to service but both units are great.
The single motor is DEFINITELY the way to go. When I was looking to purchase Diskins dryer they sent me to 2 car washes that used their 3-motor system (before they came out with 1-motor system). I tried them and barely any air was blowing out. I called Diskin and they said 1 or 2 of the motors was probably out. The 1-motor system will either blow or be dead, no confusion!
Based on feedback from my customers (4 years of use), they want MORE AIR. Comparing my notes from past brochures Diskin uses 4.5/5 HP motor that produces airflow 320 MPH, Carolina Pride uses 3 HP motor that produces airflow ~ 180 MPH and JE Adams (Turbo Towel) uses 120 Volt motor that produces airflow "that exceeds 200+" Customers also want a nozzle thats easy to hold WITHOUT a trigger they need to hold in.
The Carolina Pride Turbo Dry III says it uses a 4 HP motor but maybe the earlier ones were smaller HP?
