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APRIL 2003

Dry, Drier, Driest: The Right Results
from the Right System

By Archie Johnson


Once an incidental part of an equipment package, dryers have evolved into one of the most important components in today's modern car washes. The continuing rise in wages and employee-benefit rates coupled with spiraling energy costs have brought to light the need for more efficient dryers. To meet that challenge, manufacturers have developed innovative dryers that use less energy, yet dry cars better than ever before.

Car wash operators today have a myriad of good drying systems to choose from. Choices range from dryers with conventional vents to direct-discharge nozzles, from high CFM (cubic feet per minute) to high-pressure dryers, touch or touch-free with oscillating or fixed nozzles, aluminum or stainless-steel construction, and the list goes on. Buyers who ignore these choices and use horsepower or price as their only guideline are often disappointed with their new dryer.


Drying systems should always be designed around specific needs rather than taking the "one size fits all" approach. Chain speed, temperature, floor space, noise restrictions, and available power are just a few issues to be considered when choosing a dryer. Exterior operators usually want cars as dry as possible while full-service operators feel that leaving a little water on the vehicle's surface makes hand toweling easier. Generally, low volume car washes with rollovers and drive-throughs can get acceptable results with a 45-hp three-nozzle dryer. In moderate volume car washes with chain speeds of 60 to 75 cars per hour, a 40-hp to 50-hp four-nozzle dryer would be a good choice. Operators of high volume tunnels with fast chain speeds should consider installing multiple drying arches for best results. The nozzles or vents on this style drying system can be positioned to sequentially strip water top to bottom as vehicles move through the series of arches.

Here are a few additional issues to consider for specific car wash segment applications: Full Service
Operators of full-service car washes are aggressively looking for ways to reduce their operating costs in order to stay competitive. One obvious way is to keep labor at a minimum by having the equipment do more. The cleaner and drier vehicles are when they leave a tunnel, the less labor is needed to get vehicles back on the road. Operators should periodically evaluate the performance of their tunnel equipment, including their dryer. If it's doing all it can and the cars are still coming out too wet, it's probably time to replace it with a new, more efficient drying system.

In-Bay Automatics
Drip space and drip time, important elements in successful drying operations, are of necessity in short supply in-bay automatic applications. To make matters worse, customers don't always drive through freestanding drying systems at a slow, consistent speed. One solution to this problem is to install a large timer display that helps customers pace their vehicle. Another more desirable solution is an on-board dryer that travels with the gantry. In any case, using a good drying agent will certainly improve drying results.

Touch-Free Washing
Customers using a touch-free car wash expect a touch-free dryer. Otherwise, they don't consider it a true touch-free car wash. And even though today's contact dryers are designed to not harm painted surfaces, the customer's perception is that if it touches the vehicle, it's probably going to damage the paint. Rather than trying to convince customers that your contact dryer won't scratch their paint, a safe bet would be to install a touch-free dryer.


Operators should choose a dryer with a time-tested design, one that is produced by a reputable manufacturer that stands behind its products. Manufacturers should be able to verify all performance claims they make. Here are some of the questions operators should ask manufacturers about their dryers before committing to a purchase:

1. How long have they been producing their current dryers?

2. If the selection of a dryer is based on performance claims,     can they back up their claims with reliable and credible proof?

3. How many dryers of their current design are in the field?

4. What are the terms of their warranty?

5. What are some of the options available?


Keeping dryer noise emitted from today's high-CFM dryers down is a real challenge. When huge volumes of air leave a dryer nozzle at speeds in excess of 175 mph and collide with still air, there's going to be noise. Unfortunately, there's not much that can be done about it. However, utilizing rubber motor-mounts, fan-intake covers, and sound coating helps control the whining sound of fans and motors. The only way known at this time to reduce the jet-like sound produced by colliding air is to reduce its velocity. The trade-off, though, is a less efficient dryer - a proposition most car wash operators find unacceptable.


In order for the dryer to move water off the vehicle's surface, the vehicle must first be clean. Any film or soil left on a vehicle's surface will tend to make water cling. In addition, a good-quality drying agent is absolutely necessary to get acceptable results.

Usually, dryer efficiency declines so slowly it's hardly noticeable. It's usually caused by airborne solids such as dust that tend to collect inside blower units. Add to that wax carried by airborne moisture and you have a sticky substance that can collect on fans, nozzles, and inlet screens. When air moves along a rough or uneven surface, it tumbles along that surface causing friction, which ultimately restricts airflow. Other debris can collect on inlet screens to reduce airflow. Dirt buildup on fans greatly reduces their efficiency and can cause a dangerous out-of-balance condition. Just cleaning fans and other air passageways will go a long way to improve dryer efficiency. Maintenance, in other words, is a necessity, which brings us to the final issue we'll consider in this article.


No discussion of dryers, or any other car wash equipment for that matter, is complete without touching on the importance of preventive maintenance. While it's true that dryers require less maintenance than most other car wash equipment, they still need some maintenance to keep them operating safely and performing as they were designed to. Bearings always need occasional lubrication, vents or nozzles have to be checked for cracks or tears, delivery hoses must be inspected for holes, oscillating linkage has to be kept tightened, and pneumatic systems need to be free of leaks. Of course, the amount of maintenance depends on the type of dryer and its manufacturer's recommendations. To ensure that inspections are performed on a regular basis, a weekly or monthly checklist should be developed and followed.

Because the heart of any dryer is its air producers, they should also be inspected on a regular basis. Early warnings of trouble are easily detected by safety and maintenance-minded operators that notice new or unusual noises. A grinding motor noise often means bearings need replacement. An unusual vibration can mean a fan has become out-of-balance and sometimes just removing debris from the fan blades is all that's needed to make it run smoothly again. Fans should also be periodically cleaned and inspected for stress cracks, metal fatigue or loose motor shaft couplers. It's very rare that motors or fans fail without some early warning. By reading the signs and taking corrective action, operators can reduce or eliminate unexpected motor or fan failure that can result in costly downtime.

Today, most operators agree that of all the equipment they have in their car wash, the one component that has the biggest impact on profitability is the dryer. If the dryer is not working well, it wastes electrical power, slows down productivity, and adds to labor costs. Installing the right drying system for the task at hand and following a good maintenance program just about guarantees consistent drying results. Even your pickiest customer will be pleased.

Archie Johnson is founder and owner of Phoenix, AZ-based Superior Car Wash Systems Inc.

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