Car Washes

A car wash is a facility used to clean the exterior and, in some cases, the interior of motor vehicles.

While there are many different types of car washes, most in the US fall into three main categories:

Self-service facilities, that are generally coin-operated, where the customer does the washing
In-bay automatics, which consist of an automatic machine that rolls back and forth over a stationary vehicle - often seen in service station washes
Tunnel washes, which use a conveyor to move the vehicle through a series of fixed cleaning mechanisms.
Mechanized car washes, especially those with brushes, were once avoided by some meticulous car owners because of the risk of damaging the finish. Paint finishes have improved as have car washing processes, and this perception of vehicle damage is much less today. It was, however, the motivation behind the rise of the "brushless" (cloth), "touch-free" (high-pressure water), and most recently, brushes which are made of closed cell foam, car wash facility.

In a modern car wash facility, whether automatic, in-bay automatic or self-serve, soaps and other cleaning solutions used are based on milder acids and alkalies designed to loosen and eliminate dirt and grime. This is in contrast to earlier times, when hydrofluoric acid, a hazardous chemical, was commonly used as a cleaning agent in the industry. There has been a strong move in the industry to shift to safer cleaning solutions. Most car wash facilities are required by law to treat and/or reuse their water and may be required to maintain waste-water discharge permits, in contrast to unregulated facilities or even driveway washing where waste-water can end up in the storm drain and, eventually, in streams, rivers and lakes.

A simple and automated type of car wash that is typically coin-operated or token-operated self-service system. Newer self-service car washes offer the ability to pay with credit cards. The vehicle is parked inside a large bay that is equipped with a trigger gun and wand (sprayer) and a scrub foam-brush. When customers insert coins or tokens into the controller, they can choose options such as soap, tire cleaner, wax or rinse all dispensed from the sprayer, or scrub the vehicle with the foam-brush. The number of coins or tokens inserted determines the amount of time customers have to operate the equipment, however in most instances, a minimum number of coins are necessary to start the equipment. These facilities are often equipped with separate vacuum stations that allow customers to clean the upholstery and rugs inside their cars. Some self-service car washes offer hand-held dryers, a somewhat new feature.

The first conveyorized automatic car washes appeared in the mid 1940s. Conveyorized automatic car washes consist of tunnel-like bays into which customers drive their cars. Some car washes have their customers pay through a computerized POS, or point of sale unit, also known as an "automatic cashier", which may take the place of a human greeter. The mechanism inputs the wash PLU into a master computer or a tunnel controller automatically. When the sale is automated, after paying the car is put into a line-up often called the stack or queue. The stack moves sequentially, so the wash knows what each car purchased. After pulling up to the tunnel entrance, an attendant usually guides the customer onto the track or conveyor. At some washes, both tires will pass over a tire sensor, and the system will send several rollers. The tire sensor lets the wash know where the wheels are and how far apart they are. On other systems the employee may guide the customer on and hit a 'Send Car' button on the tunnel controller, to manually send the rollers which push the car through.

When the customer is on the conveyor, the attendant (or signage) will instruct the customer to put the vehicle into neutral, release all brakes, and refrain from steering. Failure to do so can cause an accident on the conveyor. The rollers come up behind the tires, pushing the car through a detector, which measures vehicle length, allowing the controller to tailor the wash to each individual vehicle. The equipment frame, or arches, vary in number and type. A good car wash makes use of many different pieces of equipment to thoroughly clean the vehicle.