Professional Carwashing & Detailing

Suck it up

October 11, 2010

Many carwash operators throughout the industry are offering free self-serve, post-wash vacuums to their express customers. This model is showing up in operations of all sizes, from small neighborhood washes to new ultra-modern mega washes that can accommodate upwards of 1,000 cars per day.

In these large express washes, traditional greeters are replaced by automated touch-screen kiosks with computer controlled swing-arms. Traditional employee-operated vacuum islands (pre-wash) are giving way to free central self-serve vacuum stations (post-wash).

The result is a fully automated super wash that serves a high volume of customers with minimal labor. Customers select and pay for their washes at touch-screen entry kiosks. They remain in their cars through the tunnel and then drive to the complimentary vacuum station. From entry to exit, customers get a quality wash and the use of professional vacuums without ever talking to, or waiting for, an employee. This model is very attractive to operators because it maximizes traffic flow while minimizing costs.

So how is the vacuum industry responding to this demand for multiple, self-serve vacuum stations?

Some manufacturers are answering the call with more horsepower.

These manufacturers offer multiple vacuum hoses — or drops — powered by a series of central vacuums that run non-stop during business hours. This follows traditional vacuum methodology where the solution to more drops is simply more horsepower. While this model gets the job done, it also means higher energy consumption, higher electric bills and a lot of wear-and-tear on the equipment.

Others are responding to the demand for more vacuum drops by breaking from conventional thinking. Through the use of advanced technology these manufacturers are offering vacuum-on-demand systems. These systems supply suction to match customer demand at any given time. Operators enjoy immediate cost savings on energy bills and return-on-investment is realized in months, not years.


Let’s look at a hypothetical carwash operator whose market calls for a maximum of 48 vacuum drops to be used simultaneously.

Traditional model
The operator may offer his customers 48 drops by installing eight standard 25hp central vacuums, each serving 6 drops. That’s 200 horsepower producing suction for 48 vacuum drops. When customers finish the wash and dry process, they drive to the vacuum area and find all eight central vacuums running and all 48 drops waiting for them. They simply choose an open spot, pick up a nozzle and begin vacuuming. They vacuum for as long as they like and return the nozzle when done.

In this scenario, the operator runs all eight vacuum producers from open to close, every day the wash is open. No matter how many customers are actually vacuuming, all eight systems are operating. The demand on the equipment and the electrical usage (kilowatt hours) would be approximately the same whether there are 48 customers or one. The exact cost of operation depends on true usage on the system and the region, but the national average is 9 cents per kilowatt hour (see for more info).

If the operator chose to have an employee on-site, he or she could monitor traffic flow and shut down or start up the central vacuums as needed. While this appears to be an effective way to manage electrical costs, it’s actually counterproductive. The power consumption or “spike” required to cold-start a vacuum producer usually negates any potential savings. Plus, it would require closing and opening different vacuuming zones and controlling traffic flow.

The layout and engineering for these “always-on” systems are fairly straightforward so installation methods are not critical. But as described above, energy costs and wear on the equipment are substantial.

The alternative
By using a technologically advanced system to provide vacuum-on-demand, the scenario changes dramatically. A vacuum-on-demand system accommodates the same 48 simultaneous users with just four 30-hp central vacuums. This break from conventional wisdom achieves the same goal of 48 drops, but actual power consumption (kilowatt hours) is based entirely on demand. If business is slow to moderate, only one or two vacuum producers run. If business is booming and all 48 drops are in use, all four vacuum producers run at full speed. Since each of the four vacuum producers only runs when needed, equipment life is extended and energy costs are minimized.

How it works
When the first customer of the day arrives, the vacuum-on-demand system is off. The customer activates the vacuum by entering a code, inserting a token, driving over a sensor or depressing a button. One vacuum producer starts up (in soft-start mode to prevent a power spike) and suction is opened only to the selected hose drop. The motor runs at the appropriate rpm’s to provide suction to that one drop (approximately 80-90 cubic feet per minute).

When a second customer activates the drop, suction is opened to that second drop. This process continues until greater rpm’s are needed. At that point, the vacuum producer “revs” up and increases rpm’s to match customer demand. This process continues to step up suction until demand increases enough to soft-start a second, then a third vacuum producer, until finally all four vacuum producers are running.

As demand decreases, rpm’s are reduced accordingly and the vacuum producers shut down successively. The four vacuum producers can be programmed to alternate and “take turns” being the primary vacuum. This ensures even wear on all four motors. In this scenario, electrical usage is dictated by the number of users on the system.

Vacuum-on-demand systems also allow carwash operators to control the length of each vacuuming session and prevent lines at the vacuum stations. Since the on-demand system controls suction to each hose individually, operators can pre-determine how long each customer vacuums free of charge. With the proper equipment, customers can opt to vacuum longer by inserting coins, bills or credit cards in the vacuum station.

Why it works
It’s far less expensive to run two computer-controlled 30-hp vacuum producers at half speed than to run one standard 25-hp vacuum producer at full speed. In fact, it requires 50 percent less energy. Vacuum-on-demand takes full advantage of this and provides tremendous energy savings to operators.

Motor controls simultaneously manage voltage, hertz and amperage in series. This precise balance dramatically reduces kilowatt usage (and saves operators real dollars every hour the system is running).

The beauty of vacuum-on-demand is that the only time all vacuum producers are running at maximum speed is during the peak of business. (Translation — the only time the operator pays to run all four vacuum producers is when the wash is making the most money.)

  • Energy consumption is proportionate to traffic flow;
  • Wear-and-tear on the vacuums is reduced and equipment life is extended;
  • Carwash operators can determine how long customers can vacuum; and
  • The system is efficient whether there are 48 customers or one.

While this discussion focuses on large, high volume washes, vacuum-on-demand and its benefits are actually available to carwash operators with any size wash.

What it takes
Initially the investment for a vacuum-on-demand system is slightly greater than a conventional system because of the technology and engineering involved. The vacuum producer, debris separating system and piping system must be engineered precisely.

A successful vacuum-on-demand system must be installed properly, following the manufacturer’s exact specifications. This will probably require a site-visit from the manufacturer during the installation and start-up process.

Despite greater installation costs, the return on investment is faster with vacuum-on-demand than with a conventional system because of energy savings —savings that are reaped immediately and every month thereafter in real money.

Exact ROI varies by area according to energy costs, but a knowledgeable vacuum manufacturer should be able to run the numbers and provide an accurate cost-savings analysis.

Steve Tucker Jr. is president of G2 Equipment LLC, manufacturer of AutoVac industrial vacuums, parts and accessories which is headquartered in San Diego, CA. Tucker has more than 15 years’ experience in the carwash industry and can be reached at