Hot Or Not?

Go into any rental business and you will likely find a pressure washer or two... or a dozen. Their task is not glamorous and they don’t inspire oohs and ahhs from customers. But you would be hard pressed to find a tool more needed by so many for so much.

Yes, pressure washers are used for everything from cleaning a patio or deck to degreasing industrial food processing equipment. They are used by contractors, farmers, fleet operators, factories, municipalities and more.

Pressure washers come in two distinct varieties: hot-water and cold-water. While similar in their overall purpose, they differ in the applications they are best suited for. Hot-water pressure washers excel in removing greasy substances from surfaces quickly. They are bigger, more complicated machines that cost significantly more than their cold-water brethren. The question is, do they make sense for your rental inventory?

The heat is on

“Typically, in regards to hot-water washers, you think of applications where grease, oil or road film needs to be removed,” says Keith Price, vice president of sales for Shark Pressure Washers. “A hot-water washer will produce the same psi and gallons per minute as a cold-water washer, but when the burner is activated, it produces up to 200F-degree cleaning, which attacks [dirt and grime].”

Ollie Nielsen, director of sales and marketing with Alto Cleaning Systems Inc., notes that while hot-water pressure washers will clean faster and more thoroughly than cold water, they do require another source of fuel to heat the water and they are also larger and heavier than cold--water units, making them more difficult to transport.

“A cold-water unit is easier to operate and has fewer maintenance concerns, but cleaning times will be longer,” adds John Lembezeder, national sales manager at Mi-T-M Corp. “Anytime hot water might damage the surface being cleaned, cold water would be the solution.”

According to Price, there is a growing trend for rental centers to stock trailer-mounted hot-water machines with on-board water tanks for large contractors who require a lot of equipment cleaning. “A hot-water washer has the versatility of providing both hot- and cold-water cleaning. They will provide more effective cleaning, but if all you’re removing is dirt and mud, then it’s overkill.”

He adds, “Because of their [compact] size and weight, cold-water machines are better suited to homeowners and small businesses. Many models are designed to fit in the trunk of a car, which expands their market potential dramatically. Hot-water machines typically are attractive to big businesses and contractors who have more serious cleaning needs.”

When deciding whether to incorporate hot-water pressure washers into your fleet, cost will inevitably come into consideration. “The cost of cold-water machines has stayed level or dropped over the past decade, making them an excellent value,” says Price. “Good, heavy-duty, engine-drive machines are priced well below $1,000 and are more reliable than ever before. Depending on the configuration, it’s not uncommon to pay more than double for a hot--water pressure washer. The real benefit to hot-water pressure washers is that they command double the daily rental price and they almost always are rented for longer periods of time.”

Lembezeder adds, “Quality is a significant factor in the price of a pressure washer. You can expect cost differences between electric and gas, and hot and cold washers. Also, the size of the pressure washer determined by its horsepower will impact the price.”

Nielsen explains that pressure washers most often range between 5.5 and 20 horsepower and 1,500 to 5,000 psi. The most common rental machine is the 13--horsepower, 3,000--psi unit.

While the size of a pressure washer is generally measured in water pressure by pounds per square inch, this can be misleading. There is a tendency to look only at psi and not the volume of water or gallons per minute (gpm).

Actually, water volume is as important as psi in determining the cleaning power of a pressure washer. Cold--water units will generally require more water and pressure to achieve the same results as a hot-water machine.

More to maintain

Cold-water pressure washers are fairly simple; an engine powers a pump which propels presssurized water through a small opening. Hot-water units are a bit more complex. “Water enters a pressure washer from a spigot or tank via a garden hose. It first passes through a high-pressure pump, which speeds water on its way through a heating coil, consisting of up to 200 feet of half-inch, schedule 80, steel pipe or tubing,” explains Price. “The helical or circular winding configuration allows the water to get maximum exposure to the flame (fueled by diesel oil or natural gas/propane) as it roars through the center of the coil. By the time the water rushes out of the coil and through the wand and nozzle, it will have reached temperatures of up to 200F degrees.”

Lembezeder suggests, “Depending on your water source, it is recommended that you delime your coil on a regular basis. When winterizing your hot-water washer, it is important to protect your unit by either running compressed air into the system to remove all of the water or running a mixture of antifreeze solution through the system.”

He notes that with hot--water units, it’s also necessary to winterize the coil using one of the above procedures.

“Other maintenance issues with a hot--water washer such as burner air adjustment, testing water and fuel pressure, testing water temperature, inspecting burner fuel pump internal filter and replacing the fuel nozzle should be done by an authorized technician,” Lembezeder says.

According to Joyce Lequesne, service manager at Ben’s Rent-All in Las Vegas, hot-water pressure washers might require more maintenance than a cold-water unit, but they still aren’t what she would consider “high-maintenance” rental items. In fact, Ben’s Rent-All stocks an equal amount of hot- and cold-water machines. The hot-water units come in especially handy with the amount of restaurant business in the Las Vegas area.

“Hot-water pressure washers are one of our better rentals,” she says.

Additional controls and features found on hot-water units do add to the maintenance concerns, however, says Price. “Major manufacturers now offer field and factory training schools to rental operators who want to have their mechanics up to date on both hot- and cold-water washers. This is growing in popularity because many rental centers are actively marketing new equipment, as the profit margins are excellent at the retail level. The aftermarket for repair parts, accessories and detergents is very good.”

In the end, the decision of whether or not to add hot-water pressure washers to your fleet is one dependent upon your customers’ needs and your ability to justify the expense and additional maintenance. There is no doubt about their effectiveness and versatility in the war against dirt.

Hot water--Dirt’s #1 enemy

According to information supplied by Shark Pressure Washers, there are three key elements in the successful removal of dirt and grime - heat, agitation and soap.

Heat-Creates a high-speed molecular action that causes the cleaning agent to be more active and reduces water’s surface tension so it can effectively penetrate grime at the molecular level.

Agitation- Describes the impact that comes from the water volume and water pressure hitting the surface, similar to the action of your hand scrubbing a dinner plate in your kitchen sink.

Soap- Chemically breaks the bond between dirt and surface. Detergents use softening agents, technically referred to as surfactants (an abbreviation for “surface reactive reagents”) to emulsify the oil and grease. Once the oil and water are able to mix, forming an emulsion, the dirt--still clinging to the oil and grease-- can be carried away in the wash water.

“If you’re cleaning engines, automotive parts, or anything with oil and grease, you’ll need hot water,” says Keith Price, vice president of sales for Shark Pressure Washers. “Like the dishes in your sink, hot water melts away grease and grime; cold water only pushes it around.

“On the other hand, if you’re simply blasting away sand, caked-on mud, or even stripping paint, a cold-water pressure washer will work just fine. Combined with a detergent, a cold-water pressure washer can be very effective in many applications.”

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