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Pressure Washers and Steam Cleaners are designed to save time and money, so it's very important that you choose the right model. Over-sized models waste cleaning power...undersized models waste time. By combining pressure, volume, heat and chemicals pressure washers can clean so much faster than manual methods (sometimes making the cleaning job go six times faster) that the labor savings alone can pay for the machine.

In order to make an informed decision about what type and style of pressure washer to choose, we here at Jenny, have attempted to compile and condense some of the information we have learned since inventing this industry in 1927. We attempted to start with basic principles of cleaning and expand them in stages to allow a more informed decision to be made. (Please read "Introduction to Pressure Washers and Steam Cleaners")

There are two primary and most basic factors that must be considered in determining the correct pressure washer.

1. Type of cleaning.
2. Amount of Cleaning.

The type of cleaning that needs to be performed will determine the style of machine that will be necessary to perform the cleaning job. The amount of cleaning to be done will help determine the overall size of the unit. After determining the type and size of the unit you need a few other factors need to be considered. Pressure washer units, are offered with different heating sources (or none at all), weights, sizes, and overall construction.

Type of cleaning (please see note)

• Earth dirt, road dirt, mud, etc. - Cold pressure washers are at their best when used on earth dirt, road dirt, mud, etc... generally where grease and oil are not a factor. A cold pressure washer with the help of a soap will be able to wash construction vehicles, clean sidewalks, parking lots, swimming pools, and cleaning jobs of this type and nature. Cold pressure washers are not the ideal choice for washing grease or grime (Grime is when you have dirt that is clinging to or ingrained in a surface). A cold pressure washer may move the grease and grime around but it will not clean the surface as it should, without the use of a very aggressive cleaning chemical. Cleaning a fifth wheel on a tractor-trailer would be a good example, the heavy grease is more likely to splatter and smear than to come clean.

• Medium oil, gum, grease, and grime - Hot pressure washers are best suited for cleaning large areas quickly and where the type of cleaning is typically light to medium oil, gum, grease, and grime. The heated water in a hot pressure washer aids in the loosening of the dirt, and when soap is added, the dirt will come free of the surface. These machines will clean heavy grease deposits and grime, but will leave a slight grease or oil residue. A good hot pressure washer application would be a tractor-trailer. There are large areas that need to be cleaned, but the dirt is not caked on or very thick.

• Grease, oil, animal, vegetable, or, mineral, contaminates - Steam cleaners perform best when used on grease, oil, animal, vegetable, or mineral, contaminates. This is not to say that steamers will not clean other contaminates and surfaces. Steam will clean more thoroughly than a hot pressure washer, but will take longer on large areas. Steam cleaners have the capabilities of emulsifying an oil based grease or grime using the 325ƒF temperature. With the aid of soap chemicals (remember that soaps get more aggressive as temperatures increase) the job becomes faster and easier. Because of the high temperature it will also melt down such substances as honey, tar, most glues, etc... Steam cleaners also have excellent sanitizing capabilities because the ultra high temperature water will kill most germs, bacteria and viruses.

• Continually changing applications - Combination units shine when the cleaning applications are continually changing and vary from one type of dirt to another. With a combination unit you have the best of all the other three units listed above in the same unit. So if you want to clean mud, leave the unit in cold-water mode, cleaning a truck, switch on the heat, and have a build up of grease and oil underneath the hood, switch the machine to steam.

NOTE: These are general guidelines presented to aid you in the selection of the pressure washer type that will work best for your needs. Please consult a professional pressure washer dealer to discuss what type of unit best suits your individual specifications.

Amount of Cleaning

After determining the overall type of machine (i.e. Cold Water, Hot Water, Steam Cleaner, Combination Unit) there are several other variables that determine the amount of cleaning a pressure washer unit can achieve. They are:

A. Pressure
B. Flow Rate (Volume)
C. Horsepower

The two most influential variables after the type of machine has been chosen are pressure and volume. These two factors will influence how quickly a cleaning job can be completed and how much the unit will cost.

• Pressure, typically rated in PSI (Pounds per Square Inch), can seem to be the most impressive of the factors because of the large number associated with it. Pressure washers typically have pressure ranges from 750 to 5000 PSI, and that sounds really powerful. Understand, that the primary reason for the pressure is to help break the bond between the dirt and the surface being cleaned. Anything more than that is unnecessary and will just blow the dirt all over or cause damage to the surface being cleaned. Also, the higher pressure through the nozzle will cause the spray to atomize and become less effective for cleaning.

• Volume, rated in GPM (Gallons Per Minute) on the other hand is what carries or flushes the dirt away. How fast dirt can be removed will be more influenced by the volume than by the pressure once the bond between the dirt and surface has been broken. Pressure washers appear to consume a lot of water, but this is not the case at all. The average pressure washer uses approximately three to four gallons of water per minute, whereas, the average garden hose puts out somewhere between six and eight gallons of water per minute. Using a pressure washer to clean is typically much faster and also helps save water.

• The Horsepower of a unit will determine a number of different factors. The maximum pressure and volume, the voltage it can or cannot run on (i.e. 115V, 220V, etc...) and the amperage that it will draw. Typically the more horsepower a machine has will allow for higher pressures or volumes or a combination of both.

The pressure, volume, horsepower relationship holds true for cold and hot pressure washers, but not for steam cleaners. Steam cleaners typically are very low pressure and attain their cleaning power by using the vapor expansion of 325ƒF superheated water. Typically most steam cleaner horsepower ranges are from 1HP to 2HP. The unit's horsepower requirement will be determined directly by the volume and pressure.

The simplest formula is:

Electric Motor Horsepower = (PSI X GPM)/1460
Gasoline Engine Horsepower = 1.5 X (PSI X GPM)/1460 = 1.5 X Electric Brake HP

Note: This formula is the only true way to measure and compare different units i.e. two cold pressure washers or two hot pressure washers. However, it is not useful when comparing a cold pressure washer to a hot pressure washer or steam cleaner, since now there is the addition of a water heating system and in the case of a steam cleaner, the cleaning type is different. (See "Introduction to Pressure Washers and Steam Cleaners")

A good example of the pressure volume relationship is to start with a 2HP motor. The motor is capable of producing 1400PSI at 2.1 GPM or 1000PSI at 3.0 GPM. With a standard pressure washer nozzle, the 3 GPM flow will have a greater surface impact than will the 2.1 GPM. The horsepower rating of the unit will be a limiting factor in the amount of work that a pressure washer can accomplish.

Other Factors

A. Portability or Mobility
B. Heating Type
C. Size and Weight
D. Construction (Light-Duty or Heavy-Duty)

• Portability or Mobility - Determine whether or not the unit will need to be moved around your facility or if it will be a stationary unit. This will aid in determining other factors such as heating type, size, weight, and construction of the pressure washer.

• Heating Type - There are several different heating types that are available today. They are:

1. Oil - Diesel, Fuel Oil, Kerosene
2. Gas - Natural or LP
3. Electric

Choosing the correct heating method will be based on a number of factors, such as, the overall cost of heating, where cleaning is to be performed, the conditions of the cleaning environment, whether fumes are acceptable, and is the machine to be portable.

Oil Fired
Using diesel, fuel oil, or kerosene to heat the water in a pressure washer is the most popular form. It allows the machine to be very portable and these types of fuels can be readily found almost everywhere.

Gas Fired
Gas fired machines can be configured to burn either Natural Gas or LP gas. In most cases, these machines are stationary and are hard plumbed into the gas system of the building where they are located. They are typically the least expensive machines to operate overall.

All Electric
All electric machines use electricity to heat the water. They are ideally suited for applications within plants where fumes may be a problem and/or portability is necessary. These machines use high voltage and draw high current.

• Size and Weight - Pressure washer units come in a great variety of sizes and weights, which depending on mobility requirements of your cleaning needs, may be an important consideration. Higher pressures and volumes will require the unit to be larger in size and heavier in weight since horsepower requirements, pumping systems, chassis construction, combustion systems, electrical components, etc... will have to be larger to accommodate these increases. In cold pressure washers, these factors will not have as great an effect as in hot pressure washers and steam cleaners since the combustion system is not there.

• Construction - Pressure washers come with a variety of options in their construction. Knowing where, how, and how often the unit will be used will aid in determining if you need a heavy-duty model or a light-duty model. If the unit is to be used less than 5 hours a week, a light-duty machine should be sufficient. Anything more than 5 hours per week, then an industrial/commercial grade machine will be necessary.

Pressure Washer Buying Guidelines

Understanding the type and amount of cleaning to be done and the different types of machines will help in deciding which machine to purchase. It will, however, not help determine from whom to purchase the unit.

It is worth noting that the price of pressure washer cannot be based solely on the up front purchase price of the unit. The price of any item should be based on the overall cost over an extended period of time. Inexpensive units are deigned to be disposable, like lighters.

There are some 250 different supposed manufacturers of pressure washers in the U.S. today and any one of them will be more than happy to sell you a cleaning unit. Before purchasing any unit from and any manufacturer, there are several factors that should be considered:

1. How long has the company been in business.
2. Have you ever heard their name before.
3. Do they have an actual manufacturing plant or are they just resellers or have machines private labeled for them.
4. Do they manufacture a full line of machines (cold, hot, steam) or just one.
5. Do they carry a complete line of cleaning chemicals.
6. Do they carry parts and accessories for their machines.
7. Do they have a good distribution network.
8. Do they have a good service network.
9. Are they knowledgeable about their product.
10. Are they knowledgeable about cleaning in general.

Whatever your cleaning need, there is a Jenny to do the job. Backed by a company with over 70 years of manufacturing and cleaning experience and one of the largest product offerings in the business, we are ready to serve you. Why not call us to discuss your cleaning needs and how we can help solve them.