Q: I have many outdoor cleaning projects for which I could use a pressure washer. I am concerned that it will use excessive water and electricity or gasoline. Is this a realistic concern? What type is best?
A: A pressure washer is a real time-saver for outdoor cleaning jobs. Using one can reduce water usage by up to 75 percent as compared to using just a garden hose. For most casual household uses, an electric pressure washer is adequately powerful. I use a 1,950 PSI (pound per square inch) electric model at my home.
The electric cost to run a pressure washer depends upon its size and your electric rates, but about 10 cents per hour is typical.
Some of the electricity a pressure washer uses is offset by the reduction in water usage. Your municipal waterworks has to treat and pump the water to your house, so using less water requires less energy usage by the waterworks.
One reason a pressure washer can use so much less water is its output pressure is about 50 times higher than a garden hose. Cleaners can be added to the pressurized spray to clean faster. The cleaner is poured into a small tank on the washer. Natural, environmentally safe cleaners are available.
The cleaning power of a pressure washer is rated by its maximum pressure and its water flow. Light-duty models have a pressure rating up to 2,000 PSI. Medium-duty, usually gasoline powered, are from 2,000 to 3,000 PSI.
Heavy-duty commercial models are above 3,000 PSI. For regular cleaning of large decks, patios or driveways, a medium-duty model is often recommended.
For a given maximum pressure, models with greater water flow rates can clean larger areas faster.
The water flow is measured in GPM (gallons per minute). Make sure your outdoor faucet can supply enough water flow for a powerful pressure washer. If the water supply is inadequate, the pump can be damaged.
In addition to the power of the pressure washer itself, the type of nozzle on the wand is important for efficient and effective cleaning. The spray from various nozzles can range from a pinpoint zero-degree to a 40-degree pattern. Spray patterns under 20 degrees can strip paint, cut weeds from patio cracks, etc. Be careful because they can cut your skin like a knife.
A 40-degree spray is a good starting one to use for general cleaning. It cleans well, but is not so strong that it literally destroys the top wood fibers on a deck. An adjustable turbo nozzle is also good to have. This can be adjusted to various spray patterns depending upon the cleaning job. The spray pattern rotates to clean larger areas faster with less water.
James Dulley is a mechanical engineer and do-it-yourselfer. Send questions to James Dulley, The Sensible Home, St. Petersburg Times, 6906 Royalgreen Drive, Cincinnati, OH 45244. Visit his Web site at www.dulley.com to tour his energy-efficient home, post questions for other readers and find other information.