Practice Tips #53: How to Get the Most Life From Your Compressor

The compressor is one of the most important pieces of equipment in the dental office. In previous issues, we’ve discussed the importance of routine maintenance to keep your compressor running well. Not only will this help extend the life of your compressor, but it will also save money by saving energy.

Compressors use electricity, the harder they work the more electricity you will use. In addition to routine maintenance, how else can you reduce the load of your compressor and save electricity?


Air leaks mean your compressor runs more frequently (in extreme cases constantly), which can not only lead to a shorter compressor life, but it is a tremendous waste of power. A telltale hiss will usually be your first sign of an air leak, but how do you find the leak so you can correct it? A simple method is to coat suspect joints or fittings with soapy water. Mix a solution of about 25% dish soap and 75% water and brush it onto suspect areas. If there is an air leak, the solution will bubble.

Worn or cracked hoses should be replaced. If the leak is near one end, you may be able to trim the hose and re-attach with a fresh end.

You should use Teflon tape where possible for threaded fittings, although Loctite (usually the yellow or blue formula) will work well too. Barb threads should be sealed with a washer gasket.

Worn o-rings can also result in leaks. Lubricate o-rings regularly with silicone lubricant to keep them supple and well sealed. Sometimes replacements are in order. Keep spares on hand.


Clogged lines can put strain on your compressor. A classic symptom of a clog is rapidly dropping pressure.

It’s common to have good pressure, but as soon as you use your handpiece the pressure rapidly drops off. You hang your handpiece up and a minute later you again have good pressure, but it again drops off quickly. This is classic obstruction behavior.

The line is obstructed and you will have minimal air flow. While not in use, the “dribble” of air builds up into solid line pressure, but as soon as you begin to use it the pressure drops off, as the obstruction prevents maintaining line pressure for a prolonged period.

To find the clog you need to trace the line backwards from the point you’ve noticed a performance drop until you find solid consistent line pressure. The clog will usually be at the next junction, AFTER you’ve found good pressure again.

Make certain to check your filters regularly (we recommend every month) to help prevent clogs. You should have filters in your junction box.


While you’re in your junction box, you should double check your pressure. Most units recommend running at 80 psi of air. You should have a regulator with a gauge on it (similar to that pictured above) to indicate what your air pressure is. Excessive pressure can cause your compressor to run too frequently. Verify correct pressure on the gauge and then hold down the air button on your syringe and watch the gauge. Does the pressure hold steady? Does it decrease? If the pressure drops off, check for clogs (as above), but also check your compressor. The regulator in the units can only step the pressure down. It’s very important that you have your regulators set to a pressure less than the output of your compressor; otherwise they may not actually be controlling pressure at all. To provide a steady 80 psi in the ops, your compressor should be set to 90-100 psi. Of course, you don’t want your compressor set too high, so keep it within this range (barring special high-pressure equipment). If your compressor is set lower than 90-100psi, you will almost certainly fail to achieve proper pressure in your ops and can encounter a host of problems, like cross over.

Many things in the dental unit are air activated (including your water), so it’s important that your air pressure isn’t too low (actually, this is something we see more often than excessive pressure), but it’s good to avoid excess; “more” isn’t always better.

Of course, as with most things, try to make sure to turn units off when not in use to conserve power. If an op will be out of use for more than an hour, shut the unit off using the master toggle on the front of the unit. This will shut all air & water into the operatory off.

PROBLEM: Moisture

Moisture can have a horrendous effect on your compressor. Moisture can lead to corrosion of components, loss of pressure, and even cross-over affecting other equipment downstream. Make certain you have proper filtration and drying systems in place.

Many filtration and drying systems will have moisture indicators to show if it’s time to replace elements. Check these indicators regularly and keep spare filter elements/drying media on hand.

After changing filters, it’s a good idea to check indicators again to verify that the excess moisture is not in the system from some other source.

Many compressors will have a tank drain. Make sure this is operating properly and is drained every day.

Of course, it’s also important that you get the correct compressor for your needs in the first place. A compressor that is too small will be working overtime and is likely to fail quite early. When purchasing a compressor, always pay attention to the user ratings. Dental compressors are rated for a number of “users.” This number is equal to the number of dentists that can be using a unit powered by the compressor at once. Hygienists are considered 1/2 user for purposes of compressor capacity. So, if you have a compressor rated for 3 users, you can have one dentist and 4 hygienists (1 + 4 x 1/2), or 2 dentists and 2 hygienists, or any of a number of other permutations.

The compressor is the heart of the dental practice, getting the most out of it will not only save by helping to minimize down time, but can help you save electricity and keep it beating for the life of the practice.  So be sure to keep up with routine maintenance, watch your pressure at the compressor and in the ops, listen for leaks and make sure your air is dry.


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