If there is one part of the job that is often overlooked by customers, it's preventative maintenance on HVACR equipment that is out of sight. Just because it's currently working (and on the roof) shouldn't mean it doesn't need regular check-ups by a service technician. Especially in parts of the country where a lot of dust and debris can get sucked into the equipment, keeping coils clean is an integral part of efficient operation.
For those who keep this kind of equipment operational, here are some of the “must-have” coil cleaning tools to have on hand.
Before we start though, lets go over some of the tools that are NOT recommended, even though they may seem like a good idea.
What Tools NOT to Use
Pressure washer – At pressures starting at 1000psi, the pressure washer may seem like a great idea for cleaning coils, but they often do more damage than you'd think! With just one sweep of the spray, the delicate fins are often damaged beyond repair, making cleaning even less efficient.
(Some) coil cleaning brushes – Not all brushes are born equal. While sites like Amazon may be full of “coil cleaning brushes”, these are often just universal brushes of unknown hardness. Just like the pressure washer, the wrong tool can cause more damage than intended.
Overly harsh chemicals – Every technician will have a favorite brand of chemical, some are designed for simple PM work, and others are powerful enough to strip the top layer off the aluminum. Pick the right chemical wisely and always follow the manufacturer directions for dilution and duration of the soak.
Now on to the tools you WILL want to carry.
What Tools to Use
A good garden hose – This is the first and most important part of any tool kit. While some roofs may have a hose always connected, you sadly can't rely on this. Avoid cheap hoses, or the “as seen on TV” style self retracting hose types as these are not designed for regular commercial use.
A variety of hose adapters and extensions – These are also helpful to carry. Include simple things like shut-off valves and fast connect adapters to make life easier.
An extension wand – Amazingly, this simple tool is often the most helpful thing you'll have in your assortment. It'll make life much easier when dealing with larger package units or to clean drain pans and other parts of the equipment that are hard to reach. You'll find these are your local hardware store for under $20.
Assorted chemicals – Coil cleaning chemicals are available from a variety of brands, and the brand you use may depend on what your supplier has in stock. The always excellent Chris from HVACR Videos is a big fan of the Viper packs from Refrigeration Technologies, and judging by the results in his videos, these are an excellent choice.
Matching chemical spray gun – The manufacturer of the chemicals will provide you with recommendations on how to apply their products. In the example above, Refrigeration Technologies offers a foam gun specifically for their chemicals, complete with a dilution set gauge. Simply fill with the correct dosage, connect to water and spray as needed.
Optional Tools
Optional tools all depend on the locations you work out of, the facilities available and ease of access.
If you know for a fact that there is no available water supply anywhere near the roof, you may have to rely on a portable spray system. These are usually battery-operated and can hold about a gallon of water. They spray at low pressure, so there is no risk of damaging the fragile fins. Most of these systems can also mix the required chemicals as they spray. Do keep in mind that these are often intended for smaller systems, so cleaning a large commercial unit may require several refills. The example above is the CoilJet CJ-125 from Speedclean.
A cordless or corded blower is helpful for cleaning extreme systems where the amount of dry debris is simply too much for a simple cleaning with water. These are better than trying to use a vacuum cleaner as there is less risk of damage. Thankfully, most cordless tool manufacturers will have a blower in their assortment, making it more cost effective as it'll mean you can re-use your existing batteries and charger.