Packaged rooftop units are the workhorses of the industry. Subjected to the extreme temperatures found on the roofs of malls, retail spaces, offices, and the like, these pieces of equipment just keep chugging along, season after season — at least for a while.

The day eventually comes when the owner actually remembers what’s keeping his space warm and/or cool: that box on the top of the roof that now is not working. Panic ensues, followed by a desperate call to a local contractor.

Had the owner taken the time to maintain his rooftop unit properly, this may not be the all-too-common scenario. Simply having a qualified contractor come out and service the rooftop on a regular basis could head off many breakdowns.

But many owners look at preventive maintenance as being too expensive and unnecessary. Some fail to see the long-term benefits of a preventive maintenance program, such as lower energy costs and fewer breakdowns.

Joe Gennari watches a technician perform an inspection on a rooftop unit to make certain the preventive maintenance was done properly.

Service contract mandatory

These types of system owners can be a headache for contractors. But one contractor has solved that problem by “not dealing with them anymore.”

“Our policy is that a rooftop unit needs preventive maintenance a minimum of four times a year,” says Joe Gennari, senior vice president, Industrial Building Services (IBS), Fort Lauderdale, FL.

Gennari has found that most customers don’t take maintenance seriously, so his company no longer takes customers who do not have a service contract with IBS.

Three years after adopting this “get-tough” policy, IBS’ reactive services calls are down from 50% to 20%. Gennari says his technicians are thrilled, because they can now work an acceptable number of hours each week without too many middle-of-the-night emergencies. And there is rarely any reason for anyone to put in an 80-hr-week backbreaker in the summer. In fact, Gennari says IBS is one of the few companies out there that actually has a waiting list of technicians wanting to become employees.

Since proactive service calls make up such a large part of the business, all IBS technicians are trained extensively on preventive maintenance of rooftop units. For example, the technician looks for something different on each of the four-times-a-year service calls.

The first time he might check the heating components, looking for cracked heat exchangers and checking burners, pilots, and heating controls. On the second visit he might cover the air conditioning cycle, checking the refrigerant charge, temperature drops across the coil, and making sure there’s proper airflow.

Of course, on all visits he’ll change the filter and check belts, bearings, and amperages.

Routine inspections are part of IBS’ preventive maintenance program. “We have a 22-point checklist the technician must complete when they inspect a rooftop unit,” says Gennari. Technicians have to write down which components are acceptable, what needs to be fixed in the next 6 months, and what should be fixed immediately.

Abuse through neglect

Unfortunately, most rooftop units don’t receive the same tender loving care. Gennari says many contractors aren’t taking the time to educate customers about the importance of proper maintenance.

“It’s amazing how someone will drive their car 3,000 miles and change their oil, and they’ll run their air conditioner 500 hours and won’t even change the filter.”

The industry may also be at fault for the way it views those who perform routine maintenance. “Our industry looks down on people who change filters, grease bearings, check pulleys, check amperages. Technicians in our industry are thought to be worth more if they can solve a big problem. But they should be worth more if they keep the problem from happening in the first place,” says Gennari.

Then there’s the whole issue of how preventive maintenance can benefit owners. A properly maintained rooftop unit can save an owner several thousand dollars a year in energy and operating costs. That more than pays for the cost of a service contract.

In fact, Gennari says that if a service contract doesn’t save an owner money, the preventive maintenance isn’t being performed correctly.

Nuts and bolts

When a rooftop unit isn’t operating correctly, Gennari says the number-one problem usually involves airflow, meaning belt or blower problems, or restrictions in the ductwork (including plugged filters or a plugged coil).

The next-most common problem usually involves the electrical system, such as bad fuses, thermostat, or contactors.

The third-most common problem usually involves the refrigeration cycle (leaks, the compressor, or metering device).

“The nice part about a rooftop unit is that it’s usually all right there for you, as compared to split systems that are located in different parts of the building. The simplest repair you’ll ever have in the hvac industry is probably on a rooftop,” says Gennari.

But how easy the repair will be often depends on the type of rooftop unit. Gennari notes that some manufacturers have definitely listened to their customers and put together contractor-friendly equipment.

“Units like the Lennox L Series were definitely made for mechanics. The blowers pull out on them, and they have a controller that tells you what the problem is — it gives you a code. You don’t even have to take your instruments out.”

Other units are not as easy to service. Some manufacturers have placed motors, terminals, and controls in such difficult places that you’d have to practically be a contortionist to service them.

Gennari says that difficulty in servicing can lead to other problems. “I can’t tell you how many roof leaks happen because someone takes off a 15-lb panel from a rooftop unit and drops it into a hot tar roof down here in Florida, when it’s 120¿F on the roof. Or, someone drops the screws and steps on them, and they go right through the tar. You definitely want rooftop units with panels on hinges with door handles.”

These are simple things, says Gennari. The technology doesn’t vary that much from manufacturer to manufacturer. But the nice touches made to a rooftop unit can make all the difference to a hot, tired contractor or technician baking in the summer sun.