The ABCs of Proper HVAC System Maintenance
Advice from an expert on keeping your school bus HVAC system running cozy.

Some HVAC system best practices include applying regular preventive maintenance and being intentional about making repairs.
Photo: Trans/Air/School Bus Fleet
The comfort and safety of students on school buses is of the utmost importance, and a well-maintained HVAC system is a key component in achieving this goal. Proper temperature control not only keeps students comfortable, but it also helps prevent distractions and keeps them alert on their way to school. In addition, HVAC systems help maintain proper air quality, reducing the risk of the transmission of germs and illnesses.
A professionally maintained HVAC system can also save money for school districts and their transportation operations.
School Bus Fleet shares advice from a seasoned HVAC technician, as well as a look at some of the latest HVAC offerings for school buses.
Apply Regular Preventive Maintenance
In the same way that a school bus engine needs to have regular preventive maintenance performed to continue operating, HVAC systems also need continuous attention.
A dirty cabin air filter is the root cause of many HVAC system issues, Shae Harkleroad of Pennsylvania-based Raystown Transit says. Performing a simple inspection of the filter can make all the difference.
“When [the cabin air filter] becomes plugged up, the whole efficiency of the system goes down. It makes the compressor run more, it makes it run harder, and it makes the condenser hotter,” Harkleroad explains. “If it's not changed regularly, that starts the downfall of the whole system right there. You can have the best temperature controls and humidity controls. But if you have a dirty air filter and it's not allowing the air to flow freely, you're going to start seeing other issues creep up.”
When changing out the filters, it’s important not to forget the filter in the chassis air conditioning system in the driver compartment on the bus. While the filter in the main compartments of the bus is typically easy to change, the one in the chassis system can be more time-consuming because it’s behind a panel. Be sure to remember to perform regular maintenance on that system as well.
Another part of the system that’s important to maintain: the condenser. Make sure to keep it clean and ensure that the fans are working. Additionally, make sure the belt that drives the compressor on the engine is in good condition. And lastly, maintain the proper A/C charge in the refrigerant system.
“A robust preventive maintenance program that includes monitoring operation, addressing any unusual noises, checking belts, and refrigerant ‘sight-glass’ for a dry and tight system is critical,” Trans/Air Manufacturing President Rick Lehnert says.
Be Intentional About Making Repairs

Photo: Canva
With all that school bus technicians have on their plate, it can be easy to put HVAC system maintenance on ice. And when the system goes out, it’s also easy for the technicians to simply ask the driver to open the windows on the bus, seeing a properly operating system as a luxury, Harkleroad says. But ignoring issues as they arise on the system will only lead to more problems. The same is true for avoiding regular cabin air filter changes. As mentioned earlier, a dirty filter can lead to more issues on the HVAC system, which can lead to a higher repair cost or a shorter life for the system.
In states where colder temperatures are more common, school buses are less likely to have A/C systems installed. However, heating systems typically come standard on school buses. It’s just as important to maintain the heating systems as it is the A/C systems.
Consider Training Opportunities
While it’s important to make these repairs, it isn’t always easy if technicians aren’t familiar with the system. Working on HVAC systems requires a bit of specialty knowledge. While putting time and resources into training opportunities for your staff may be costly up front, it can end up saving your department money, helping you avoid outsourcing the work.
Reach out to your HVAC system provider to see what training opportunities or resources may be available for your technicians. Giving technicians a chance to do hands-on training can help them familiarize themselves with the system as well.
Don't Overlook the Benefits
No matter what approach you take to maintaining HVAC systems for your school bus fleet, make sure you have a plan in place to keep them running well.
“In my opinion, climate control is an important safety component of the school bus,” Lehnert says. “Maintaining a comfortable and quieter environment for the driver improves their concentration and satisfaction.”
As driver shortages roll on, Lehnert believes driver comfort can significantly improve their satisfaction, so school districts and contractors can retain their drivers. Additionally, having properly working systems can also have an impact on students.
“The students’ behavior is better without windows open, or riding in a bus that is too hot or too cold, especially with students riding on the bus longer.”

Photo: Webasto/Canva

Photo: Trans/Air/Canva
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