Most commercial buildings rely on equipment that most people never actually see. Up on the roof, your RTU HVAC system is working through heat waves, cold snaps, wind, dust, and everything in between. When it’s running well, no one thinks about it, but when it’s not, everyone notices.
Since rooftop units are out of sight, it’s easy for small problems to go unchecked and eventually turn into uncomfortable tenants or expensive repairs. Let’s break down RTU HVAC basics, covering common trouble spots, early warning signs to look for during walkthroughs, and simple preventive maintenance tips that can help you avoid any unexpected downtime.
What Is an RTU HVAC System?
A rooftop unit (RTU) is a self-contained system installed on the roof of a commercial building. You can find these rooftop units on anything from warehouses and retail centers to schools and offices. They typically house all the major components in one cabinet, including the compressor, condenser coil, evaporator coil, supply and return fans, filters, and heating section (whether that be gas or electric).
With everything packaged together, RTU HVAC systems offer a practical and scalable solution for commercial properties. Like any piece of equipment, however, they need consistent attention to stay reliable, especially because they handle so much in one place.
Five Common RTU HVAC Issues to Look For
While rooftop units are built to withstand a lot, they’re not immune to wear and tear. Here are some of the more common issues we see building owners and facility managers run into.
1. Dirty Filters
As filters collect dust and debris, airflow becomes restricted. When that happens, the system has to work harder to push air through your building. Over time, that extra strain can have a serious impact, reducing efficiency, driving up energy costs, and even leading to frozen coils or unnecessary wear on major components. It’s a simple maintenance task to keep up with that can make a big difference long-term.
What to watch for:
- Weak airflow from vents
- Rooms that feel stuffy
- Tenants or employees complaining about uneven temperatures
2. Dirty or Damaged Coils
Coils are responsible for transferring heat. However, when they’re coated in dirt or debris, or starting to corrode, the system will start to lose efficiency fast. The result? Longer run times and more strain on the compressor, which is one of the most expensive components in any RTU HVAC system. The best way to protect your system’s health and performance is to ensure coils are cleaned regularly.
What to watch for:
- Cooling that never quite catches up
- Ice forming on the unit
- Sudden spikes in energy use
3. Electrical and Control Issues
RTU HVAC systems rely on things like sensors, relays, contactors, and control boards in order to operate smoothly. Over time, these electrical connections can loosen or just fail altogether. Scheduling routine inspections is essential in ensuring any electrical issue that may crop up is addressed early.
What to watch for:
- The unit won’t turn on
- Frequent short cycles (constantly turning on and off)
- The breakers are repeatedly tripping
4. Drainage Problems and Water Leaks
Air conditioning naturally creates condensation. If your drain lines clog or the pans crack, that water has nowhere to go and will be forced back into the unit or leak into the building. When left unchecked, that moisture can damage your RTU HVAC system, the building itself, and have a negative impact on your indoor air quality.
What to watch for:
- Water stains on the ceiling tiles
- Musty odors
- Standing water in or around the unit
5. Fan and Belt Wear
Fans are responsible for moving conditioned air throughout your building, so when they’re not operating properly, it can affect comfort fairly quickly. When your unit is under constant demand, it can cause belts to loosen, crack, or slip, and bearings or motors to struggle to keep up. This can decrease airflow and put added strain on your entire RTU HVAC system, so it’s important to catch these issues early to prevent any unexpected shutdowns.
What to watch for:
- Squealing, grinding, or rattling noises
- Noticeable vibration during operation
- Reduced or inconsistent airflow
What to Look for During Routine Walkthroughs
You don’t have to be on the roof every week to spot trouble. In many cases, RTU HVAC issues show up inside the building first. During walkthroughs, keep an eye out for:
- Hot or cold spots
- Increased humidity
- Unusual smells
- Thermostats that don’t seem responsive
- Rising energy bills
If multiple tenants are raising similar concerns, it’s often a sign that the rooftop equipment needs to be looked at. When you do check the roof, you’ll want to look for:
- Loose or damaged panels
- Debris around the unit
- Rust or visible corrosion
- Unusual operating noises
Simple Preventive Maintenance Tips
Preventive maintenance is not only your best friend, but it’s the most effective way to protect your RTU HVAC investment. Here are a few essential items that should be on your checklist:
- Replace your filters on a regular schedule
- Clean and inspect coils
- Check electrical connections and controls
- Inspect belts, motors, and bearings
- Clear and test the condensate drain line
We suggest having your RTU HVAC system inspected at least twice a year before the cooling and heating seasons ramp up. If your building is one with high demand, you might want to consider scheduling a quarterly service. Preventive maintenance is such an important part of caring for your equipment. Not only does it extend the life of your system, but it can also help control your operating costs and lower your chances of needing emergency repairs.
Staying Ahead of RTU HVAC Problems
Rooftop units don’t usually just fail overnight. You can expect to see some warning signs first. The key is knowing what to look for and acting before small issues turn into big disruptions. A little proactive attention to your RTU HVAC system can mean fewer surprises, better energy performance, and more comfortable tenants year-round.
If you’d like a second set of eyes on your rooftop equipment or want to build a reliable maintenance plan, partnering with the Silver State team can help you stay ahead of breakdowns and keep your building running smoothly. Contact us today to learn more.
