In case you, like me, may be wondering where the summer went, here’s your reminder that we’re more than halfway through August. And by this point, your commercial AC system has been putting in some serious hours. The good news? If your building is cool, comfortable, and running without a fuss, that’s a great sign.
But mid-season is also a smart time to take a closer look.
You don’t need to wait for a unit to quit on the hottest day of the year to find out something is wrong. A quick mid-summer check can uncover all the little culprits of slow performance decline in commercial AC units. These little buggers (like dirty coils, restricted airflow, drainage problems, and worn components) are likely to turn into expensive service calls later.
Think of this as a mid-season HVAC checkup, not a full replacement for professional maintenance. Your maintenance team should handle electrical testing, refrigerant measurements, and other work that requires specialized tools and training. But there are several things facility managers and building maintenance teams can keep an eye on between service visits.
First, here’s an overview of a standard RTU (rooftop unit) to clarify what we’re talking about.
Here’s a practical mid-summer commercial AC checklist.
1. Take a Walk Around Your Commercial AC Equipment
Start with the simple stuff. Walk around your rooftop units, condensers, and other outdoor equipment. Look for:
- Debris, weeds, nests, or other obstructions around the equipment
- Loose or damaged panels
- Visible rust or corrosion
- Signs of water around the unit
- Anything that looks noticeably different from your normal equipment condition
Your outdoor equipment needs adequate clearance to move air effectively. If weeds, boxes, garbage or other objects have started creeping into the equipment area, now is a good time to clear them out.
The original SyncQuip pre-season checklist recommends checking the surrounding area for hazards, inspecting for visible damage and corrosion, and ensuring a proper ventilation around the unit.
Mid-season tip: Don’t just look at the equipment. Look at the equipment compared with how it looked earlier in the summer. Changes can be more telling than a single snapshot.
2. Check Filters
This one is easy to overlook once the cooling season gets rolling.
Filters collect dust, dirt, pollen, and other airborne debris as the system runs. As they become loaded, airflow can suffer and the system may have to work harder to move conditioned air through the building.
Check filters regularly and replace them according to your facility’s requirements and the manufacturers recommendations, unless this is included in your maintenance contract.
And don’t assume that because you changed them at the beginning of summer, you’re good till fall. Depending on the building, occupancy, outside air needs, and operating conditions, they may need attention sooner.
3. Pay Attention to Airflow
Walk through the building and actually notice how the spaces feel.
Are some areas warmer than they were earlier in the summer? Are certain rooms struggling to maintain temperature? Are supply vents producing noticeably weaker airflow? Are employees complaining about hot or stuffy areas?
Uneven temperatures can have multiple causes, including airflow problems, dirty components, damper issues, controls problems, or changes within the building.
The pre-season checklist specifically calls for checking the blower assembly, belts and electronic dampers for proper operation. If you have any known issues with these in the past, it may be worth checking them again now. Not comfortable with that level of checking? Get an HVAC technician to check them for you, especially if you’re experiencing issues.
If comfort complaints are becoming more frequent, don’t automatically assume the thermostat is the problem. Your HVAC system is a team sport. Sometimes the thermostat gets blamed for things it didn’t do.
4. Look at the Condensate Drain
Your commercial AC unit is pulling moisture out of the air every time it cools the building. That moisture has to go somewhere.
Check around the condensate drain pan and drain line for:
- Standing water
- Overflowing or wet areas
- Visible algae or buildup
- Slow drainage
- Water where it shouldn’t be
A clogged condensate drain can eventually cause water damage or shut down equipment, depending on the system.
To locate your condensate drain, start at the indoor air handling unit (AHU) or the rooftop unit (RTU). You should be able to trace the rigid PVC or copper pipe as it runs to a floor drain, utility sink, exterior wall or outdoor drainage system.
If you see water where it shouldn’t be, don’t ignore it. A small drainage problem can become a much larger problem surprisingly quickly.
5. Give the Coils a Look
Dirty coils make your HVAC system work harder.
Outdoor condenser coils are particularly vulnerable to dirt, cottonwood, grass clippings, dust and other debris during the summer. Indoor evaporator coils can also accumulate dirt when airflow or filtration isn’t where it should be.
Look for visible buildup and make sure the condensers has ample clearance for airflow.
Coil cleaning is one of those jobs where it’s important to know what you’re doing. Commercial equipment can be damaged by improper cleaning methods, so when the coils need mor than a basic visual inspection, it’s worth having a trained HVAC technician handle it.
6. Listen to Your Equipment
You know what your equipment normally sounds like. That makes your ears one of your most useful diagnostic tools. Listen for:
- New rattling
- Grinding
- Squealing
- Excessive vibration
- Repeated clicking
- Unusual humming
- Sounds that weren’t there earlier in the season
A new sound doesn’t necessarily mean disaster is imminent. But it does mean something has changed, and that’s worth investigating before the equipment decides to make its next announcement at 2:00 pm on the hottest day of August.
7. Watch for Refrigeration Problems
Refrigerant issues aren’t something your maintenance team should try to diagnose by guessing at pressures or adding refrigerant without proper testing. Instead, notice the symptoms when they start.
If the system is:
- Struggling to maintain temperature
- Running for unusually long periods
- Producing less cooling than normal
- Developing unusual frost or ice
- Showing signs of a possible refrigerant leak
…it’s time to get a qualified commercial AC technician involved.
The pre-season checklist includes checking several technician-level things like refrigerant levels and leaks as well as verifying proper operation of expansion valve or metering device. The idea behind that is to note and preempt anything that might go wrong during peak season. So if you have a regular maintenance plan, these things shouldn’t become a major issue mid-season, but it’s worth being aware of the symptoms.
8. Check the Thermostat Controls
Your building may be comfortable, but that doesn’t necessarily mean your controls are working exactly as they should. Check that:
- Thermostats are displaying normally
- Setpoints haven’t been changed unexpectedly (those office elves!)
- Occupied and unoccupied schedules are correct
- Zones are responding appropriately
- Building automation alarms aren’t being ignored
If your building has multiple zones, pay particular attention to areas behaving differently from the rest of the building.
A controls issue can sometimes look exactly like an HVAC equipment problem. That’s why testing thermostat operation and calibration is part of the standard inspection process.
9. Notice How Long Your Equipment is Running
Here’s a simple question worth asking: Is your equipment running more than it used to?
Some long run times are completely normal during extreme heat. But if a unit seems to be running constantly while struggling to reach its setpoint, it’s worth investigating.
Keep an eye out for equipment that runs continuously, cycles unusually often, struggles to reach setpoint, or has noticeably different performance than neighboring units.
Don’t wait for a complete failure to investigate a change in performance. Mid-season is actually an excellent time to address these issues because you still have time to make repairs before the next heat wave turns a minor problem into an emergency.
10. Look at Your Maintenance Records
This might be the least exciting item on the list, but it can be one of the most useful. Pull up the service and maintenance records for your major HVAC equipment. Look for:
- Repairs made earlier this year
- Components that were noted as showing wear
- Recurring problems or repeat repairs
- Recommended repairs that haven’t been completed
- Equipment that has been operating outside normal readings
- Upcoming maintenance requirements
Your HVAC system has a history. Good maintenance records help you see the story instead of treating every service call like a brand-new mystery.
A Mid-Summer HVAC Checkup Can Save You From a Mid-Summer Emergency
Like a mid-life crisis, the idea is to avoid crisis by being aware and in tune with your needs and circumstances. The goal really isn’t to find something wrong with every piece of equipment. Quite the opposite!
A good mid-season check is about confirming that your HVAC systems are continuing to perform the way they should and catching small changes before they become expensive interruptions.
And if you do find something questionable, that’s where your HVAC service team comes in. Electrical connections, capacitors, motors, refrigerant pressures, controls, belts, and other mechanical components require the right tools, training, and safety procedures. Your job is t be the first to notice a small change and keep your eyes and ears on it for development. Call when something doesn’t look right.
That’s a whole lot better strategy than waiting for a rooftop unit to wave a white flag.
The Bottom Line
Your commercial HVAC equipment has already done a lot of work this summer. Now is a good time to make sure it isn’t quietly struggling behind the scenes.
A few minutes spent checking the obvious — filters, airflow, equipment condition, drainage, controls, and overall performance — can help your maintenance team spot problems early. And if you’re already seeing warning signs, don’t wait for the system to make the decision for you.
Keep your equipment maintained! Keep and eye on changing performance. And give your HVAC team a chance to fix problems while they’re still problems, rather than when they become emergencies.
That’s really what good commercial HVAC maintenance is all about: fewer surprises, better equipment performance, and keeping your building comfortable without making HVAC the most exciting thing happening at your facility.
Looking For a Commercial HVAC Maintenance Partner?
Having a trustworthy partner in commercial AC maintenance mid-summer is something that eases most of the anxiety about HVAC. You don’t have to worry about identifying and troubleshooting the parts of your RTU. Let us do that. Get in touch today for a maintenance quote. Drop us a note below, or call 402.733.1747.