End-of-Summer HVAC Maintenance Tips

The summer cooling season puts more stress on commercial HVAC equipment than any other time of year. By the time Labor Day passes, HVAC systems have been running at or near full capacity for months. And that wear accumulates in the worst way possible. Fall is the perfect time to identify and handle issues before the winter heating demand creates emergency conditions.

The stakes are real for your HVAC systems and budget. U.S. commercial and industrial facilities absorb approximately $50 billion annually in unplanned downtime costs, and research consistently shows that 95% of HVAC failures are preventable through regular preventive maintenance. Every dollar invested in preventive care returns an estimated $4 to $6 in avoided repairs and energy savings. The opposite is equally true. Facilities that skip end-of-season maintenance pay for it, one way or another.

Let’s take a look at what a thorough end-of-summer HVAC transition looks like in practice.

1. Inspect the Exterior HVAC Unit

Start with a complete walkthrough of your outdoor equipment. After a full summer of operation, debris accumulates quickly and airflow restrictions compound efficiency losses.

• Clear the area: Remove leaves, dirt, and any other obstructions that are within two to three feet of each unit. Fall brings leaf accumulation fast. Regular checks can help you stay on top of the pile-ups.

• Clean condenser coils: Dirty condenser coils are a leading cause of efficiency loss in commercial systems. The Department of Energy found that a moderately dirty coil increases electricity use by 39% on a 3-ton unit and 47% on a 5-ton system. Those numbers should make coil cleaning one of the highest-ROI tasks on this list

• Check for physical damage: Inspect cabinets, fins, and connections for cracks, dents, corrosion, or loose components. It’s important to address any findings before they become winter failures

• Trim vegetation: Cut back bushes and shrubs to maintain proper clearance and airflow around all units

2. Address Refrigerant the Right Way

The original version of this post recommended verifying refrigerant levels as a routine seasonal task. That framing needs an update. Under current EPA Section 608 regulations, refrigerant should not be checked as a standard maintenance item unless there is a suspected leak or documented performance issue. Any refrigerant work must be performed by an EPA-certified technician. Facility managers should monitor system performance indicators: if cooling capacity has dropped, the system runs longer than normal, or ice forms on coils, those are signals to call a certified technician for a proper diagnosis.

3. Clean Indoor HVAC Coils and Clear Drain Lines

The end of summer is the right time to address evaporator coil condition and condensate drainage before transitioning to heating mode.

• Clean evaporator coils: Dirt and debris on indoor coils can restrict airflow and reduce heat-transfer efficiency. Just a dirty condenser coil alone can increase your energy consumption by 30%

• Clear condensate drain lines: Clogged drain lines cause costly, completely avoidable failures. That includes water damage and system shutdowns. A clogged condensate drain that could be cleared for less than $50 in routine maintenance can trigger thousands of dollars in emergency repairs if left unaddressed

4. Optimize HVAC System Performance

• Replace air filters: The end of summer is a great time to change your HVAC’s filter. You could use a MERV 8 filter for standard commercial spaces or a MERV 13 filter for healthcare/food service environments. High-traffic or dusty facilities usually need more frequent changes throughout the year

• Calibrate thermostats and controls: Miscalibrated thermostats can cost you in energy and maintenance. They can cause inefficient cycling and uneven climate control in your buildings. Fall is the time to review and update cooling setpoints, economizer changeover temperatures, and night setback schedules for the heating season

• Inspect economizer dampers: Stuck damper actuators basically cause your system to run as 100% recirculation. That eliminates free cooling and ventilation compliance. You should cycle each damper through its full range of motion and document the results

• Balance airflow: Check for proper airflow distribution throughout your HVAC system. Hot and cold spots often signal duct leakage or damper issues. Duct leakage alone wastes 15 to 30% of conditioned air before it reaches occupied spaces

5. Complete Mechanical and Electrical Checks

• Lubricate moving parts: Apply the right lubricant to your system’s blower motors, fan bearings, and other moving components. Check belt tension on fan drives. Belts can often stretch under low-load summer conditions. That stretching can then cause slipping and accelerated wear on startup

• Inspect electrical connections: Check for loose or corroded connections in your HVAC equipment. Tighten or replace them as needed. Electrical failures are among the most common causes of HVAC breakdowns

• Test heating systems: Run a brief functional test of the heating system now. Don't wait until outside temperatures make a heating failure an emergency. Identify issues while there is still time to schedule non-emergency repairs

6. Seal the Building Envelope

Lastly, no fall maintenance checklist for HVAC efficiency is complete without addressing your building’s shell. Have your maintenance staff check insulation levels, seal air leaks around doors, windows, ductwork penetrations, and pipe chases. These issues can reduce heating and cooling loads. Ultimately, a high-efficiency HVAC system operating in a leaky building will consistently underperform a modest system in a well-sealed one.

Go Further: Protect What You've Already Cleaned

End-of-summer maintenance restores your system to baseline. Protective coatings from 

Energy Performance Solutions can help keep it there longer.

CoilSafe forms a thin, covalently bonded, glass-like coating on HVACR coils that protects against corrosion that silently erodes heat-transfer capacity between maintenance intervals. It's UV-stable and self-cleaning, so coils stay cleaner longer. That reduces both the frequency and intensity of future cleaning cycles. CoilSafe is validated through 6,000+ hours of ASTM B117 salt fog testing.

ThermalBlock is applied to HVAC cabinets, ductwork, and rooftop surfaces. It reflects 89% of visible light and rejects 87% of external heat gain, reducing the solar heat load absorbed by rooftop equipment and translating directly to lower energy consumption during the next cooling season.

Together, these coatings extend the service life of equipment you've invested time and money in maintaining—protecting that investment through the seasons ahead.

Have questions about your HVAC systems or want to learn more about CoilSafe and ThermalBlock? Call our experts at 713-931-2735 or visit energyps.com.

Citation List

1. OxMaint, "HVAC Preventive Maintenance Checklist (2026): Reduce Downtime & Energy Costs" (February 2026). oxmaint.com

2. OxMaint, "Seasonal HVAC Maintenance Checklist: Spring, Summer, Fall & Winter Guide" (March 2026). oxmaint.com

3. OxMaint, "HVAC Maintenance Checklist: Seasonal PM Guide for Facilities" (March 2026). oxmaint.com

4. OxMaint, "HVAC Maintenance Cost Breakdown for Commercial Buildings" (March 2026). oxmaint.com

5. OxMaint, "HVAC Maintenance Cost Breakdown" (February 2026). oxmaint.com

6. Facilities Dive, "The 5 most common commercial HVAC failures — and how to stop them" (November 2025). facilitiesdive.com

7. Recoil HVAC, "How Corrosion Impacts Commercial HVAC Systems (And How to Prevent It)" (February 2026). recoilhvac.com

8. Sensibo, "How to Reduce Costs of HVAC Systems for Commercial Buildings" (July 2026). sensibo.com

9. SolarTech Online, "Commercial Energy Efficiency Guide 2025: Strategies & Incentives" (May 2026). solartechonline.com

10. Summit Facility Solutions, "Summer Facility Management Guide 2026." summitfacilitysolutions.com

11. Home Comfort Solutions, "End of Summer HVAC Maintenance Checklist" (January 2026). thehomecomfortsolutions.com

12. Champion Industrial, "Creating a Fall HVAC Maintenance List" (February 2026). championindustrial.com

13. U.S. EPA, "Section 608 Regulations." epa.gov