If you’re looking for a low-cost way to combat energy waste, HVAC preventive maintenance should be at the top of your list. When your HVAC equipment is running clean, balanced, and calibrated, it runs much closer to rated efficiency specifications. And when your HVAC system runs more efficiently, you benefit from lower runtime, reduced kW demand, and lower monthly utility bills.
Dirty filters, leaky ducts, failing motors, and refrigerant problems are common sources of energy loss before they even impact comfort. You can save energy and lower utility costs just by performing routine HVAC maintenance.
Here’s how:
HVAC equipment includes the following components and accessories:
• Thermostat and controls.
• Air handler/furnace including blower motor.
• Evaporator coil.
• Outdoor condenser/compressor unit.
• Refrigerant lines and TXV or other expansion device.
• Filters and ductwork.
The average residential system is sized somewhere between 1.5 and 5 tons of cooling capacity (18,000 to 60,000 BTU/h). A system that cools and heats a 1,500–2,000 sq ft home is typically around 3 tons or 36,000 BTU.
The largest consumers of energy in HVAC systems are as follows:
• Runtime of compressor.
• Power draw of the blower motor.
• Efficiency of airflow.
• Condition of ductwork.
Think of your cooling system like a water faucet. The fewer restrictions there are to cooled airflow, the less time it takes to reach your thermostat’s setpoint temperature. When heat exchanger efficiency or airflow is reduced, the compressor must run longer to meet demand. The longer your compressor runs, the more money you pay each month on your electric bill.
Energy Loss Factors
Regular HVAC service addresses each of these areas to reduce runtime:
Dirty Air Filters – Can quickly reduce HVAC airflow by 5–15%
Dirty Evaporator Coil or Condenser Coil – Up to 20% heat-transfer inefficiency
Duct Leakage – Leaky ductwork loses up to 30% of air in many homes
Low Refrigerant Charge – Low charge decreases system capacity and runtime
Capacitor Failure / Motors Draw Extra Amps – Boosts power consumption when failing
This may mean simply cleaning air conditioner coils, vacuuming out ducts, sealing leaks, flushing drains, or changing filters.
Every efficiency detractor forces your HVAC equipment to operate longer than necessary to achieve your desired comfort level.
HVAC Preventive Maintenance Tasks That Save Energy
- Changing HVAC Filters
Air filters should be checked every month and replaced as needed. Most require replacement every 1-3 months. Restricted airflow causes the fan to work harder. The harder the fan works, the more static pressure builds inside your ductwork and HVAC equipment.
When your air filter is dirty, your HVAC system can lose 5-10% of its airflow instantly.
Energy Savings: Restores proper airflow. Often sees immediate efficiency improvements of 5-10%.
- Cleaning HVAC Coils
Condenser and evaporator coils heat exchange indoor air with refrigerant. Dirty coils have insulation (dirt) built up on them that inhibits heat transfer.
If coils are dirty, the system efficiency will decrease by roughly 10-20%.
Energy Savings: Improves heat transfer and reduces compressor runtime.
- Checking Refrigerant Levels
Undercharged systems struggle to pull heat out of your home or put heat into your home. Each HVAC system is charged to a certain specification. Too much or too little refrigerant reduces efficiency.
Low refrigerant causes longer runtimes and puts stress on the compressor.
Energy Savings: Reduce likelihood of running continuously, saving you money and extending compressor life.
- Sealing Ducts and Balancing Airflow
Did you know homes can lose up to 30% of their airflow through leaky ductwork? Leakage typically happens where ductwork transitions through attics and crawl spaces. Cleaning and sealing ducts adds quiet to conditioned airflow.
The ideal airflow through your home is approximately 400 CFM per ton of cooling capacity. When ducts are sealed and airflow is balanced through the home, the system will reach desired temperatures quickly. Additionally, rooms will stay comfortable longer and won’t require the system to run as long overall.
Energy Savings: Improves comfort and lowers HVAC run times.
Replace your air filter regularly to improve efficiency.
- Calibrating Thermostats
For every degree you adjust your thermostat, you’ll see approximately a 1% change in energy usage.
By setting back your thermostat 7-10 degrees for 8 hours a day, you can save about 10% annually on HVAC energy costs.
Energy Savings: Proper calibration can reduce overcooling and runtime.
Lower Energy Bills = Less Money Spending on Repairs
Components don’t fail overnight. They degrade over time.
A failing component will draw more energy than its replacement. For example:
• A weak capacitor may increase an electrical motor’s amp draw.
• As blower motors fail, they restrict airflow.
• Dirty burners won’t combust as well, decreasing furnace efficiency.
While it may cost you $150 to replace that capacitor today, waiting for the compressor to fail could cost you $2,000. Not only will energy use increase when equipment fails, but efficient components use less electricity and run as designed.
Longer HVAC Lifespan = Lesser Need for New Equipment
If maintained properly, you could add 3-5 extra years of life to your HVAC system.
An efficient system that lasts the expected 15 years could fail after year 10 without proper maintenance. Wear and tear on electrical connections, refrigerant leaks, and metal fatigue can reduce the lifespan of any HVAC system.
You can avoid paying $6,000 to $12,000 for a new HVAC system by spending $200 to $400 a year in preventative maintenance costs. Preventive maintenance can help lower your total cost of ownership by extending the years you can go between equipment upgrades.
Bonus DIY Tips to Save Energy
In addition to annual maintenance, there are a few simple things you can do in between professional HVAC maintenance to lower your energy bills.
• Change your air filter.
• Ensure 2 feet of clearance around outside units.
• Vacuum supply and return air vents.
• Flush your condensate drain monthly with vinegar.
• Check your thermostat settings each season.
Take care of the small things so they don’t turn into big problems during your service visit.
What Does Professional Maintenance Include?
Professional HVAC tune-ups should include:
• Verification of refrigerant pressures.
• Cleaning of coils.
• Measuring static pressure.
• Testing of temperature split.
• Tightening of all electrical connections.
• Verification of blower motor amp draw.
• Calibrating thermostat.
• Checking ductwork for leaks or restrictions.
Yearly maintenance reports should include all test results so you can keep yearly tabs on efficiency.
We’ve seen customers save hundreds on their utility bills simply by ensuring airflow and heat transfer were restored to peak condition. By identifying and fixing larger problems, our maintenance techs can sometimes improve efficiency by up to 20%.
Here’s a Real Example
Let’s say you have a 3-ton HVAC system that pulls 3.5 kW of power at full load.
After maintenance, let’s assume efficiency improved by 10%. That translates to a savings of 0.35 kW while the system is running.
If your system runs for 300 hours during a cooling season, that equals 105 kWh of savings. At $0.15 per kWh, you would save just over $15 each season for each HVAC unit you have.
This can add up over several years, as we’ve seen many customers save this much or more just by ensuring their system is running clean and balanced.
Reducing Energy Usage Starts with HVAC Maintenance
Now that you know how HVAC preventive maintenance saves energy, think about how it can help you. Maintenance reduces your energy bill by:
• Restoring proper airflow.
• Cleaning and improving heat transfer efficiency.
• Reducing runtime on HVAC equipment.
• Helping to prevent breakdowns caused by worn parts.
• Extending the overall life of your HVAC system.
Maintenance allows your HVAC system to run as it’s supposed to instead of slowly becoming inefficient over time. Your system runs more efficiently, which puts more predictable comfort in your home while lowering your monthly energy costs.
FAQ
Q1: How often should I schedule HVAC maintenance?
A: We recommend maintenance be performed twice annually for most systems, spring and fall, but you should also check your air filters every 1–3 months.
Q2: HVAC Maintenance saves how much energy?
A: Reducing your energy bill by 8-15% is not unheard of once we correct airflow restrictions and dirty coils.
Q3: Is HVAC maintenance really worth it?
A: Definitely. Most homeowners spend far less on maintenance than they would on repairs and inefficiencies.
Q4: Will maintenance prevent costly breakdowns?
A: Regular maintenance can prevent many catastrophic failures by catching worn electrical components, refrigerant leaks, and dirty coils early.
Q5: Does maintenance even help my older HVAC system?
A: Yes! Even older HVAC systems can regain noticeable efficiency improvements by simply cleaning and calibrating the system. However, if your system has poor efficiency compared to newer products, replacement may still be a better option.