Why Does the AC Take So Long to Cool Down the House?

When it’s hot outside, you count on your cooling to keep things comfortable inside. But is your AC taking a long time to cool down the house? This is typical on sweltering days, which squeeze your AC system harder than normal. However, if it’s not very hot outside and your cooling is still struggling, your cooling equipment may have a problem. Try these tips to help you troubleshoot the matter. 

Dirty Air Filter 

A clogged filter is the most frequent reason an AC system takes too long to cool the house. The job of a filter is to catch airborne contaminants that could harm delicate HVAC equipment. More advanced filters even capture tiny airborne contaminants to increase indoor air quality

As time passes, the filter becomes clogged with dust, pet hair, and textile fibers, reducing circulation. Besides making your AC unit take more time to cool down the house, this issue can also lead to larger energy bills, additional wear and tear, and overheating. 

Solution: Check your air filter each month and replace it if it looks dirty. Try not to wait more than three months to change the filter or follow the manufacturer’s recommendations. If you’re not sure where an air filter can be found, ask your HVAC technician at your next service visit. 

Improper Thermostat Settings 

Your thermostat must be compatible with your air conditioner to run effectively. Then, you have to set it correctly to sustain a cozy temperature. Implementing a programmable or Wi-Fi thermostat offers the best results. 

Solution: If you want to update your thermostat, require help learning about programmable features, or aren’t comfortable programming a thermostat on your own, contact an HVAC technician at Service Experts Heating, Air Conditioning & Plumbing for support. 

Dirty Evaporator Coil 

Split-system air conditioners have an indoor unit and an outdoor unit. The indoor unit features the evaporator coil, which soaks up heat from the air via the refrigerant. It’s hard for the refrigerant to absorb heat effectively if the evaporator coil is dirty, making it take more time to cool your house. 

Solution: Contact our HVAC specialists to clean and tune up your air conditioner. An element of this call includes cleaning out dirt and grime from the evaporator coil to enhance cooling performance. 

Dirty or Obstructed Outdoor Unit 

A cooling cycle will require moving hot refrigerant to the outdoor unit, where it exhausts heat into the outdoor air. That said, if the outdoor unit is dirty or covered with encroaching yard waste, the cooling cycle could be less effective. 

Solution: Lightly hose off the outdoor unit to get rid of dust, cobwebs, pine needles and grass clippings. Then, prune back bushes to around 12 inches from the unit to enhance airflow. 

Refrigerant Leak 

Refrigerant is the secret to effective cooling. Typically, this substance moves in a closed loop between the indoor and outdoor units. If a leak occurs and your AC loses refrigerant, it becomes less capable of absorbing and expelling heat from your home. 

Solution: Only a licensed technician can correct refrigerant leaks and replenish the system. If you think you’re dealing with this problem, call our HVAC professionals for help straight away. 

Leaky Ductwork 

Air ducts are vital to your HVAC system. A leak in either the return or supply side can make your air conditioner run harder and longer to keep your home cool. 

Solution: If you experience inconsistent temperatures and high amounts of dust around the house, get in touch with Service Experts Heating, Air Conditioning & Plumbing to examine your ductwork. Duct sealing or replacement can take care of the problem. 

Dirty or Blocked Air Vents 

Cool air can only circulate throughout your home as long as the vents are open and free from any obstructions. Closing too many vents can even throw off the system’s balance, contributing to additional breakdowns and repair costs. 

Solution: Take a look at the vents in every room, seeing to it that they’re open and not blocked by furniture, rugs or window treatments. 

Old or Inadequately Sized AC System 

Did you install your cooling more than 10 to 15 years ago? As it gets older, the unit becomes less efficient and may fail to maintain comfortable temperatures. Furthermore, have you recently completed a home extension or made other modifications? This could result in an undersized air conditioner that can’t keep up with demand. 

Solution: The only solution for an aging or undersized air conditioner is to exchange it. Count on our trained HVAC technicians to size and install your new unit for comfort and efficiency. 

Schedule AC Repair with Service Experts Heating, Air Conditioning & Plumbing 

If your troubleshooting still proves ineffective, it’s time to contact the HVAC pros at Service Experts Heating, Air Conditioning & Plumbing. We supply fast, effective service to get your AC back up and running as soon as possible. Rest assured that our technicians adhere to the highest standards of customer service to ensure your long-term satisfaction. Contact us to schedule air conditioning repair or additional HVAC services today. 

Savings For You

See All Offers Here >


  • Save $50 on a Paid Service
  • Written 100% Satisfaction Guarantee
  • Plus, ask how to save an additional 15% and waive your trip charge!


  • Upgrade to Worry-Free Comfort with the Advantage Program and make NO payments for 30 days!

© 2024 Service Experts, Service Experts Heating & Air Conditioning, and the Service Experts logo and design are registered trademarks of Service Experts LLC and used under license by SE Canada Inc. All Rights Reserved. *Not applicable to the Advantage Program. See your signed Advantage Program Agreement for full details and exclusions. 100% Satisfaction Guarantee is subject to certain restrictions and limitations as set forth in the applicable Terms and Conditions.

Chat with a Service Experts Professional