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

When it’s sizzling outside, you depend on your AC system to keep things cool inside. But is your air conditioner taking forever to cool down the house? This is common on sweltering days, which strain your cooling harder than usual. However, if it’s not especially hot outside and your AC is still having a tough time, your air conditioner could have a problem. Use these tips to help you diagnose the problem. 

Dirty Air Filter 

A clogged filter is the most frequent reason an air conditioner needs more time to cool down the house. The job of a filter is to snare airborne pollutants that can harm your HVAC equipment. More effective filters even capture microscopic airborne allergens to improve indoor air quality

Over time, the filter becomes stuffed with dust, pet hair, and textile fibers, limiting the flow of air. Besides making an air conditioning system take longer to cool down the house, this situation can also produce larger energy bills, higher wear and tear, and overheating. 

Solution: Check your air filter each month and replace it if it looks dirty. Don’t wait past three months to change the filter or follow the manufacturer’s recommendations. If you’re not sure where your air filter is, talk to a local HVAC technician at your next service appointment. 

Improper Thermostat Settings 

Your thermostat must be compatible with your cooling to run effectively. Then, you must set it correctly to maintain a comfortable temperature. Using a programmable or Wi-Fi thermostat produces the best results. 

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

Dirty Evaporator Coil 

Split-system air conditioners come with an indoor unit and an outdoor unit. The indoor unit houses the evaporator coil, which soaks up heat from the air using refrigerant. It’s challenging for the refrigerant to absorb heat effectively if the evaporator coil is filthy, making it take longer to cool your house. 

Solution: Get in touch with our HVAC specialists to clean and tune up your air conditioner. An important part of this call involves removing debris and grime from the evaporator coil to improve cooling efficiency. 

Dirty or Obstructed Outdoor Unit 

A cooling cycle will require transporting heated refrigerant to the outdoor unit, where it ventilates heat away from your home. However, if the outdoor unit is dirty or surrounded by encroaching yard waste, the cooling cycle may be less successful. 

Solution: Gently hose off the outdoor unit to eliminate dust, cobwebs, pine needles and grass clippings. Then, trim back bushes to around 12 inches from the unit to enhance airflow. 

Refrigerant Leak 

Refrigerant is vital to air conditioning. Normally, this substance moves in a closed loop among the indoor and outdoor units. If a leak occurs and your air conditioner loses refrigerant, it becomes more difficult to handle the cycle of absorbing and expelling heat from your home. 

Solution: Only a trained technician can fix refrigerant leaks and replenish the system. If you suspect this problem, call up our HVAC experts for help at once. 

Leaky Ductwork 

Air ducts are the arteries and veins of your HVAC system. A leak on either the return or supply side could make your air conditioner work harder and longer to cool your home. 

Solution: If you notice uneven temperatures and excessive 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 around your home when the air vents are open and free from any obstructions. Shutting too many vents can even disrupt the system’s balance, resulting in increased breakdowns and repair costs. 

Solution: Take a look at the vents in every room, ensuring they’re open and unblocked by furniture, carpets or curtains. 

Old or Undersized AC System 

Did you set up your air conditioning more than 10 to 15 years ago? As it ages, the AC becomes less effective and might be unable to maintain comfortable temperatures. Furthermore, have you recently finished a home extension or made other changes? This can result in an undersized air conditioner that won’t always keep up with demand. 

Solution: The only solution for an old or undersized air conditioner is to exchange it. Trust our licensed 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, feel free to bring in the HVAC professionals at Service Experts Heating, Air Conditioning & Plumbing. We deliver fast, effective services to get your cooling 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 request air conditioning repair or other 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.