Why Is My AC Cooling Unevenly?

Uneven Cooling Is Common with Aging Air Conditioners and Damaged Ductwork

Do you have a room in your home that feels like a walk-in fridge while another seems like a sauna, no matter how low you set the thermostat? Uneven cooling is a common issue for many homeowners. It not only makes your home uncomfortable, but it can signal a deeper problem with your system.

Before you start closing vents or cranking the AC, let’s break down the common causes of uneven cooling and how to fix it.

Common Causes of Uneven Cooling

1. Blocked Vents

One of the simplest reasons for uneven cooling is blocked vents. If certain rooms in your home feel warmer than others, start by checking to see if any vents are covered by furniture, rugs, curtains, or other household items.

Fix: Make sure all supply and return vents are clear and unobstructed so air can flow freely throughout your home.

2. Blocked or Leaky Ductwork

Your ductwork is like a highway for cool air. If there’s a traffic jam caused by a buildup of dust or a disconnected duct, air can’t reach certain areas. This causes some rooms, especially those located farthest from your HVAC system, to stay warm while others get all the cool airflow.

Fix: Have an HVAC pro inspect the ducts. Sealing any leaks and removing debris can restore even airflow to ensure every room in your home is cool and comfy!

3. Poor Insulation or Drafty Windows

Sometimes the issue isn’t with your AC, but with the home itself. Rooms with poor insulation or lots of sun exposure lose cool air faster than others, especially in older homes.

Fix: Check for drafty windows, unsealed doors, or lack of insulation in the attic or walls. A few DIY weatherproofing fixes or window coverings can go a long way. Hiring a professional to install more insulation, especially in the attic where cool air can easily escape, can lower your energy costs and create more even temperatures.

4. Improperly Sized AC Unit

If your system is too small, it may struggle to reach all parts of your home. Meanwhile, a system that’s too large may cool the space too quickly without running long enough to circulate air evenly.

Fix: A licensed HVAC technician can perform a load calculation to see if your system is sized correctly for your home’s layout and square footage.

5. Dirty Air Filters or Coils

When filters get clogged or coils get dirty, airflow slows down. That means some rooms may get less air than they should, especially those farther from the air handler.

Fix: Replace filters regularly (every 1-3 months), and schedule seasonal AC maintenance to clean the coils and check for blockages.

6. Old Air Conditioning System

Uneven cooling can sometimes be the result of an aging air conditioner that no longer performs like it used to. As systems get older, they can lose efficiency and struggle to cool your entire home evenly, especially rooms that are farther from the main unit.

Fix: Consider replacing your AC with a newer, more energy-efficient model. Most air conditioners last around 15 years, but they can wear out sooner if they haven’t been properly maintained or have been working overtime in extreme conditions, which is common if you live in Florida, Arizona, or other regions with year-round warmth.

When It’s Time to Replace Your AC

In some cases, when you’re experiencing problems with your air conditioner, including uneven cooling, it’s a sign that it might be nearing the end of its lifespan. If your AC is more than 12-15 years old and uneven cooling is becoming the norm despite regular maintenance, a replacement might be the most cost-effective fix.

Other signs replacement might be needed:

• Frequent repairs
• Rising energy bills
• Inconsistent temperatures even after repairs

Upgrading to a modern system with variable-speed technology or multi-stage cooling can dramatically improve comfort and efficiency. These systems adjust their output based on demand, so your home stays cooler and more balanced – even during peak summer heat.

Don’t Skip Regular AC Maintenance

Think of HVAC maintenance like brushing your teeth. It’s not glamorous, but if you skip it, you’re going to have problems down the road. A basic tune-up every spring helps catch small issues before they turn into big, costly ones, and it keeps your system running smoothly and evenly.

During a routine maintenance visit, a technician will inspect and clean your coils, change the air filter, check refrigerant levels, tighten electrical connections, and test overall system performance. These simple checks can extend the life of your system, improve energy efficiency, and help prevent uneven cooling in your home.