Why Is My AC Not Sending Enough Cool Air Through The Vents?

If your HVAC system is blocked up or clogged somewhere, your AC won’t send enough cool air through the vents when it’s running. A fan problem can also cause this issue. Or, you can end up with that problem if you don’t address the circulation issues.

It’s not always easy to realize a circulation problem in the summer. As long as the system’s running, it can take a while before you notice it’s not working as well as it used to.

The common signs include the temperature staying higher than your thermostat setting. And more humidity inside than usual.

That’s usually when people start running their hands over the vents to see if they’re getting any cool air.

In this article, we’ll address the most common reasons why you suddenly don’t have enough cool air coming through your vents. However, we’re not covering what to look for if you’ve always had this problem.

If your home has always had weak airflow, it’s likely the sign of bad or inadequate ductwork. It’s pretty common, especially in Boise.

Many of the older homes in the city were around before forced-air HVAC came around. So, it’s not always easy to retrofit ductwork that does the job.

If you’ve always noticed weak airflow in an older home, we suggest reading up in ductless mini splits as an alternative to forced-air heat. But, if this is a new problem, keep reading. And, call us at Snowflake Air for AC repair at (208) 205-9078 if you can’t fix it yourself.

We’ll help you troubleshoot each one and let you know when it’s time to call a professional to repair a broken air conditioner.

Wrong Thermostat Settings

The wrong thermostat setting can prevent your system from turning on. Or, it will turn on but not do what you want it to. It’s common to forget to switch something after the winter. Or maybe someone else fiddled with it. Either way, this is the best place to start troubleshooting.

How To Fix It

Change the batteries if it’s been a while because low power can cause a thermostat to malfunction. Next, make sure it’s set to “Cool” and not “Heat” or “Fan Only.”

The “Fan Only” setting circulates air without warming or cooling it. So, you’d notice air coming through the vents, but it’s not cool.

And, if you’re curious, the U.S. Department of Energy says you can save money while still keeping cool if you keep your thermostat at 78 degrees most of the time in the summer. 

Clogged Air Filter

When the air filter in your HVAC system becomes clogged with dirt and dust, it won’t allow any air to pass through. That’s why you need to replace it every so often. It’s supposed to trap all that stuff, so it doesn’t gum up your system or keep circulating through the house. 

But, if you leave it too long, it restricts airflow as well. You may also end up with some warm air flowing your vents instead of cool. Or the AC turns off and on again every few minutes.

How To Fix It

Put a new air filter in your system every month when running the AC or heater. Do the same every three months when it’s not running. 

If the cloth screen is gray or darker when you take it out, you left it in too long. It should still be primarily white. Otherwise, it’s clogged. 

Closed Or Blocked Vents

Each vent in your home should be open and clear all the time. Otherwise, you won’t get the cooling you want. Most vents have a latch to close them, but you shouldn’t bother with it.

The only time to close a vent is if you’re cleaning and don’t want anything spreading through the house. Or if you’re not using the system and you’re getting cold air in the fall. But, it’s tough to see when it’s closed, so it’s easy to forget about opening it again.

How To Fix It

Confirm your vent is open by pushing the latch up. And, each one should have a square foot of open space around it. That’s the best way to ensure the air can circulate properly.

Broken Furnace Fan

The fan in your furnace is responsible for pushing the air through the system and back out to your home. If it’s broken or malfunctioning, you’ll notice weak airflow.

In this case, air is still coming into the system and cooling. But, the fan isn’t strong enough to push it through the ductwork. You’ll get very little coming through the vents.

A broken fan furnace can cause this problem, but it can also happen as a result of it: When there’s a blockage preventing airflow, your fan has to work harder and harder to do the job. That causes it to wear out.

How To Fix It

This one’s a job for a professional to diagnose and fix. We don’t recommend taking apart your furnace and replacing pieces. At best, you’ll void a warranty. At worst, you’ll hurt yourself.

If you’ve gone through these other troubleshooting steps and still have the problem, call your HVAC contractor. And, remember to call right away: Fixing a small problem before it gets worse could save you the cost of a brand-new AC system. 

How To Prevent Low Airflow Problems With Your Air Conditioner

Preventive maintenance, or an annual tune-up, is an excellent way to prevent low airflow problems with your AC. It also heads off many other problems and keeps your home comfortable all summer. 

A tune-up usually takes about an hour. In that time, your HVAC tech checks dozens of inspection points throughout your HVAC system. They’ll clean out everything, optimize all the moving parts, and replace anything worn out or broken. 

This way, you know your AC system is in great shape for the warm summer ahead.