Does Closing Doors Help Air Conditioning?

In the dog days of summer, you want to do anything you can to keep your home cool and your AC running efficiently. Many people think that closing interior doors in a home will help their AC system run better, but that’s actually not the case—in fact, you’re probably doing the opposite. 

Below, we break down why closing doors can sabotage your chances at a cool and comfortable home and offer some tips on how to actually boost your air conditioner's performance.

Should You Close Doors in Unused Rooms?

People who recommend closing doors in unused rooms typically believe that this keeps the cool air in and takes the pressure off the AC unit. But when you keep a bedroom door closed, the air becomes trapped inside that room, raising the air pressure. The air tries to escape around the tiny cracks under the door or in the ceiling vents, so it leaks into areas you weren't trying to cool.

Air conditioning systems are designed to cool the whole home, so disrupting that process with closed doors actually worsens the performance of these finely-tuned machines.

When a room is shut off from the rest of the house, a “negative pressure” builds that sucks air into the room from other areas of the house, or even outside. This raises the temperature of the room and prevents the AC from working properly.

Shutting off interior rooms from the air conditioning in the rest of the house will also worsen the air quality in those rooms. You’re actually disrupting the ventilation of a home, which makes it difficult to move fresh air freely throughout the structure.

So if you don’t want to walk into a room that feels hot and stuffy, you should always leave interior doors open whenever possible. Keeping interior doors open will both improve the energy usage of your air conditioning unit and improve the comfort level in the whole house.

How You Can Increase AC Performance

If you're still determined to lower your air conditioning costs and improve AC performance, there are some things that can actually help.

1. Improve Insulation and Caulking

By adding insulation to your home and getting better caulking around the trim of rooms, you ensure that air isn't leaking. Your home should be like a thermos, meaning it holds its temperature steady by preventing cool air from escaping and warm air from getting inside. These materials keep the temperature where it’s supposed to be.

2. Keep Shades Drawn

The hot summer sun beaming through your windows can quickly heat up your rooms, which must work extra hard to keep the space cool. Draw your curtains and shades to keep rooms cooler and give your AC unit a helping hand.

3. Turn on Your Fans

Fans improve air circulation, which means your air conditioning system doesn't have to work as hard getting air flowing. Fans take very little energy, so there's virtually no downside to running them.

4. Change or Clean Your Filter 

You should change your AC or furnace filter every 30 days. It’ll help regulate the temperature during those balmy summer months. Clean, fresh filters also improve both air quality and efficiency. 

5. Keep Doors and Vents Open

Especially with central air, closed doors and vents only obstruct the blower fan and ventilation, which leads to balmy, hot air. Closing a door unbalances the system, causing pressure changes and air leaks. Open vents and doorways help keep air flowing and your home cool. 

6. Clean Your Vents

One of the best ways to boost the efficiency of your air conditioner is to keep the vents free from debris like pet hair and dust. Clean vents equal stead airflow so grab your vacuum and get to cleaning. 

7. Replace Old Thermostats

Newer thermostats offer better performance than the older models that lack programming features. Programmable thermostats let your HVAC system run more efficiently by reducing heating and cooling output when people are asleep or away, which translates to increased energy savings.

Check Your Air Conditioning System’s Performance

Rather than trying to think of tricks to increase the performance of your air conditioning system, a better method to keep energy usage at a minimum is to have a professional check and maintain the system regularly. A poorly functioning AC won’t be able to cool your home properly  and can also cause your energy bill to skyrocket.

Many companies that service HVAC systems will offer low-cost or free inspections to new customers. Contact a local HVAC pro near you for help.