Does Closing Air Vents Help Cool Other Rooms?

You might have heard that closing air vents in unused rooms can save you money on cooling costs. Moreover, people claim that closing air vents, especially in unused rooms, helps cool other rooms. Is this a reality, or is it one of the many HVAC system misconceptions?

Closing air vents doesn’t help cool other rooms. When you close air vents, air backs up in the ductwork and puts stress on the blower. This can damage your HVAC system and make it work less efficiently, which will end up costing you more in repairs and utility bills.

In the rest of this article, I’ll explain why closing air vents doesn’t help cool other rooms. I’ll also discuss the risks of closing air vents in your home. Let’s get started!

Why Closing Air Vents Doesn’t Cool Other Rooms?

Heating, Ventilation, and Air Conditioning (HVAC) systems contribute significantly to home energy consumption. An HVAC system accounts for 70 percent of landlord consumption. For this reason, you may consider closing air vents in unused rooms to help cool air in other rooms without using much of the HVAC system.

However, I’m here to debunk this misconception by explaining what happens when you close some air vents.

Air vents allow the free flow of conditioned air to and from your HVAC system. These vents provide access points to the ducts running through your home.

When you close one or more vents, the air has nowhere to go but back into the ductwork. As a result, the blower has to work harder to move air through the system, which can lead to leaks.

In some cases, closing vents can cause the condensed water to build up in your HVAC system’s coils, which can lead to mold growth, a severe health hazard.

While closing air vents doesn’t cool other rooms, and can’t help you save on your cooling costs, there are other options that can help.

Some of these options include:

  • Investing in energy-efficient windows or insulation.
  • Upgrading to a more energy-efficient HVAC system.
  • Adding a whole-house fan.
  • Installing a programmable thermostat.

Read: Why Dust Coming Out Of Air Vents?

What Happens if I Close Air Vents in My Home?

According to the EPA, HVAC systems are essential for maintaining healthy indoor air quality. Apart from cooling and heating the air, these systems have air filters that trap dust, pollen, and other airborne contaminants.

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If you close air vents in your home, the air filters won’t be able to do their job correctly, leading to poor indoor air quality due to insufficient airflow. In some cases, this can also cause respiratory problems.

It’s also worth noting that your home’s furnace has a minimum return airflow volume that aids sustain a safe temperature. When you close supply air vents, the return airflow decreases, which can cause the furnace to overheat and shut down.

The worst consequence of reduced airflow due to closed supply air vents is overheating the heat exchanger, the most expensive part of the system, that costs $1,500 on average. So, if you’re thinking of closing air vents to save money, think again!

Read: Can An Attic Be Used To Vent A Portable Air Conditioner?

How To Manage Airflow in the Vents?

Now that you know closing your air vents is catastrophic, how can you manage airflow through the vents?

The best way to manage airflow through the air vents is by closing them partially. It’s suitable to close the vents 50 to 74 percent of the way. This is an excellent way to keep air flowing through the system while saving energy.

It’s essential to know the air vents you can close partially and the ones that should always remain open. You can partially close all other vents in your home apart from the ones in the basement.

Basements are critical areas exposed to challenges like excessive moisture. Therefore, air vents in this location play a significant climate control role. Closing these air vents can expose the basement to issues like mold growth.

Another way to manage airflow is by using a “zone damper.” A zone damper is an automated device that controls airflow in your ductwork. This way, you can direct conditioned air to specific areas of your home without affecting other rooms.

Read: How To Fix Ecobee Thermostat AC Blowing Cold Air Through Intake Vent?

Consequences of Closing Air Vents

The last thing you can do for your home’s HVAC system is fully close the air vents. Closing these vents leads to the following:

Higher Energy Consumption

Closing air vents increases the static pressure in the HVAC system. High static pressure forces a significant volume of heated or cooled air into the unconditioned zones of the home through leaks. Consequently, the house loses the conditioned heating or cooling air.

The furnace is forced to run longer to compensate for the lost heating or cooling. The result is increased energy consumption, leading to higher utility bills.

Leakages in the Ductwork

Ductwork leaks are the last thing you want in your HVAC system. Leaks not only reduce the efficiency of your system but can also lead to health hazards.

The increased static pressure from closed air vents expands the ductwork to create more space. As the pressure builds up, the ductwork reaches its elastic limit, forcing it to rupture and release the tension. This is how leaks form in the ductwork.

Some signs of leakages in an HVAC system ductwork include:

  • An unexpected spike in heating or cooling bills
  • The furnace runs continuously
  • Mold growth
  • Unusual noises in the ductwork

Read: How Strong Should Air Come Out Of Vents?

Possible Mold Growth

The surface temperature in the unused rooms is lowered when you close the air vents. Low surface temperature in a room creates the ideal atmosphere for condensation.

Condensation increases the relative humidity in a room, making it an ideal place for mold. Mold thrives in a humid environment and can cause health problems like headaches, skin irritation, and respiratory problems.

Molds are especially dangerous for people with allergies or asthma. They can trigger an asthma attack or worsen the symptoms.

Carbon Monoxide Exposure

Carbon monoxide is no joke, and should be taken very seriously. It’s very hard to detect, as it’s:

  • Odorless
  • Tasteless
  • Colorless
  • Poisonous

Due to the reduced airflow, the furnace works extra hard when you close the air vents. The consequence is cracking the system’s heat exchanger.

A cracked heat exchanger exposes your family to carbon monoxide. This gas is dangerous because it can cause serious health problems like headaches, dizziness, and nausea. In high concentrations, carbon monoxide can be fatal.

Detecting carbon monoxide can be hard due to its odorless and tasteless nature. Therefore, investing in a carbon monoxide detector is the best way to keep your family safe from this gas. The detector will alert you when there’s an unusual concentration of carbon monoxide in the air.

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02/05/2023 08:30 pm GMT

Ductwork Repair and Replacement

The increased static pressure in the HVAC system caused by closing vents can cause irreparable damage to the ductwork. In most cases, you’ll have no choice but to replace the entire system, which is a significant investment.

A poorly designed and installed HVAC system is more likely to develop problems when you close the vents. This is because such systems can’t handle the increased static pressure.

The best way to avoid issues with your HVAC system is by having a professional design and install it. A good quality system will last for many years without any problems.

Read: How Is Indoor Air Quality Measured?

The Bottom Line

You should never close air vents in your home as this doesn’t cool other rooms. Furthermore, doing so has dire consequences that leads to increased energy consumption, leakages in the ductwork, and mold growth.

You should invest in proper insulation and sealing of the ductwork if you want to save money on your utility bills and improve your HVAC system’s efficiency. This will ensure that conditioned air doesn’t escape and unconditioned air doesn’t enter your home.