With energy prices continually increasing, it’s practical to look for ways to cut your cooling costs over the summer. It may be recommended to you by family and friends that you close vents in rooms that you don’t use very often in hopes of forcing more cool air into other areas. This isn’t an ideal situation. Read on to find out more about how household air circulation works, including five reasons why you should not close your vents. We’ll also talk about other options that help you achieve a comfortable home and decrease energy consumption without creating problems within your HVAC system.

Basics of Household Air Circulation

Your home must have adequate air circulation to move cooler air away from the supply vents and into the rest of the room. Let’s start by looking at how your HVAC system circulates air and how closing vents affects this process.

Your system includes supply vents where chilled air comes out. There are also return vents that are part of this system. This is where warm air goes in. Your supply vents create positive air pressure when air comes from them. Conversely, your return vents create negative pressure when they draw air in.

The principles of fluid dynamics state that pressure in a closed container must equalize. By creating negative pressure in one area and positive pressure in another area, you create a mechanism that forces the air to move. This is what causes the cool air coming from your air conditioner to move throughout your home rather than just stay near the supply vents.

The number and location of your supply vents, along with the number, size, and location of your return vents, allow the system to create adequate circulation. When you start closing vents, you interrupt the process by limiting the positive pressure your system is creating. While this may not seem like a big deal, it has several impacts on your home, your air conditioning, and your entire HVAC system.

1. Raises Your Energy Costs

As you close vents around your home, your air conditioner’s ability to move cool air throughout these spaces decreases. If your thermostat is installed correctly, it’s mounted on an interior wall that isn’t directly in line with a vent. If your home isn’t circulating the cool air properly, the air won’t reach that thermostat when it should. The end result is longer cooling cycles while the system tries to make the thermostat achieve the set temperature.

The longer the system runs, the more energy the unit consumes. Instead of helping reduce your energy costs by forcing more air into the areas that need it, closing vents can actually cause your energy bills to climb.

2. Adds Strain to Your System

Strain is a significant concern for your AC and HVAC systems because it not only increases how much energy is consumed each hour but also adds wear to the entire system. Simply running longer cycles causes added strain on the system.

Closing enough ducts can also cause the coils to freeze, which adds strain to the compressor. The compressor is sensitive to this excessive strain and can burn out when it can’t circulate the refrigerant properly. Once you have a damaged compressor, you’re likely looking at either substantial repairs or a system replacement.

Closing ducts can strain your system’s circulating fan by creating too much resistance and increasing the pressure within the ducts. This can cause damage to the circulating fan motor, causing it to also burn out.

3. Uneven Cooling

The idea behind closing vents is to force more air where the house stays warmer while diverting it from areas that don’t necessarily need it. However, what you often end up with is uneven cooling throughout your home, despite your best intentions.

As you close the vents, the cool air comes out of your supply vents and may move a little bit. However, it will take much longer to distribute throughout your space. You’re unlikely to get it distributed evenly throughout your house. What you’ll experience is even greater temperature variation throughout your house, leaving you struggling to get comfortable during those hot summer months.

4. Damage to Your Ducts

The circulating fan in your HVAC system creates pressure in your ducts to force air through to the end of the system. Depending on where you close vents in the system, this can create excess pressure within the ducts beyond what it was designed to handle.

This can cause your ducts to make more noise than normal. This may also cause damage to your ducts, creating leaks at the joints if they aren’t properly sealed. Once the ducts have leaks, both your AC and heating efficiency drop substantially because the conditioned air leaks out rather than arriving where it should.

Leaks in your ducts create an opportunity for unfiltered air to enter the system. The contaminants in the air then settle throughout your system, including inside your ducts. This further reduces the system’s efficiency, degrades your home’s air quality, and causes even more strain on your HVAC system.

5. Encourages Mold Growth

No one wants to think about mold growing in their ducts. When your AC and HVAC systems are working properly, there’s little to be concerned about. This is because the normal airflow through the vents helps keep moisture levels regulated.

When you start closing vents, you reduce airflow through parts of the ducts because you create a block in the system. The area is already dark, and with humidity levels rising in the summer, moisture may quickly accumulate. This creates the perfect environment where mold can thrive. You may notice this as an issue if you start having a musty smell while your AC is running, or if you experience an increase in allergies or upper respiratory illnesses during the summer months.

Consider Zoning Your System

There is a safe alternative to closing vents in unused areas of your home.
This alternative is known as zoning your HVAC system.

When you have an automatically managed zoned system, your home is split into different areas. Each is managed with its own thermostat. You can set the temperature in each zone so that areas you use infrequently aren’t kept at the same temperature as the rest of the house.

Each zone has the proper number of supply and return vents to circulate air throughout the zone. When a particular zone doesn’t need conditioned air, the dampers in the ductwork will close. This directs the conditioned air to the zones that are calling for it. The only caveat is that you have to modify your ductwork and have a compatible system to run the zones.

Another system that naturally creates zones is the ductless mini-split system. Rather than running ducts, each zone has its own air handler, usually installed on an exterior wall. All of the air handlers then run to a single heat pump compressor outside, making them an incredibly efficient system option.

People throughout Rome and Floyd County have depended on Hitchcock Heating & Air to keep their homes comfortable and safe since 1987. Our team takes pride in providing trusted heating and air conditioning maintenance, repair, and installation, together with indoor air quality solutions. We also offer smart home equipment installations. Call to schedule a consultation with one of our zoning experts to discuss whether a zoned HVAC system is right for your home.

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