Role Of Cold Air Returns In The Heating Process? (Find Out Now)

Ryan Womeldorf
by Ryan Womeldorf

Your furnace is a fairly complicated piece of equipment. While the heating process may seem relatively straightforward, there are actually many components that go into it all. Understanding what each of them does can be the key to troubleshooting issues down the line.

One thing that may seem a bit confusing is the role of the cold air returns in the heating process. Basically, the cold air returns allow the furnace to “breathe in” the air from your home. When the warm air gets pushed into the room, the cold air is then pushed out of the room through the cold air returns.

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What Does the Cold Air Return Do?

In essence, your HVAC system “breathes” in air and “exhales” it into your home. The imperative thing here is that airflow is balanced. So, the amount of air that gets “breathed” in must be equal to the amount that goes out.

The purpose of the cold air return allows the furnace to take air in. Those cold air registers are close to the ground all around your home. The reason is that they take in the air that sinks down towards the floor.

Whenever warm air gets pushed into a room, the cold air that is already there gets sucked out through the cold air returns. When the air is in the returns, it moves through the ductwork and back into the furnace. Once there, it gets filtered, heated, and then sent back into your home to warm it.

What is the Best Way to Maximize the Performance of Cold Air Returns?

When it comes to the cold air returns, you want them to work optimally so that your home’s airflow is balanced. So, it only makes sense that you would do whatever necessary to ensure that the cold air returns are doing their job.

1. Don’t block them

This might seem a bit obvious, but cold air returns can get blocked in a number of ways. For proper airflow around your house, make sure that there is nothing blocking or obstructing your cold air returns.

If you have any furniture or household items nearby that could be blocking the registers, move them. They can prevent proper airflow and keep the cold air returns from properly doing their jobs.

2. Add more returns

Some older homes didn’t come with enough cold air returns, limiting airflow. You may notice some rooms are stuffier, there is uneven heating, unbalanced pressure, and even higher energy bills.

Should you suspect that there aren’t enough cold air returns, contact your local HVAC company. They can provide an in-home inspection. This way, you can know with certainty whether there are enough cold air returns and if they are doing their jobs.

3. Keep them clean

One of the best ways to ensure that your cold air returns are doing their job is to keep them clean. Even if there is no furniture blocking them, a buildup of dust and debris can do the same thing.

Pop open the vent covers and ensure that both the registers and the openings are clean and clear. If you suspect that there may be heavy dust and debris buildup deeper into the system, call a certified HVAC technician to come take a deeper look.

Why You Should Adjust Your Registers

If you haven’t adjusted any of your registers, it isn’t too late to start. All it takes is a few minutes each season and it is well worth the effort. There are quite a few benefits to adjusting the return registers in your home.

  • Energy costs. When your registers are doing their job efficiently, they can help save you serious money on heating and cooling over time. You will pay less to air condition or heat your home when proper airflow is coursing through the home.
  • Long-term efficiency. When you make adjusting the registers a habit, you set up a long-term system for saving money. More importantly, you ensure that the registers are operating at an efficient level going forward. Again, all it takes is a quick adjustment each summer and winter.
  • Keeps you aware. If you make the habit of adjusting the registers each summer and winter, it makes your system more efficient. But if you notice a change in that efficiency, it can alert you to other potential problems within the HVAC system. Those problems can fly under the radar, but when you are adjusting the registers, you may notice the signs a bit earlier.

It Is Important to Adjust the Registers for Winter

A good thing to remember is that cold air falls and hot air rises. When the temperatures begin to drop, you want that cold air to get drawn out through your cold air registers. That should leave nothing but the hot air behind.

Opening your lower cold air registers and closing the higher up ones can keep that hot air in as the cold air gets drawn out. Cold air is also heavier than warm air, so it should automatically make its way down into the lower return registers in your home.

How Do You Adjust Returns for Summer?

Similarly, you want the hot air to get drawn out in the summer while the cold air remains. Since cold air is heavier and drops to the floor, it only makes sense to close the registers that are closer to the floor.

Open the higher registers to draw out the hot air (heat rises, remember). This should help your system keep the warm air out while keeping the cool air in.

Does Every Room Need a Cold Air Return?

Remember, there can be a problem with airflow throughout the home if there are not enough cold air returns. Unless you are paying attention to the airflow in your home, it can be difficult to know if there are enough cold air registers.

Generally speaking, it is a good idea to have them in each room. Additionally, there should be returns that are located at the bottom and top of the walls for the aforementioned reasons. Make sure that they are on an exterior wall, preferably near a door or window.

How Do I Know If My Air Return is Working?

An easy way to identify the return vents is by turning on the system’s fan. With the fan running, put a piece of paper or your hand up to one of the vents. Should you feel a suction effect or the paper gets pulled towards it, you have a return vent.

There are also supply vents. While the return vents pull out the type of air that you don’t want, the supply vent does the opposite. It provides the kind of air that you want. So, if you are looking to cool your home, the return vent pulls out the warm air while the supply vent pushes in cold air.

A Few Things to Know About Return Vents

There are a couple of misconceptions about the return vents in your home. We have covered a few things in the above sections, but there are three things in particular that many homeowners do not realize.

  • Return vents control air pressure. When your home’s HVAC system blows air into the home, it results in a pressure change inside the house. That excess air has to go somewhere, so the return vent acts as a welcome spot for the air. Generally speaking, return vents are larger than supply vents because the air handler needs the larger space to suck all that air into the system.
  • Don’t assume your home has enough. To those who aren’t familiar with HVAC systems, you may assume that you have all the returns that you need. Unfortunately, that may not be the case. Homes that were built prior to central air tend to have retrofitted systems.

Those retrofitted systems tend not to be the most efficient systems in the world. And because they aren’t super-efficient, they may not come with the proper number of vents. Having one vent in each room is a good rule of thumb. Having a couple is better as it creates a better, more consistent air pressure within each room.

  • You can clean them yourself. Cleaning the returns is relatively simple, too. All you need to do is pull off the metal grate and give it a good wash once in a while. Whenever you change out your air filters, suck up any debris that falls off or near your vents. You can even use a damp cloth to get any excess dirt and debris near the returns, too.

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Related Questions

Why is my bedroom so cold?

Should you notice a cold room or two in your home, the most likely cause is dirty vents. It can also be due to worn insulation or even cracked ductwork. There are do-it-yourself fixes possible, but the best course of action is to bring out an HVAC technician to troubleshoot the issue. If you don’t have a lot of experience, it can be quicker and cheaper to just bring in a professional to look for the problem.

Ryan Womeldorf
Ryan Womeldorf

Ryan Womeldorf has more than a decade of experience writing. He loves to blog about construction, plumbing, and other home topics. Ryan also loves hockey and a lifelong Buffalo sports fan.

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