Adjusting Cold Air Return Vents During the Fall Season (2023)

FAQs

Should cold air returns be open or closed in the winter? ›

Adjust Return Registers for Winter

Since cold air is heavy it will automatically flow down to the lower register, so keep your lower return vents open in the winter.

Close top return vents.

If you have a top/bottom return vent setup, close the top vents in the winter months. Closing the top vents will make your system draw in air from the bottom vents that are at the low point in the room where cold air settles.

In most houses, dampers on the upper level are opened in the summer and shut in the winter. In the winter, closing the dampers to the upstairs allows for heat to rise naturally as it is distributed throughout the home. In the summer, the lower level is naturally cooler, and most people report having hot rooms.

Down Low: if you have your air return lower on your wall it will function better as a cold air return. This will allow your air return to draw in cold air as it sinks to the bottom of the room. Making it more efficient at recirculating this cold air through your furnace to repeat the heating cycle.

In the heating cycle, blocked cold air returns can cause the heat exchanger inside the blower compartment to store too much heat and eventually crack. If the cracks are too large, the furnace can emit carbon monoxide into your home's air. Such a condition normally requires a complete system replacement.

Closing your upstairs vents greatly reduces the temperatures in those spaces, causing the temperature to drop throughout your home as the cold air from those spaces circulates to other areas of your home. Your HVAC system, to hit the higher temperature that you've set, will stay on longer.

The first thing most homeowners notice in the case of not enough return air are the hot and cold spots. Having some rooms that are hot and others that are cold is a tell-tale sign of not enough return air. Example: Let's say you have HVAC ductwork across your entire house.

During the summer, we don't need the added humidity in our homes, so the damper is closed to keep any additional moisture out. Now that we're entering the heating season, it's extremely important to remember to open humidifier dampers for the upcoming winter.

The fireplace damper should always be in the open position whenever you have a fire in the fireplace. Never close the damper or leave the fireplace unattended while there is a fire in the fireplace. This is not only a fire hazard, it can also cause deadly carbon monoxide poisoning.

How far should I open my damper? ›

Keep the damper open until all open flames are gone. When there are coals and embers still in the fireplace, close the damper to stop heat from escaping through the chimney. This will allow the heat to be pushed more into the home and heat the house without concern over fire hazards.

Leaving the damper open doesn't help hot indoor air escape up the chimney. Instead, outdoor air will flow down the chimney while the cool air from your air conditioner escapes. Your cooling system will work harder than it should, leading to an increase in energy bills and shortening the lifespan of your HVAC unit.

Instead, there should be at least one return vent in every room, with two or three being ideal. If your house has only one return vent, this is not a problem — make sure to keep the doors open in every room so the air can circulate properly. Make sure there are no furniture, draperies, rugs, etc.

If they are too small, airflow will be restricted and there will not be enough air circulation to heat or cool the inside of your home. Return air ducts must be sealed and unobstructed — Sealing return air ducts is just as important as sealing supply ducts.

Long story short: It's never a good idea to cover up cold air returns. Don't succumb to the temptation, and always check that air is circulating freely when you move furniture. If your HVAC system isn't performing the way you would like, it might have other efficiency issues.

Having several return vents (ideally one in every room, but even two or three is better than just one) creates consistent air pressure. If you have one return vent, your home is fine. Keep the doors to each room open so air can properly circulate.

An HVAC system with excess capacity can heat or cool your home faster, but that speed often results in a couple of other issues. First, your home won't benefit from gradual, even heating and cooling. As a result, you could end up with a number of hot or cold spots throughout your home.

When the AC filters are clogged with dirt, hair, dust, and other debris, the airflow through the vents in your home may be reduced, decreasing the efficiency of your air conditioning system. This can also happen if the AC filters are blocked by some furniture placed right in front of the system.

The short answer is no; you should not close air vents in your house. Closing vents can actually waste more energy than operating your system normally. How does closing air vents waste energy? Because when you close vents in unused rooms, your central air system will push the excess air to other places in your home.

How do you balance the heat in a two story house in the winter? ›

Set the first floor's thermostat to your desired temperature, and then decrease the temperature setting on your thermostats by two degrees as you go up. Warm air on the first floor will rise and make the upper floors more comfortable.

In the winter, set your thermostats up in the opposite direction. The thermostat on the lowest floor should be set the warmest and the top floor the lowest temperature. The lowest floor will reach your desired temperature, and warm air will rise to heat the upper floors.

Test Your System

Try this simple test when your HVAC system is running: get a piece of tissue paper and dangle it about six inches from one of the return vents. You should be able to see it being gently pulled towards the vent. Next, place it up against return vent and see if the air suction holds it in place.

When warm air is delivered to a room, the existing cold air in that room is pushed into the cold air and returns. Once inside your cold air returns, that air travels through your ductwork back to your furnace where it is filtered, heated, and sent back to warm your home.

The simplest way of bringing in fresh air through the HVAC involves a motorized damper and controller. When the damper is open, it delivers fresh air from the outside to the “return” side of the furnace so that the incoming air can be properly filtered and conditioned before being distributed with the recirculated air.

Bottom line: You probably shouldn't close your air supply vents. Excessive static pressure inside an HVAC system is never a good thing. Closing too many air supply dampers could put you in the static pressure "danger zone." Instead, have a pro measure the static pressure to see if you can safely adjust your dampers.

Most people find that they need to adjust the airflow when the weather turns from cold to hot air. To determine if your air conditioning vents need to be adjusted seasonally, you will just need to monitor the ambient air temperature in each room of your home for two or three days.

A damper should always be fully opened when starting a fire or adding wood to the stove, allowing the firebox to draw the most air. Closing the damper restricts the airflow, releasing exhaust smoke and heat.

A fireplace damper should always be kept open while the fire is burning. Furthermore, keep the damper open until all the embers are completely out; since smoke and dangerous carbon monoxide can enter the house. Once the ember bed is entirely out, close the damper.

You need to open the damper when you start a fire to allow for proper airflow and let the smoke out. A closed damper can restrict airflow and become a safety issue since smoke would fill your house.

How do I know if my damper is working? ›

Manual Control Damper

Flip the damper into an open position and inspect the registers once more to see if airflow begins. You probably have a bad damper if, when the damper is closed, you feel limited airflow or none at all.

This will prevent your heated or cooled air from escaping your home through the fireplace and chimney, as well as block drafts from outside. Hiring a professional chimney sweep company will help you ensure that you close the damper the right way.

One caution, though: Fireplaces with installed gas logs are required to have the damper open at all times. That's either because a pilot light is constantly burning under the logs or because the homeowner might forget to open the damper when he or she turns on the fire.

How Long Do HVAC Dampers Last? The quality of the equipment, how frequently you run your HVAC unit, and if you follow regular maintenance schedules can all affect the lifespan of your HVAC components. Dampers can last around 20 years with proper maintenance.

If you are in the far north, or in the Southern US, the answer is simple. In an air conditioning climate the return duct goes near the ceiling to draw off the hot air and cool it down. In a heating climate, the return duct goes near the floor to draw off the cold air and heat it up.

Having two air return vents allows you to seasonally control which air is returning to the HVAC system. In older homes, this may not be an option. The theory is that in the Summer cooling season, you want to be circulating warmer air back through the HVAC system to be cooled.

By setting your thermostat to no more than 20 degrees below the outside temperature, you can save on energy costs and help give your AC a break. The next time it's hot and muggy outside, appreciate that your AC is doing its best to keep you a comfortable 20 degrees cooler.

While it's best practice to install a thermostat near a return air vent, so that the thermostat senses a homogenous mixture of air sucked from various areas of the home, it's a mistake to have the thermostat located near a supply air vent, where hot or cold air blowing on it can change its reading.

When setting your thermostat, most homeowners find 72 is a good temperature for air conditioning. However, you may need to adjust that setting based on weather conditions. The bigger the difference between indoor and outdoor temperatures, the higher your energy bill will be.

Can You Have Too Much Return Air? Too much return air coming through your system isn't much of an issue because the fans and ductwork working to get that air back into the system only pull with so much force to make the HVAC system work correctly.

When should cold air return vents be open? ›

Hot air rises and cool air sinks. Therefore, opening the right return vents in the summer and winter significantly improves the distribution of air by your forced-air system. You'll also enjoy more even heating and cooling throughout your home. In the summer, open your high returns and close the low ones.

Return air ducts must be sealed and unobstructed — Sealing return air ducts is just as important as sealing supply ducts. Sealing all duct section connections with mastic, a specialized rubbery sealant, or with metal tape prevents air leaks.

It's a good practice to close off the vents in winter. Doing so prevents the dry, cold winter air from freezing the pipes inside the crawl space. Crawl space condensation. Many homes built on crawl space foundations experience condensation due to open vents and poor moisture management.

If the AC system is operating correctly, then the air coming out of your vent should be about twenty degrees cooler than the regular temperature inside. So, if you're cooling it and the house is 80 degrees, then you would ideally want the air to be about 60 degrees. Have more air conditioner questions?

Should Return Air Vents Be Open Or Closed In Winter? Once again, NEVER close a return air vent. If you have operable cold air SUPPLY vents in your home, you can close upper supply air vents and keep lower return air vents open in the winter to keep your home cozy while allowing your heating system to work efficiently.

What Happens When Return Vents Are Blocked? The system will have to work harder to take in air, ultimately pulling it in through minute cracks in the home's exterior. The HVAC system's parts may wear out sooner than they should, and ultimately, malfunction and fail.

You need to open the damper when you start a fire to allow for proper airflow and let the smoke out. A closed damper can restrict airflow and become a safety issue since smoke would fill your house.

The simplest way to close foundation vents for the winter is to plug them from the outside with foam blocks made specifically for this purpose. Just remember to remove the plugs when the weather turns mild in the spring.

Many homeowners think it's a good idea to close air vents in unused or infrequently-used rooms during the winter months in order to save money on heating. Should you do the same? The short answer is no. As a matter of fact, doing this can lead to the need for a home furnace repair.

Should vents be closed in unused rooms? ›

The short answer is no; you should not close air vents in your house. Closing vents can actually waste more energy than operating your system normally. How does closing air vents waste energy? Because when you close vents in unused rooms, your central air system will push the excess air to other places in your home.