Open Vent: Open vents help maintain a consistent temperature throughout your home. This is particularly important if you have a multi-story house, as closing vents on one level can lead to uneven
You might think that you can save energy by closing off the vents in unused rooms, but that's not the case -- not only can this cost you more on your utility bills, but it can also cost you more in repairs over the long haul.
Vents should be open. Closing them can actually put strain on the system and cause damage. It is not more efficient to close vents. The system is pushing out the same amount of air regardless of whether vents in any given room are open or closed, and it's designed to operate efficiently with all vents open.
If it's cold outside and your vents are located near the ceiling, then you need to point the vents downward. Your goal is to increase the circulation of air inside each room as much as possible.
In winter, particularly in cold climates, closing crawl-space vents can help prevent cold air from entering the space and potentially freezing pipes. 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.
(Hint: In the summer months, open the top vents and close the bottom ones to draw out air from a higher point in the room where it's hotter).
Some experts suggest that it is better to turn the system off in very humid weather to keep indoor humidity levels low. You can also set up the system so that it only runs when the air conditioning system is running, or use pre-cooling coils.
(CFM) When you close off a supply or return vent, the system is no longer balanced. This can cause insufficient cooling or heating, and will shorten the lifespan of your indoor fan motor.
Keep your home ventilated
Open windows at least once a day, keep window trickle vents open, and air vents uncovered. It's important that air can move through your home as ventilation is one of the best ways to avoid mould, as flowing air means spores can't settle somewhere and absorb water.
Install More Return Vents
Supply air and return air need to be balanced, but there's no such thing as too much return air. By installing more return vents throughout your home, they can trap the air and remove it, improving air circulation.
Closing air supply vents increases the air pressure inside the air ducts, which backs up into the ductwork of the home and can cause leaks.
Although closing off unused rooms may seem like a way to save energy on heating and cooling, it can actually force your HVAC system to work harder. In order for your air conditioner to work efficiently, you should keep the interior doors in your home open as much as possible.
First, heat rises, so it's normal for the second floor of a home to get hotter than the main floor.
✅ Keep all vents open to maintain your system's designed airflow. This ensures air conditioner efficiency and comfort without straining your system.
One common strategy is closing air vents in unused rooms or little-occupied areas to redirect heat and increase efficiency. While this might seem like a smart, cost-effective solution, it can actually increase energy consumption, strain your HVAC system, and lead to costly repairs.
When doors inside are closed, pressure differentials are created. This causes your AC to work harder to ensure a steady airflow. Also, keeping the doors open can minimize the strain on your HVAC system. This translates to better energy efficiency and substantial savings.
Although the vent can be closed, they are designed to be left open all the time for continual ventilation. Trickle vents are especially important in modern houses as homes are designed to be more airtight. A constant trickle feed of air helps to remove excess moisture buildup from the air that can cause mould.
Closing the vents doesn't do it any favors. In fact, instead of helping the air conditioner cool less, closed registers force the same amount of air through other ducts. This builds pressure in the system and makes your HVAC system work harder to distribute the air where you need it.
You should never block your air return vents. Period. However, if you're looking to keep your home cooler in the summer, you can try closing lower supply vents and keeping upper ones open, allowing cooler air temperatures to come in from above and sink throughout your house.
Another problem you might have could be dirty air vents. Dirty air vents can block air from getting through just like objects can, and they could be the answer to your question of “Why is it so cold in my house?”
We recommend running the whole house fan all night. The goal is to cool your entire house down, not just the air. It takes time to pull the heat out of the sheetrock, structure and contents of a house.
Static pressure in your air vents
Static pressure is the resistance to airflow in your HVAC system. These systems are designed to have the right balance of static pressure. Closing vents will increase the pressure, which can restrict or stop efficient airflow in your home.
Persistent Odors: Homes should refresh and clear out odors naturally through proper ventilation. If cooking smells, smoke, or other odors last longer than they should, it's likely your home isn't circulating air properly.