In general, it is usually OK to close vents in a basement. It is on the main floor that you probably do not want to close any vents. Your furnace fan is moving cool air in the summer months. Without a fan running, the air in your home stratifies, with warm air moving to the highest levels of the house. Just so, should vents in basement be open?
Whether your vent is open or not, the warm air is still going to try to push through to each vent. When the vents are closed the air won't be able to come easily through the vent. Instead, it will be forced through any crack it can find in the duct work or other areas that aren't sealed properly.
Additionally, is it OK to close heating vents? Regardless of how many vents you have open, the heater or air conditioner produces the same amount of air. The added pressure from closing a vent can cause air leaks in your system, causing long-term and unnecessary energy waste. So does it save energy to close vents in unused rooms? The answer, unfortunately, is no.
One may also ask, which vents should be open in summer?
In the summer you want the cold air to remain and the hot air to be drawn out through the return registers. By closing the floor registers and opening the ceiling registers you force the hot air out while keeping the cold air in the room.
Should I keep all my vents open?
Open All the Air Vents in Your Home By opening the vents, you will reduce pressure buildup, heat buildup, and an imbalanced circulation of air. You may also want to have your air ducts or furnace cleaned to ensure that the air is flowing properly through your home.
Related Question Answers
Should vents be open or closed in winter?
These vents allow outside air to circulate under the floor in summer to prevent the moisture buildup that encourages mildew and rot. In winter, when the air is drier, the vents are closed to reduce the chance that the pipes in the crawl space might freeze. Should I close AC vents in basement?
Reason #1: Closing vents restricts airflow Closing vents disrupts this balance and creates pressure in your system, which causes your air conditioner to work harder. This can increase your energy bills and even lead to premature breakdown of your AC if you close too many vents. Does closing vents downstairs help cool upstairs?
Opening upstairs cold air supply registers fully and all but closing downstairs air supply registers helps direct the cold air upstairs. You are literally rerouting the circulation of the air pushed out through your air conditioner. When should I close my basement vents?
These vents allow outside air to circulate under the floor in summer to prevent the moisture buildup that encourages mildew and rot. In winter, when the air is drier, the vents are closed to reduce the chance that the pipes in the crawl space might freeze. Should I keep basement vents open in winter?
If you really want to save some cash on your bills, keep your vents open and allow the air to flow freely throughout your home, but consider lowering the temperature a few degrees. You probably won't notice a temperature difference, but your system will be happier without the closed vents and you will be saving money. Does closing vents increase airflow?
Closing air vents increases the pressure in your ducts. If they're well-sealed, this may increase the airflow somewhat to other parts of the home. However, the heated or cooled air may travel a very inefficient path to get there, ultimately decreasing the efficiency of your system. Should I close my central air vents in winter?
In extreme cold, the lack of warm air in your duct work may cause freezing to occur. Don't shorten the life of your HVAC system unnecessarily by closing off your vents. Should vents under house be open or closed in summer?
These vents allow outside air to circulate under the floor in summer to prevent the moisture buildup that encourages mildew and rot. In winter, when the air is drier, the vents are closed to reduce the chance that the pipes in the crawl space might freeze. Should I close my downstairs vents in summer?
If you have more vents than you need then perhaps you can shut some. In general, it is usually OK to close vents in a basement. It is on the main floor that you probably do not want to close any vents. Your furnace fan is moving cool air in the summer months. Is it OK to close vents in unused rooms?
Despite that logic, it's actually a common misconception that closing vents in unused rooms saves energy. In fact, it can actually waste more energy than operating your system normally does. The added pressure from closing a vent can cause air leaks in your system, causing long-term and unnecessary energy waste. Should an AC vent be open or closed?
Why you should keep your vents open When you close AC vents, you increase the pressure inside your home's ductwork. As pressure inside the ducts increase, more cool air (that you've paid for) gets pushed out of duct leaks. You see, the typical home already loses about 30% of conditioned air to leaky ductwork. Should return vents be high or low?
For optimal efficiency, it's ideal to have return registers installed. To ensure efficiency during the cooling season, your home should have high registers. High return registers draw hot air that rises to the ceiling back into the system to repeat the cooling cycle. Should I open the vent on my air conditioner?
Bottom line: Leave your AC vents open! If you want a healthy AC, a comfortable home and reasonable energy bills, you should always leave your AC vents open (even in unused rooms). Can you block a return air vent?
Blocking air return vents causes your system to work harder, as there is less air flow to move the air back to the furnace. This continued strain on the HVAC system can lead to a decrease in performance and more HVAC repairs down the road. Why is one room colder than the rest?
If some rooms are warmer or colder than others, this is usually just a matter of balancing. Meaning adjusting the airflow to each room so they all even out. If a room is heating or cooling much quicker than other rooms, the airflow can be reduced to that room to even things out, also sending more air to other areas. What happens when you close heat vents?
Closing off vents creates unexpected blockages, which forces the furnace to work harder when distributing heated air. It's also possible that limited air flow, especially in winter, may cause freezing in your ducts, meaning more work for your heating and air conditioning system. Can you block a heating vent?
Though you should never say never, blocking a heater vent to redirect warmth inside your house is normally a safe way to save money by increasing energy efficiency. It would require a massive failure of built-in safety systems for the heat to get hot enough inside a blocked vent box to cause any danger of fire. Does closing vents make other rooms warmer?
Because heat rises, the top floor often steals most of the heat. Partially closing vents can help keep other areas warmer without damaging or stressing your HVAC system. Is mold on air vents dangerous?
However, indoor mold growth can be dangerous, especially when it is located in your HVAC system's ductwork, coils, and drip pans. Since ductwork circulates air throughout your home, mold growth located in the ducts or around the entrances to the ducts could mean your family will be breathing unhealthy air. Is it OK to cover air vents?
You could mess with the air flow. Just because you cover the vent, it doesn't mean your HVAC system knows that. It will keep pushing air to those vents, and if they're closed, you could cause a buildup of air pressure and insufficient airflow which could damage your system. Can blocking a vent cause a fire?
Fire, Freeze and Financial Hazard When a vent is blocked, less cool air flows across the heat exchanger, which then overheats, and expands, and cracks. It's unlikely but not impossible that blocking a heating vent and causing the furnace apparatus to overheat could cause a fire. Does closing AC vents make other rooms colder?
Does Closing Vents Help Other Areas of the House? Closing air vents in one area of the home does not help other rooms receive better airflow. Instead, conditioned air is lost through duct leaks and the other areas of your home do not receive additional heating or cooling. Does a house need air vents?
Many appliances and vents combine to properly ventilate a home. Houses need to breathe. They should draw in fresh air and exhaust stale air. But the trick is to provide needed ventilation without sending expensive home-heating and cooling energy dollars out the window. 
