The added pressure from closing a vent can cause several problems in your HVAC system and, ultimately, waste energy. So, does closing your vents save energy? Our experts say no — it does not save energy, and you are better off keeping vents open.
Blocked vents increase air pressure in your ductwork, which can create cracks and leaks. Clear vents ensure every room in your home gets good circulation so your system can work as designed. Have a piece of furniture sitting over a vent? Try using an inexpensive vent extender to direct air out into the room.
You should never block an air vent in a bedroom as this can cause problems in air circulation, humidity, and toxic mold. As part of the HVAC system, air vents help properly circulate air around your home, and by blocking an air vent you can damage your HVAC system which can be very dangerous.
Harms Energy Efficiency
Unlike the myth states, closing vents increases energy consumption and costs. The air conditioning system doesn't know when you close your vents, which can cause the heating system to overwork to heat the space it is designed for.
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.
Impact on HVAC Efficiency: Covering vents disrupts airflow, forcing your heating and cooling system to work harder, which can lead to uneven temperatures in the room and higher energy bills. This strain may also shorten the lifespan of your HVAC equipment.
May Cause Mold Growth
A closed vent in an unused room can cause mold and mildew growth. Worse yet, those spores can then make their way into other parts of the house since the room isn't sealed airtight.
Block Off the Vent: You can block the vent by placing a piece of furniture at the opening or purchasing a magnetic damper that's strong enough to stick to the steel on the wall or ceiling. Plastic sheeting can be placed over the opening as well. You can also install a vent grille filter.
Shutting Heating Vents in the Summer to Conserve Energy
Leaving vents closed for extended periods can cause damage and expensive leaks. That's why we recommend rotating which vents you close every few days. Doing so will help keep your HVAC system in great shape and lower your monthly energy bill.
Is it okay to vent without asking? In general, it's best to only vent to someone if they've discussed that they're able to receive it in that moment. If not, it could be difficult or even harmful for them to receive the full force of your emotions.
You most likely thought covering your air vents would certainly save you energy, but it does the opposite. Considering that this could damage your cooling and heating system, fractures and other damage could allow air to leave your air ducts and cost you much more in energy bills.
So how much space does an air return vent need to work properly? Home Inspection Insider explains that an air return vent needs 6-12 inches of space in front of it, and recommends that you do not put large, bulky furniture like couches and bookshelves in front of an air return vent.
Hiding a Wall Air Vent
Place a piece of tall furniture in front of the wall vent to hide it. Alternatively, hang small pictures, awards, or floating shelves in front of the air vent. For a more permanent solution, install a drywall vent cover that matches the design of your home.
A build up of pressure can be caused by covered vents. This could lead to a cracked heat exchanger which in turn can lead to leaking carbon monoxide. Covering your vents can damage your HVAC system and cause cracks that could allow air to escape your ducts. This can lead to higher energy bills.
While blocking air bricks may seem like a good way to keep the cold out, it can cause more harm than good. Covering these vital vents stops fresh air from flowing into your home. This lack of airflow leads to damp and moisture buildup. Damp conditions are perfect for wood rot and mould growth.
An easy indication that your air ducts are dirty or clogged is when the system turns on, you may see a cloud of dust coming out the air vents. You can double-check this by turning off the HVAC system and waiting a few minutes after it has shut down.
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.
It is typically best to always leave your air vents open, even in unoccupied rooms. It may sound counter-intuitive, but leaving vents open will use less energy, extend the life of your HVAC unit and save you more money in the long run.
EXPERT RECOMMENDATION: If you want to try to balance the airflow throughout your home, you should not close vents completely; HOWEVER, you can close them slightly (not more than 75% closed) to help distribute air better to the areas that need it most.
If you block an air vent with your furniture, with tape, or otherwise, you will negatively impact your HVAC system and the air quality and comfort of your home.
Our advice? Don't block air-bricks or internal vents unless a flood is likely. If you have dampness or mould growth, check gutters, rendering and pointing as it may be letting water in. Check for slipped or missing slates or tiles.
When vents are obstructed, heat can build up in the ductwork, increasing the risk of a fire. Additionally, if flammable materials are placed near blocked vents, the chances of a fire spreading rapidly are heightened. It is crucial to keep your vents clear of any obstructions to minimize the risk of fire accidents.
You may tamper with the airflow
The system will continue to pump air through those vents, and if you leave them closed, you may see an increase in air pressure and a decrease in airflow, both of which might cause harm to your system.
Closing air vents can lead to increased pressure in the ductwork, damage to the HVAC system, mold growth, and safety hazards, such as carbon monoxide infiltration. It's best to keep the air vents open to prevent these risks.
Obviously on a hot summer day, the outside air will take lots more energy to cool than already-conditioned inside air would. This again means that you'll be wasting energy. To maximize the efficiency of your HVAC system as well as your comfort, don't close off unused rooms.