It’s a common misconception that closing vents in unused rooms can save money by reducing heating and cooling costs. However, this practice can actually increase energy consumption and put unnecessary strain on your HVAC system. When vents are closed, air pressure builds up in the ductwork, potentially causing leaks or damage to the system. Additionally, the imbalance of airflow can reduce the efficiency of the HVAC.
Rather than closing the vents, which can lead to higher energy use, we recommend adjusting your thermostat to a setting that doesn’t require your HVAC to work as hard. You may also want to consider ensuring that your home has the proper insulation to keep out cold in the winter and heat in the summer. Let’s dive in to discuss everything you need to know about closing vents and how to properly manage your HVAC system.
Does Closing Air Vents In Unused Rooms Save Energy?
Contrary to popular belief, closing air vents in unused rooms doesn’t save energy but can actually increase energy consumption. Many people assume that reducing airflow would lower heating costs in the winter or cooling costs in the summer. However, closing the vents creates an imbalance in the HVAC system, causing it to work much harder to maintain the desired temperature. Not only will this end up costing you more on your monthly energy bill, but it can also risk damage to your air conditioning and heating system.
HVAC systems maintain balanced air pressure throughout the home to ensure efficient airflow and temperature control. These systems rely on a network of ducts to deliver conditioned air from the furnace or air conditioner to different rooms. When air vents are open, air flows evenly through the ducts, maintaining consistent pressure in both supply and return vents.
Closing vents in unused rooms will disrupt this balance and create excess pressure in the ductwork. This pressure will lead to inefficient airflow and reduced system performance, which in turn can damage the system or cause air leaks.
Understanding Static Pressure
Static pressure in an HVAC system refers to the resistance to airflow within the ductwork when the air is not moving. It is a crucial factor in determining how efficiently air moves through the ducts to reach different rooms. If static pressure is too high, it indicates that the system is working harder to push air through the ducts, which can reduce airflow, strain the system, and increase energy consumption. Conversely, low static pressure may indicate that the system is not properly sealed or that air distribution is unbalanced.
For residential systems, normal static pressure typically ranges from 0.5 to 1.0 inches of water column (in. WC), although it can vary depending on system size and design. Proper static pressure management helps ensure that your HVAC system operates efficiently and effectively.
Consequences of Closing Vents in Unused Rooms
As mentioned above, closing vents in unused rooms can cause several issues within an HVAC system, primarily due to the imbalance it creates in the airflow. HVAC systems circulate air evenly throughout the home with an equal amount of supply and return airflow.
However, closing the vent disrupts this balance, causing air pressure to increase in the ductwork. Increased pressure in the ducts can lead to increased energy consumption and cause unnecessary wear and tear to your HVAC unit.
HVAC systems are expensive. While the cost depends on the make, model, size and region where you live, a new HVAC system can cost anywhere from $3,000 to $12,000 or more for a basic central air system, including both the unit and installation. To avoid such a large expenditure, we recommend doing everything you can to avoid overworking your current AC and heating system. Below, we explain how closing vents can be a costly mistake.
Increased Energy Costs
When you close vents, you disrupt the airflow balance within your HVAC, forcing the system to work harder to maintain the desired temperature. Pressure builds up in the ductwork, forcing the system to push air more forcefully through the remaining open vents instead of evenly spreading out airflow when all of the vents are open.
The increased pressure then increases strain on the system, ultimately leading to inefficiencies and driving up utility costs. The simple act of running your AC unit more will lead to higher consumption of kilowatt-hours per month, which will yield more expensive monthly energy bills.
System Damage
Another major problem with closing vents is the risk of causing damage to the ductwork. The increased pressure from closed vents can lead to leaks, cracks or even disconnected ducts, which would reduce the system’s effectiveness and efficiency.
The increased pressure can damage more than just the ductwork, but also damage:
- Blower motor
- Air handler
- Compressor
- Evaporator coils
Air Quality Issues
Closing vents can also negatively impact the air quality throughout the home by disrupting the proper circulation and filtration of air. When vents are closed, airflow becomes restricted, which can cause the air to become stale and stagnant. The lack of ventilation may lead to the accumulation of dust, allergens and moisture, which can reduce indoor air quality and potentially trigger respiratory issues. Closing vents also leads to poor filtration, as air filters cannot effectively trap particles or pollutants.
Better Alternatives To Closing Vents
Instead of closing vents in unused rooms, there are more efficient ways to manage temperature and energy usage throughout the home. These methods help balance airflow, optimize energy consumption and maintain comfort — without putting unnecessary strain on your HVAC system.
- Adjust thermostat: Set the thermostat temperature lower in the winter and higher in the summer to reduce your overall energy usage rather than trying to isolate a single room.
- Zoned HVAC system: Use a zoning system to control the temperature in different areas of your home independently.
- Improve insulation and sealing: Enhance insulation in walls, ceilings and ducts, and seal any gaps to prevent heat loss or gain.
- Use ceiling fans: Use ceiling fans to circulate air more efficiently rather than relying on your HVAC system.
By reducing your home’s energy usage as a whole, you may be able to lower your monthly energy costs and help prolong your HVAC system’s service life.
Frequently Asked Questions Closing Air Vents in Unused Rooms
How much money will I actually waste by closing vents?
Closing vents can increase energy usage by 10% to 20% due to the added strain on your HVAC system. Depending on your home’s size and system efficiency, this could lead to an additional $100 to $200 in annual energy bills.
Can I close vents temporarily during certain seasons?
It might be acceptable to temporarily close vents in unused rooms during mild seasons when the HVAC system isn’t running frequently. However, you should only do this for brief periods. If you do close vents, monitor airflow and pressure. You should also ensure your system is well-maintained to avoid damage or inefficiency.
What if I only close one or two vents?
Closing just one or two vents around your home can still disrupt the airflow balance, causing pressure buildup in the ductwork and forcing the HVAC system to work harder. While the impact may be less severe than closing multiple vents, it can still lead to reduced efficiency, higher energy costs and potential damage.
Will a zoned HVAC system solve this problem?
Zoned HVAC systems use multiple thermostats and dampers to control airflow to different areas of the home, allowing for independent temperature control in each zone. Unlike closing vents, zoned systems maintain balanced airflow, improving energy efficiency and comfort while preventing damage to the system.
