Should You Close HVAC Vents in Unused Rooms

On an intuitive level, it can feel like closing vents will save you money. In reality, this decision can create more problems than it solves. If your home has a central heating, ventilation, and air conditioning (HVAC) system, closing vents will likely cause more damage and higher energy costs than leaving them open.

Why People Close Air Vents in Unused Rooms

As a homeowner, it feels wasteful to heat and cool rooms you don’t use. It feels logical to shut vents to stop conditioned air from reaching your guest rooms or spare bedrooms. While this might seem like a DIY solution to high energy costs, it could end up costing you more money in repairs and energy expenses in the long run.

The Myth Behind Closing Your Vents

The biggest reason closing your vents doesn’t help is that it doesn’t impact how much air your HVAC system produces. Residential HVAC systems are made to produce and move a set amount of air. If you block the vents, all that happens is you change the air pressure inside the ductwork. The actual workload remains the same.

Does Closing Air Vents in Unused Rooms Save Energy?

In most instances, closing air vents won’t save you energy. The unit will likely run for the same amount of time. Because of the closed vents and resulting air pressure increase, the HVAC system may even have to work harder. As air pressure in your ductwork rises, duct leakage becomes a bigger problem.

The only way to reduce the air sent to unused rooms is if you have zoning or variable-speed equipment. With variable-speed units, the amount of conditioned air can drop. This causes less strain on your system’s components. Similarly, HVAC zoning lets you control each zone with its own thermostat, which allows you to reduce energy consumption without shutting any vents.

Does Closing Vents Redirect Air in Your Home?

Closing vents might cause air to move somewhere else, but it won’t be in a controlled fashion. Instead, you’ll end up with an uneven distribution of conditioned air reaching each room. Often, the rooms that are the farthest from the system will feel the least comfortable. Instead of trying to redirect air with closed vents, we recommend scheduling professional airflow balancing instead.

What Does Closing Air Vents Actually Do?

When you close air vents, you increase static pressure throughout the duct system and restrict airflow where the vents are closed. Unfortunately, this doesn’t mean that the air ends up evenly distributed everywhere else. Instead, each room is cooled or heated unevenly. Over time, closed vents can result in poor energy efficiency, declining comfort levels, and worse equipment performance.

Static Pressure in Your Air Vents

Static pressure is the pressure the blower must overcome as air moves through the duct system. When you close vents, the pressure increases because there are fewer places for the air to go. This pressure causes added strain on the ductwork and blower motor, eventually resulting in premature breakdowns

Problems That Result From Static Pressure in Your Air Vents

If the static pressure in your system is too high, it can lead to a few common issues.

• Reduced System Efficiency: Your system must work harder to condition your home, leading to reduced energy efficiency and poor HVAC performance.
• Hot and Cold Spots: The air is redirected unevenly, so even your conditioned rooms will end up with uneven temperatures.
• Noisy Vents or Ducts: Due to the increased pressure straining the ducts, the ductwork may produce creaking and groaning noises.
• Increased Duct Leakage: As the pressure rises, the air needs to go somewhere. While most of the air will come out of a different vent, the increased pressure can lead to more air coming out of duct leaks.
• Frozen AC Coils: Poor airflow can reduce the amount of heat absorbed by the evaporator coil, causing the coil to freeze.
• Overheated Furnace: Similarly, poor airflow can lead to the furnace overheating. This can trigger a safety shutdown.
• Wear on Components: Because the HVAC system has to work harder to maintain the same temperature, it can lead to extra wear on blower motors and HVAC parts. 

Should You Close Vents in Summer or Winter?

The same essential rule applies year-round. You should never fully close multiple vents unless specifically told to do so by an HVAC professional. Closed vents in the summer can decrease airflow over the coil, resulting in freezing and poor performance. In the winter, it can trap heat in your system and cause overheating.

What To Do Instead of Closing Vents

Rather than closing your vents, we recommend using the following steps instead.

• Keep the majority of your vents open. Make sure they aren’t blocked by furniture or curtains.
• Use a programmable or smart thermostat to set a comfortable temperature in your home.
• Replace your air filter every 30 to 90 days. During periods of peak usage, it should be replaced more often.
• Seal leaky air ducts.
• Call our team to have your airflow professionally balanced. 
• Schedule a tune-up before the peak heating or cooling season arrives.

If your home has persistent comfort issues, book an evaluation with our team. We can set up zoning in your home so that each area can have its own comfort settings.

Tips for Keeping Your Home Comfortable and Reducing Energy Bills

If you want to maximize your home’s comfort and energy efficiency, the following best practices can help.

• Use ceiling fans correctly for the time of year. Your fan should spin counterclockwise in the summer to push the air down and ensure a cool breeze. In the winter, they should spin clockwise to circulate heat without making a draft.
• Prevent heat from entering your home by closing your curtains and blinds on hot summer afternoons.
• Try to leave your interior doors open so that air can circulate.
• Keep furniture, curtains, and other items from blocking the supply and return vents.
• If some rooms are consistently uncomfortable, you may need to upgrade the insulation.

Optimize Your HVAC Airflow and Performance

While closing air vents in unused areas may seem like it would improve your energy efficiency, it often results in increased pressure, strained components, and premature repairs. For the best balance of comfort and efficiency, homeowners in the Bandon area should optimize their ductwork, airflow, and thermostat settings.

Reach out to Alpha Heating & Air for your next ductwork inspection, routine maintenance, or airflow balancing.