Closing Doors For Energy Efficiency: Myth Or Fact?

Many people believe that closing the doors to unused rooms will help save energy and reduce their utility bills. However, this is a common misconception. Closing doors to unused rooms can actually increase energy consumption and utility bills. This is because closing doors obstructs airflow, which HVAC units need to function optimally. The air in the room becomes pressurised and escapes through openings in walls, windows, or vents, creating a continuous draft. This draft can lead to dust, humidity, dirt, and even carbon monoxide entering the room, creating an uncomfortable and potentially dangerous environment. Therefore, it is recommended to keep interior doors open as much as possible to allow for proper airflow and save energy.

Closing bedroom doors increases energy consumption

Closing your bedroom door before leaving the house or going to sleep may seem like a good idea to save energy, but it can actually have the opposite effect. Here's why:

Obstructed Airflow and Increased Pressure

Closing bedroom doors obstructs the airflow in your home. Your HVAC (heating, ventilation, and air conditioning) system needs proper airflow to function optimally. When doors are closed, the air in the room becomes pressurized, and this pressurized air needs to escape. As a result, air leaks out through any openings, such as cracks or gaps near windows, doors, walls, or even into the attic. This escape of conditioned air is a waste of energy.

Negative Pressure and Air Quality Issues

When the bedroom door remains closed for extended periods, the room experiences negative pressure. This means that air gets sucked into the room through the same cracks and openings that the pressurized air escaped from. This incoming air may be unconditioned, leading to an increase in temperature and a potential decrease in air quality. The continuous exchange of air due to pressure changes can also create a draft in your home.

Overworking of HVAC Systems

By closing bedroom doors, your HVAC systems have to work harder to maintain the desired temperature in your home. The system has to compensate for the loss of conditioned air, leading to increased energy consumption and higher utility bills. Additionally, the increased duct pressure can result in lower airflow, further reducing the efficiency of your HVAC unit.

Recommendations

To improve energy efficiency and maintain a comfortable indoor climate, it is recommended to keep bedroom doors open as much as possible. This allows for proper airflow and helps your HVAC system function at its best. If privacy is a concern, consider keeping the door slightly ajar or installing "transfer grills" to prevent air pressure buildup.

Additionally, regular maintenance of your HVAC system, such as changing or cleaning filters, vacuuming vents, and ensuring proper insulation and caulking, can significantly improve energy efficiency and reduce energy costs.

Closed doors obstruct airflow

Closing bedroom doors does not improve the efficiency of your HVAC system and may increase your utility bills. This is because closed doors obstruct airflow, which can lead to pressure issues and air leaks.

When a door is closed, the air in the room becomes pressurised. This pressurised air then escapes through any openings in the walls, windows, ceiling, or floor. This means that the cooled air is being pushed out of the room, wasting energy. The room's air must then be replaced, increasing the load on the HVAC system, which has to work harder to heat or cool less space.

Closing doors can also lead to negative pressure issues, where air is sucked into the room through the same openings that it escapes from. This can allow unconditioned air to enter the room, increasing its temperature and reducing air quality.

To improve energy efficiency and comfort, it is recommended to keep doors and vents open to allow for proper airflow and ventilation. Keeping doors open will help maintain a consistent temperature throughout the home and reduce the workload on the HVAC system.

In summary, closed doors obstruct airflow, leading to increased energy consumption, pressure issues, and reduced air quality. To optimise energy efficiency, it is best to keep interior doors open as much as possible.

Air pressure increases in closed rooms

Closing the doors to unused rooms in your home will not reduce the amount of space you need to heat or cool, thus lowering your energy costs. In reality, closing doors and vents in unused rooms can actually increase your energy use.

Heating and cooling systems are designed for balance, so that the amount of air returned to the air handling unit is roughly equal to the volume delivered through the supply vents in each room. When doors are closed, room air pressure increases. The extra pressure pushes air out through any openings in walls or windows. Rooms with closed doors can leak air in increased amounts.

The air in the room becomes pressurised due to the obstruction. But that pressurised air has to go somewhere, so it finds ways to escape. Then, that air is replaced by incoming air: through the chimney, the furnace flue, or even the water heater. This creates a continuous draft in the interior of your home.

The increased duct pressure results in lower airflow with fixed-speed blowers and increased energy use with variable-speed blowers. So, although shutting doors may sometimes be necessary for privacy or a little quiet time, it's not a good way to reduce your energy bills.

Air escapes through gaps in windows or the attic

Closing the doors to unused rooms in your home will not reduce the amount of space you need to heat or cool, thus lowering your energy costs. In reality, closing doors and vents in unused rooms can actually increase your energy use and your utility bills.

When you close a door, you obstruct the airflow in your home, and your HVAC unit needs proper airflow to function at its best. The air in the room becomes pressurized due to the obstruction, and this pressurized air has to go somewhere, so it escapes through any openings in walls, windows, or gaps in the attic. The increased duct pressure results in lower airflow and increased energy use.

To prevent air from escaping through gaps in windows, you can caulk around windows and doors, replace old windows or add storm windows, and beef up your weatherstripping.

To prevent air from escaping through the attic, you can seal attic air leaks, increase attic insulation, and encapsulate the crawl space. You can also use an attic fan to help regulate the temperature.

HVAC systems overwork themselves

Closing doors to unused rooms does not improve the efficiency of your HVAC system and may even increase your utility bills. When you close a bedroom door, you obstruct the airflow, and that blockage can lead to issues with airflow. This can cause cold drafts in the winter, high humidity in the summer, and even mould.

• Constant operation: Your HVAC system is designed to cycle the air in your home infrequently to conserve energy. It should not be running all the time without stopping. If it is, this indicates that it is overworked and wearing down.
• Increased energy bills: A spike in your energy bills could be due to your HVAC system working harder, possibly due to an obstructed fan or a burnt-out motor.
• Frequent breakdowns and repairs: A well-maintained HVAC system should not require constant servicing or repairs. If it does, it may be a sign that the system is nearing the end of its life or is too small for the building.
• Loud noises: A properly functioning HVAC system should be quiet. Noisy operation could be due to loose parts, clogged ducts, obstructed fans, or compressor problems, all of which cause the system to work harder.
• Leaking: If your HVAC system is leaking, shut it off immediately and call for emergency repair. Leaking refrigerant is extremely poisonous and can be harmful or even fatal.
• Inconsistent temperature: When the HVAC system is working correctly, the whole house should be the same temperature. If there are warm or cool spots, it could be a sign that the HVAC is too small or struggling with ductwork leaks.
• High humidity: When an air conditioner is functioning properly, it automatically dehumidifies the air. If your home is humid, it could be a sign that your AC is not functioning efficiently enough.

To improve the efficiency of your HVAC system and reduce the risk of overworking it, consider the following:

• Ensure proper airflow by keeping doors and vents open and clear of obstructions.
• Regularly change or clean your furnace filter.
• Schedule routine maintenance and inspections to address any issues and improve efficiency.
• Seal any air leaks or gaps in windows and doors to maintain a stable indoor temperature.
• Ensure proper insulation in walls and attics, especially if your HVAC system is older or in need of repair.

Frequently asked questions