According to the US Energy Information Administration, homeowners can expect a 4% to 5% increase in their electric and gas bills this winter season. If you heat your home with propane, you may see a whopping 21% increase.

Although stockpiled resources may help keep these electric, gas, and propane prices in check, you naturally want to do everything you can to keep comfortable without sacrificing your hard-earned income. From installing new weather stripping to hanging heavy drapes, you'll likely try all of these techniques if you can save money and stay warm.

But before you follow every piece of money-saving advice from friends and family, take a few moments to research the effectiveness of your method. Closing air vents, for example, might seem like a logical way to conserve heat, but it could ultimately cost you more money than you anticipated.

Rather than effectively redirecting heat away from unused rooms, closed air vents may result in the following problems.

1. Pressure and Heat Imbalances

Your heating system depends heavily on its blower to pull outside air into your home and push the heated air through the ducts. Although some high-efficiency systems can adapt to varying conditions, most units are designed to push against a set pressure difference.

When you close vents in your home, you restrict the air that flows through your ductwork, increasing the pressure. As the pressure goes up, the motor can't push the fan fast enough to overcome the resistance from the air pressure. The fan slows, and the amount of air that passes through your heat exchanger drops.

As a result, your home will take longer to heat, even if you only want to heat a few rooms. 

2. Heat Exchanger Damage

Your furnace's heat exchanger consists of a set of tubes and coils that loop repeatedly through your unit. As hot combustion gasses enter the heat exchanger, they circulate through those tubes, and the heat transfers to the walls of the exchanger.

When cold air passes over the heat exchanger, it absorbs the heat from the exchanger walls without picking up the combustible gasses. The warm air then blows around your home and the now-cool gasses pump outside.

But if you were to close too many air vents, the amount of air that flows over your heat exchanger decreases. Without enough air to absorb the heat from your heat exchanger walls, the heat builds up until the tubes crack and leak. If left unrepaired, the cracks allow dangerous carbon monoxide to mix with your heated air, increasing the likelihood of carbon monoxide poisoning.

3. Ductwork Leakage

According to Energy Star, approximately 20% to 30% of heated air leaks out of holes in your ductwork. Consequently, your furnace has to work that much harder to ensure your home maintains a comfortable temperature, and your utility bills will often reflect that energy loss.

As mentioned above, closed air vents increase air pressure in your ductwork, and that extra pressure forces more air out of those gaps and poorly fitting connections. Instead of directing heat to your living room or bedroom, you're now paying to heat the spaces in your walls, attic, and crawl space. Additionally, you run the risk of forcing more air through those gaps than your ductwork can handle, and it may split even further. 

Although leaving air vents open won't solve leaking ductwork, it will keep your ductwork from bursting and costing you hundreds of dollars in repairs.

4. Moisture Buildup and Mold Growth

Mold prefers to grow in damp environments, such as bathroom cupboards and unfinished basements. But it will grow just about anywhere if given the opportunity and the right circumstances.

When you shut off one or two rooms in your house, you significantly reduce the air flow that travels into and out of those rooms. The air already in the room will be unable to absorb additional moisture that evaporates from your furniture and flooring, and the buildup will leave these items constantly damp.

Furthermore, your air vents and ducts will still leak some air, despite the closed register. When the heated air comes in contact with the cold metal, the temperature difference will cause condensation to form. The condensation combined with any dust and debris blowing in from the air vent will provide everything mold needs to thrive.

Find Better Ways to Save on Heating

If you want to save on heating this year, don't expect closed air vents to come to your rescue. Rather than permanently damaging your heating system, call in an HVAC technician and ask for furnace repairs and inspections. When you keep your furnace in great shape, you can significantly improve your unit's energy efficiency and ensure your home stays consistently comfortable.

If you need additional ways to save, your HVAC technician can help you find air leaks and advise you on the best methods for locking in heat.