Heating and cooling a home is one of the most significant expenses of running a household. So, when the weather turns colder, or the mercury starts to rise, many homeowners look for ways to cut back on costs and save energy. While there are a number of strategies that can be highly effective, one that should be treated with extreme caution is closing off vents in unused rooms. HVAC vents often have fins that are adjusted using a sliding switch. The fins can be used at a particular angle to direct airflow, but if you slide the switch all the way to one side, it can close the vent entirely. This may seem like an effective way to save energy; after all, why should you pay to heat or cool an unused room. Unfortunately, it may actually increase your utility bills and increase your risk of needing repairs in the long term.

A Counterproductive Approach

It appears to seem very logical; if heated or cooled air does not escape through vents into a couple of rooms, it should take less energy for the remaining rooms. But, an HVAC system isn’t designed to work in this way.

HVAC systems can be likened to the human body’s respiratory system. In order to work as designed, adequate airflow is needed. Most HVAC systems are calibrated, so that changes in airflow may compromise energy efficiency, putting excess strain on the system.

Closing off vents will increase the pressure inside your ductwork; this backs up into the system, and it is forced to work harder. In the same way as having a dirty filter, this will cause your air conditioner or furnace to use more energy to maintain your comfort level, pushing up the costs of your monthly bills. This increased pressure can also put additional strain on motors, fans, and other components, leading to more frequent repair issues and reducing the maintenance intervals. Additionally, the increased duct pressure may also cause duct leaks. Any weak spots in the ductwork may be turned into open gaps, so treated air escapes and the system is forced to work even harder.

Don’t Block Vents

Another tactic that is common among homeowners is to minimize airflow by obstructing the vents. Rearranging furniture so that pieces sit in front of vents may prevent bursts of hot or cooled air entering the room, but this acts in the same way as closing the vent itself. Again, you can put your HVAC system under increasing pressure, but you may also increase the risk of home damage. If a large piece of furniture is placed in front of a vent emitting heated air, the item will also start to heat up. If the furniture is flammable, there is an increased risk that obstructing the vent may cause a fire.

More Effective Ways to Save Energy

Fortunately, there are a number of more effective ways to save energy without compromising your home comfort or placing your HVAC system under undue pressure.

  • Use Window Coverings: The sun can be a powerful way to heat up a room. In summer, this can mean that your air conditioning needs to work harder to compensate. Fortunately, you can negate this with window coverings. In summer, ensure that south facing windows are covered by blinds or drapes, so direct sunlight does not enter the room. In winter, allow the sunlight to enter your rooms by opening blinds and drapes, following the path of the sun to add a little warmth to the room. You may be pleasantly surprised at just how warm the winter sun can be, allowing you to reduce your heating down by a degree or two.
  • Use Zone Controls: Zone controls allow you to safely use the concept behind closing vents in your home. Many newer style thermostats or the innovative smart thermostats allow you to designate different zones in your home. You can then independently adjust the temperature to your preferred levels in each zone. This means that you can avoid heating or cooling certain areas of your home and even adjust the temperature to suit your preferences. For example, you can set your sleeping areas to a cooler temperature in winter, while keeping your living areas a little warmer.
  • Adjust Your Thermostat: Another way to reduce your energy bills is to adjust your thermostat by even a couple of degrees. According to Department of Energy estimates, you can save approximately 1 percent on your energy bill for each degree per 8 hours. This means that you can save an impressive 10 percent on your annual energy bills by adjusting your thermostat by 7 to 10 degrees for 8 hours each day. So, rather than automatically setting your thermostat lower in summer and higher in winter, turn it down in winter and up in summer by just a few degrees to see some serious savings.
  • Turn Off Appliances: While you may be primarily focused on heating and cooling, you can also enjoy some impressive energy savings by being more energy conscious throughout your home. Appliances left on “standby,” lights left on and even simple things like filling your kettle when you only want to make 1 cup of tea will all waste energy. So, take a more proactive approach to your energy usage and go around your home to turn off appliances and lights when not in use.
  • Upgrade Your System: Finally, if you notice that your heating and cooling costs continue to increase, it may be time to look at upgrading your system. If your HVAC system is 10 or more years old, you’re likely to find that newer systems offer far greater energy efficiency and performance.

If you are concerned about your heating and cooling performance, be sure to speak to an experienced HVAC technician. A professional HVAC specialist can not only assess your system for any underlying issues that may be compromising performance and efficiency, but also advise you on further tips to increase your HVAC efficiency.