Charlotte HVAC Services Tip: Don’t close vents in unused rooms

January 17, 2016by Sophie The Dog

It is a common HVAC (heating, ventilation, and air conditioning) myth that closing the vents in unused rooms of your home will save you money on energy costs. This is simply not true. By closing the vents in certain parts of your home that are unused or little used, you are actually doing more harm than good. This practice can cause immediate and even long-term damage to your heating and cooling system. By trying to save a little bit of money, you may end up costing yourself more money in repair costs and potentially a lot of money for a new system. Avoid unnecessary calls to Patterson by keeping all of your vents open.

Closing vents does NOT save energy

Let’s compare your heating and air system to your own respiratory system. When you breathe, you inhale and exhale as the air circulates through your lungs and back out again. If you are moving a lot or exercising, you will be breathing heavily and your body will be working hard to supply all the parts of your body with oxygen. Imagine breathing in through your mouth and out through your nose. Now imagine that one of your nostrils is blocked, but you are still breathing heavily and exerting yourself. Your body still needs the same amount of air, but you have fewer passages for the air to get out. Will you find it easier to breathe in this situation, or more difficult? You will obviously have to work a lot harder to breathe with one nostril blocked.

Your heating and cooling system works basically the same way. It draws air in through the larger return vents in your home and pushes air out through the smaller and more numerous supply vents. The supply vents are like your nostrils. If you close one or more of the vents the air comes out of, your furnace or air conditioner will have to work much harder. The pressure in the ducts will increase, causing your blower to slow down, which reduces the air flow over the heating and cooling units and throughout your home. If your blower is the type that self-adjusts to the current conditions, it will work harder to balance out the extra pressure. Both of these options cause an increase, not a decrease, in energy usage by your HVAC system.

You could be damaging your HVAC system

Closing some of your vents can damage both your furnace and your air conditioner because of decreased air flow.

  • Air conditioning: Less air flows over the evaporator coil, which is the part of your air conditioner that contains the refrigerant and cools the air. If there is not enough warm air blowing over the coil, it will overcool itself and freeze up. The risk here is that the liquid refrigerant may flow to the compressor in the outdoor unit, which can do irreparable damage.
  • Furnace: If there is not enough air moving over your heat exchanger, it will overheat. This can cause the heat exchanger to crack, which cannot be repaired. A new heat exchanger is an expensive part, and if a new exchanger is needed, it may just be best to replace your entire system.

More reasons not to close vents:

  • Decreased home comfort – Less overall airflow throughout your home will lead to a less comfortable home. You will not feel as warm in the winter or as cool in the summer, and your house may feel more “stuffy.”
  • Increased duct leakage — The extra pressure in your ducts that results from the closed vents may cause leakage in your ductwork. These leaks are not reversible by simply opening the vents again. Leaks have to be repaired by professionals.

Patterson Heating and Air Conditioning has your best interest at heart

Why do we offer this kind of free advice? Because we care about our customers. We don’t like to see our loyal customers make mistakes that will cost them money when it could have been avoided. At Patterson we work hard to earn your trust. But if for any reason you are in need of Charlotte HVAC services, we will repair or replace your furnace or air conditioner quickly and efficiently. Schedule appointments here or call us at (704) 288-4535.

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Charlotte, NC 28206


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