Windows, doors, and HVAC

Windows, Doors, and Your HVAC System

Rod Johnson Cooling and Air Conditioning, Heating and Furnaces

When you think about your home HVAC system – meaning your furnace, your air conditioner and all of the associated ducts that go with it – you often don’t consider the other elements of your home that may come into play to ensuring that your system is running as smoothly as it could be.

Certainly, you should be doing a spring and fall checkup of your system to ensure that the electrical system is well connected, that the ducts are clear, and that your furnace and AC unit are in good working order.

However, your windows and doors play a huge role in an ensuring that your HVAC system is running in tip-top shape. Let’s take a look at some common problems that you can look for with both and some easy ways you can fix them.


Your doors are meant to let you and your family in and out. If they’re letting air in and out when they’re shut, that’s a problem. Unfortunately, many doors, regardless of design, aren’t sealed appropriately. Take a moment and check around your door for air draft or even worse, daylight. If you find either, head down to your local home improvement store and grab some weather stripping. You’ll want to do your best to seal that gap.

Screen doors with window inserts can also help a great deal in ensuring your air is staying inside your home. By creating an additional barrier between the inside and outside of your home, you’re making it much harder for air to escape.

Let’s take the winter time as an example. Your heater is working as it should because you’ve had the system tuned. But air could be flowing in through gaps in your door. Because the air is flowing in – and warm air is flowing out – your furnace and blower system has to work harder. This increases your energy use, which is bad for the environment and bad for your wallet.


It’s important to remember that many of the same principles that apply to doors apply to windows as well. You should inspect the seals around your windows and see if you feel air coming through. If you do, a bit of caulk can provide an easy and cheap solution.

Windows, however, provide an additional wrinkle. The glass within the window itself can let cold or warm in. Windows generally come in one of two thicknesses, double- or single-paned. Many older homes have single-paned windows – this means that your window only has a single sheet of glass in it. Double-pane windows have two panes, with gas in between the two, which blocks UV rays and keeps out heat and cold. Newer windows are even temperate to the touch.

If you have older, less efficient windows, an upgrade is always a great option, but that can be expensive. Take the time to do your research. In the meantime, look around your house and find windows that could benefit from a bit of caulk or weather stripping. Your HVAC system and your bank account will thank you.