April 19, 2022

Should I Open My Windows at Night to Save Energy?

It is a popular belief that opening windows at night will cool your home and save you money since your air conditioner is off. Initially, the answer to this question seems obvious. If you turn off the air conditioner, you are not using energy to cool your home. However, there are many factors that could influence whether this is a wise choice and how much actual energy you can save.

You might be surprised to learn that under certain circumstances, opening your windows at night to cool your home can cause you to spend more money and use more energy to cool your home. Here, we weigh the pros and cons to help you make an educated decision.

The Pros and Cons of Opening the Windows at Night

If you are like most people in Las Vegas, you have your thermostat set at about 67 degrees during the summer months. In late summer and early fall, nighttime temperatures in Las Vegas stay at around 70 degrees or higher.

When you open your windows at night, the cooler air in your home is drawn out and the warmer outside air is drawn in. This will happen even if there is only a couple of degrees difference between your indoor temperature and the temperature outside.

This is problematic because when you want to use your AC again, your AC unit needs to work harder to bring your home down to the desired temperature. On top of that, depending on the air quality outside, more energy is used to purify that air again so that clean, cooled air circulates through your home. You might not think it is a big deal for your AC unit to lower the temperature of your home by 1 to 3 degrees. The reality is that it is a significant expense if this is something you do every day over the course of the summer.

Possible Savings

It probably costs you around $1.24 to cool 1 square foot of your home each year. The amount will vary based on the construction of your house and how well it is insulated. The amount will also vary based on the number of people who live with you. According to the U.S. Department of Energy, you can save 1% for each degree when you adjust the thermostat for eight hours.

Shutting off your air conditioning unit at night reduces energy usage by around 30%. However, the extra energy needed to lower your home’s temperature after leaving your windows open all night means your air conditioning unit is working harder and is using up to 20% more energy. The savings you get from opening your windows at night and turning off the AC unit are minimal. This doesn’t factor in any humidity that might be present in the air, either.

How Humidity Affects AC Energy Expenditure

Have you ever heard the saying, “It’s not the heat, it’s the humidity”? This adage conveys the idea that humidity can make temperatures feel warmer than they are.

What you may not know is that this pertains equally to indoor and outdoor air temperature. If your air conditioning unit is battling against moisture in your home, the effects will impact your comfort level and the amount of money used on energy.

If there is high humidity in your home, you will have to set your thermostat at a lower temperature so that you feel comfortable. Each degree you lower your thermostat means a 3% increase in energy use. Over the long term, these small expenses add up.

During the evening in Las Vegas, the air can be very humid. The humidity will fill your home overnight and permeate your carpet and furniture. The next day your air conditioning unit is going to have to work harder to cool your home and remove the humidity that accumulated. Some studies suggest that leaving your windows open overnight means that your air conditioning unit will need to remove 5 extra gallons of moisture from your home so that it feels comfortable again.

The situation is even worse if your HVAC unit or air conditioner is poorly maintained. If you believe that your summer energy bills are higher than they should be, talk to the AC professionals at Polar Air & Heating, Inc.. We would be happy to look at your AC unit, recommend repairs or replacements, and help you feel comfortable in your Las Vegas home again.

When Sleeping With the Windows Open Could Save Energy


With all this being said, it can still be beneficial to swap your AC for an open window from time to time. First, you want to have fresh air cycling through your home occasionally. Second, opening your windows is advantageous if the nighttime outdoor temperature is significantly colder than your home’s indoor temperature.

You get the fresh outdoor air. You can cool your home and have a good night’s sleep. If you want to take advantage of the cool nighttime air, wake up before the sun starts to rise. Walk through your house, and close your windows and blinds. This will allow you to trap the cool air in your home. It won’t have to work as hard to cool your house when you start your AC unit because your indoor temperature will already be lower than usual.

Do You Actually Save Energy if You Open Your Windows?

No. At first glance, this seems reasonable. Your AC unit will keep your home cool and will be helped out by the cool breeze from outside. However, in the vast majority of cases, the temperature you set your thermostat for is cooler than the outside air.

Additionally, when Polar Air & Heating, Inc.’s professionals install an air conditioner, we first calculate the load necessary for the unit. This allows your home to be cooled efficiently. However, if you open a window, you increase the burden on your AC unit. You make your air conditioner work harder to maintain a set temperature because a lot of the air you cool is escaping out the window.

If you feel that opening your windows is necessary, turn off your HVAC system. When you are ready to use the AC, close your windows and turn the unit on. This will make it easier for your system to maintain a specific temperature and prevent your HVAC system from experiencing unnecessary wear and tear.

Benefit From Hiring Heating and Air Conditioning Professionals

At Polar Air & Heating, Inc., we have been offering premium heating and air conditioning services throughout Las Vegas and the surrounding area for several decades. The Mojave Desert area gets very hot during the summer months. It also has cold winters. You need an HVAC system that you can rely on. We are proud to be Better Business Bureau accredited and Energy Star certified.

We want our customers to experience the best in home comfort. We are proud to offer AC repairs, installation, and maintenance. We can also maintain, repair, or install a new furnace for you. We are meticulous about our craftsmanship, so we can produce excellent results every time. Are you ready to feel great in your home? Contact us at Polar Air & Heating, Inc. today to learn how!

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