Nobody wants to heat or cool an empty home, so what temperature should you set the thermostat to when you are away? Unfortunately, there isn’t a “one size fits all” answer to this. What temperature you set the thermostat to while you’re away depends on a range of factors such as how long you’ll be out of the house and the climate where you live.
What temperature should I set my thermostat to when I’m away? As a general rule, set your cooling at 5 to 10 degrees higher than usual so your home is warmer before the cooling kicks in. It will also turn off more quickly. Decrease the temperature setting on your heating by 10 to 15 degrees so it will wait longer before kicking in and turn off more quickly.
However, before you go ahead and begin changing your thermostat settings, there are a few things you need to consider.
How Long Will You Be Away?
If you are going to be away from home for a couple of hours, there’ll be no benefit in changing the temperature on your thermostat. Not only will the fuel cost savings be negligible, but you may even end up raising your bills.
How might you spend more by changing your thermostat settings for a few hours?
When your heating or cooling is set to a specific setting, the system doesn’t have to work too hard to maintain the temperature. However, if your system has to heat or cool your home by several degrees, it must work harder and use more fuel.
It is the same principle as fuel use when you drive. Lots of stop-start journeys around town, where you have to accelerate up to speed and then slow down again, uses more fuel than a steady cruise along the highway.
So, if “stop-start” heating and cooling is not a good thing for your system or your wallet, how long should you be away from home before you adjust your home’s temperature?
If You Are Away From Home For Eight Hours Or Less
If you will be away from home for seven hours or less, there is no real benefit to changing your temperature settings.
If You Are Away From Home For More Than Eight Hours
Once you cross the eight hours away threshold, it can become worthwhile to change your thermostat settings.
What Temperature Should You Set Your Thermostat To When You’re Away?
Suppose you are going to be away in the summer. In that case, you have air conditioning, and you want to come home to a comfortable home, you should raise the setting on your thermostat so your air conditioning will wait longer and kick in at a higher temperature than it usually would.
The ideal increase is somewhere between five and ten degrees higher than usual.
For time away from home in the winter, the opposite is true. Consider your average comfortable temperature and lower the setting on your thermostat so the heating will wait longer before starting up and turn off sooner than it usually would.
The ideal decrease is at some point between 10 and 15 degrees higher than usual.
How Do You Choose Your Exact “Away Temperature?”
The exact changes to your air conditioning and/or heating settings will depend on a number of variables. Therefore it is important to consider the following factors when choosing your “away settings.”
1. What Temperature Do You Find Comfortable?
One person’s comfortable temperature can be another person’s freezing or sweltering.
So.
Rather than thinking about setting your thermostat to a specific temperature, think of it in terms of “what temperature do you usually like your home to be?”
Once you establish which temperature you find comfortable, you can decide what will be the best “away setting” for your home and your family.
2. What Sort Of Local Climate Do You Have?
Suppose you live in a place where the climate is relatively steady. There isn’t too much of a difference between the daytime and the over-night temperatures, and there aren’t sudden changes in the weather.
If you live in a climate with relatively steady temperatures, it is much easier to establish your “away” thermostat settings.
In a relatively steady climate, you can set your cooling to ten degrees higher than usual and your heating to 15 degrees lower than usual.
On the other hand, if you live somewhere that experiences significant differences, either between daytime and overnight temperatures or through sudden swings in the weather, it can be more challenging to decide which settings to use.
In a climate that experiences larger swings in temperature, set your cooling to five degrees higher than usual and your heating to ten degrees lower than usual.
3. Will There Be Pets In Your Home While You’re Away?
If your pets are at home while you are away, consider their health and comfort. A good option is to speak with your veterinarian, explain how long you will be out of the house, whether or not someone will be coming in to care for your pet, and ask for their advice.
Why Turning Your Heating And Cooling Off Entirely Is A Bad Idea
Some homeowners simply turn their heating, ventilation, and air conditioning (HVAC) off entirely while they are away, but this can be a bad idea.
Why?
Turning Off Your HVAC Can Cause Damage
Extremes of temperature can cause damage to your home.
If The Temperature Drops Too Low
In colder climates, turning off your heating entirely while you are away can lead to frozen pipes.
Your plumbing has a certain amount of water in the pipes at all times. When temperatures drop low enough, this water can freeze. Frozen water takes up more space than liquid water. As the water begins to freeze, it fills all of the available space, and if there is not enough room, the pressure of the ice can cause joints to fail and pipes to crack.
You may not know this has happened until your home warms up again, the ice begins to melt, and water pours from the cracked or burst pipes.
If The Temperature Rises Too High
Turning off your cooling can cause a build-up of heat and humidity in your home in hotter climates.
In higher humidity, wooden floors can expand and buckle, sometimes causing permanent damage. The heat will also build up in your roof space, which can cause swelling and buckling in your roof structure and shingles.
In addition, an increase in humidity can cause mold and mildew to form in your home’s structure, such as on the sheetrock or the substructure of the floor, and this can be difficult to eradicate. Mold and mildew can also form on your belongings.
Turning Off Your HVAC Can Cost More
If you are only away from home for a short period, and the temperature is likely to change significantly in your home while you are away, turning off your HVAC can cost more than leaving it on.
This is because your HVAC will have to work harder to either heat up or cool down your home by a large amount than it would to hold a steady temperature.
As a result, turning off your HVAC completely, then turning it back on when you return can use more energy, costing you more than lif you left it on.
Consider A New Thermostat
Today’s new smart thermostats can make setting the temperature when you are away a lot easier. Not only can you program multiple settings, for example, different temperatures for the day during the week when you are at work and the weekend when you are home, but you can also monitor and control your home’s climate from your smart device.
I particularly like the ecoBee thermostat, which works with Alexa, and the Google NEST.
Final Thoughts
As a general rule of thumb:
- For air conditioning, set your thermostat to a temperature of between eight and ten degrees higher than your usual setting.
- For heating, set your thermostat to a temperature that is between 10 and 15 degrees lower than your usual setting.
The exact temperature you set your HVAC to while you’re away will depend on your personal temperature preferences, the climate where you live, and how long you will be away.
And a quick question before you go: Whereabouts in the country are you, and what temperature do you have your thermostat set to right now? I’d be interested to know what you consider to be a comfortable temperature in your home.