Set it and forget it

Here’s something a lot of people don’t realize. The warmer you keep your house in the winter, the faster it loses heat. That’s not my opinion, folks. That’s basic physics.

And here’s something else worth understanding. It’s not really about warm air or cold air. It’s about heat energy. Cold isn’t something that creeps into your house. Cold simply means there’s less thermal energy.

In the winter, your house is constantly losing heat energy through the walls, windows, roof, and floors to the colder outdoors, and your heating system is working to replace it. And here’s the interesting part. Even if your house were perfectly sealed, with absolutely no air leaking in or out, it would still lose heat. That’s because heat can travel through solid materials. Stopping air leaks helps, but it doesn’t stop heat transfer.

Think of it almost like dipping the corner of a dry paper napkin into water. Watch how that water naturally travels up through the napkin. That’s called capillary action. Now, heat doesn’t move by the same physical process, but the comparison helps explain the idea. Just as the water spreads through the napkin, heat naturally transfers from warmer areas to cooler areas. And the greater the temperature difference, the faster that heat transfers.

Now think about your house.

If it’s 20 degrees outside and you keep your thermostat at 70, that’s a 50-degree difference. Lower that thermostat to 66, like we do, and the difference drops to 46 degrees. That’s approximately 8% less heat loss through your house under the same conditions, simply by keeping it four degrees cooler.

Pretty interesting when you think about it.

Now here’s something else I’ve noticed over the years. A house that’s maintained at 66 degrees can actually feel warmer than a house that’s just been heated back up to 66 degrees after being turned down overnight.

Why? Because you’re not just heating the air. You’re heating everything inside the house, including the walls, floors, furniture, and ceilings.

When you maintain a steady 66 degrees, those interior surfaces tend to stay close to that temperature. But if you turn your thermostat down to 60 overnight, those surfaces gradually cool off, too. They might not all reach 60 degrees by morning, but they can be noticeably cooler.

Then you wake up, crank the thermostat back to 66, and wonder why the house still feels chilly even though the thermostat says 66.

Well, there’s your answer! The air might be 66 degrees, but the walls, floors, and furniture are still catching up. Your body loses heat to those cooler surfaces through radiation, making you feel colder even though the thermostat says otherwise.

That’s why maintaining a steady temperature can make a house feel more comfortable without having to turn the thermostat higher.

Now here’s where things get even more interesting, especially for those of you who have heat pumps.

Unlike an oil or gas furnace that produces heat by burning fuel, a heat pump actually moves heat energy from the outside air into your house. And believe it or not, even when it’s freezing outside, there’s still heat energy available for a heat pump to extract.

Heat pumps generally operate efficiently when maintaining a steady indoor temperature rather than constantly playing catch-up.

And something a lot of homeowners don’t realize is that on many heat pump systems, walking over to the thermostat and raising it just 2 or 3 degrees can actually trigger the backup heating system. Depending on your setup, that could mean expensive electric resistance heat or an oil furnace kicking on when the heat pump might have been able to handle the job by itself.

So much for saving money!

That’s why I’ve always been a believer in set it and forget it!

We keep our house at 66 degrees all winter long. No turning it up in the morning, down at night, and back up again. Just find a comfortable temperature and leave the darn thing alone.

Now, don’t get me wrong. Lowering your thermostat for an extended period can absolutely save energy. That’s basic physics, too. But with heat pumps, particularly those with expensive backup heating, the energy used to recover from those temperature setbacks can sometimes eat into the savings.

And remember, the cooler you keep your house, within reason, the less heat your heating system has to replace. You’re not just saving energy by making the equipment work more efficiently. You’re actually reducing the amount of heat your house loses in the first place.

So before you go spending thousands of dollars on a more efficient heating system, it might be worth understanding a little science behind how heat actually works.

Keep your thermostat at a reasonable temperature, stop fiddling with it all day long, and let your heating system do its job.

Sometimes saving money is as simple as understanding a little physics.