Do I turn the heat off when im not home?
Should You Turn Off Your A/C When You’re Not Home? Here's What Happens
Hot summer days — yeah, we all know the drill. The sun’s out, your electricity bill’s creeping up like a bad habit, and you're left wondering: Do I leave the A/C blasting all day, or do I let the place cook while I’m out and hope it doesn’t feel like a sauna when I get back?
You’re not alone in this dilemma. People argue about it like it’s a religious debate, but here’s the thing — the truth is buried somewhere between "turning it off saves energy" and "just leave it on, you’re gonna fry otherwise." So, we dove into the numbers. A crew of engineers took a hard look at the science, and here's what they found.
Let the House Heat Up Like a Pizza Oven, or Keep it Cool?
Let’s talk about how heat really works. It’s not some evil force lurking in your walls. Heat loves to invade your home when it gets a chance. Think of it like this: if your house was a beer cooler, heat would be the drunk guy who refuses to leave.
If you turn the A/C off while you're gone, your house is going to warm up. It’ll sit there, stewing in the sun, baking in the heat, and by the time you walk back in, it’s basically a dry sauna. Now, if you’re wondering whether it’s more efficient to just let it stew and blast the A/C once you get home, the answer isn’t as simple as you'd think.
Here’s the thing: If you leave your A/C on, it’s going to run constantly, fighting that heat at a steady pace. But if you let it sit there, letting the heat accumulate while you’re gone, you’re going to have a big mess to clean up later. If your house can only hold so much heat — say, five units of thermal energy — that’s all you’ll need to remove when you get back. But the longer you wait, the harder your A/C has to work to undo the damage.
And here’s the kicker: Your A/C works less efficiently when it's hotter than hell outside. So, turning it off during peak heat hours might actually save you a bit of energy — but it depends on how much heat your house can hold before it hits equilibrium with the outdoors. And, unfortunately, there’s no simple answer to this. Sorry.
The Energy Playbook: Which Strategy Saves You More?
Let’s run a little test here. Picture your house as a 1,200-square-foot box of misery, sitting in the desert sun of Arizona or the thick, suffocating humidity of Georgia. You’re staring at three options:
Keep the temperature locked in at a steady 76°F (24°C).
Let it climb to a sticky 89°F (31.6°C) for eight hours — this is what we call the “setback” strategy.
Let it reach that same 89°F (31.6°C), but for just four hours, because, you know, you’ve got things to do.
Now, imagine three types of A/C systems battling it out:
The typical central A/C (basically your standard-issue machine).
The fancy central air source heat pump (ASHP) — more efficient, but a bit of a pricey upgrade.
The mini-split heat pump — a little like the hipster of the A/C world, super efficient but also a bit extra.
We crunched the numbers for these three scenarios in two very different climates: the dry heat of Arizona and the swampy mess of Georgia. No matter what type of A/C you’ve got, the energy spikes when your thermostat tries to get your place back to 76°F. But here’s the kicker: The “setback” strategy still saves energy in the long run — and we’re talking up to 11% over the course of a year, especially if you’ve got a standard A/C.
The Catch: Better Insulation or a Newer A/C? Might Be a Wash
So what does this all mean for you? If your house is better insulated or your A/C system is newer and more efficient, the savings from turning off the A/C while you’re out might not be as dramatic. But here’s where it gets interesting: Even if you’ve got the best setup, cooling a place down after it’s been baking in the heat still uses less energy than running the A/C all day long, fighting the sun and humidity from the get-go.
The takeaway? If you’re willing to let the house heat up a bit during the day, your system will have less work to do when you return. If you’re rocking an old-school A/C system, this will probably save you some serious dough. But if you've got a modern heat pump, don’t expect miracles — the energy savings are there, but they’re more subtle.
Final Thoughts
So, should you turn off the A/C while you're out? In short: Maybe. It depends on your home, your system, and whether you’re willing to live with a bit of heat buildup in exchange for a little more money in your pocket. Like most things in life, it’s a trade-off. Do you want comfort all day, or do you want to save a bit of cash and deal with the heat when you get back? Either way, remember: Your A/C doesn’t care about your schedule — it just wants to run. You, however, should be the one in charge.