Derek ColeGM, Simmons One Hour Heating & Air · AI HVAC Answers

AC Running Long: Efficiency vs. Short Cycles #shorts

21 Jul 2026 · 1 min

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0:52

In this YouTube short, HVAC professional Derek Cole explains why an air‑conditioner that runs for a longer, continuous period is often more efficient than one that cycles on and off frequently. He uses a hot‑day scenario (≈98‑100°F) to illustrate that, just as a driver rarely turns off a car’s AC on a scorching day, a home’s AC will stay on to maintain its thermostat set‑point. Once the set‑point is reached the unit will shut off, but if the system is properly sized, the continuous run is preferable because it avoids the energy penalty of repeated start‑ups and shutdowns. The key message is that a correctly sized unit operating for an extended stretch is more efficient than short, frequent cycles.

Chapters

You don't want it to stop running. I mean, think about when it's 98, 100 degrees outside. Think about getting in your car and then driving to the store. How many times did you turn off the AC? Probably not ever. Your home's the same way. It's trying to keep that same temperature all throughout the day, so it's not going to stop running if it's on a set point it's trying to reach. Now, if it reaches that set point, then obviously it's going to turn off, but the unit running for a long period of time is not necessarily a bad thing. If the unit is sized— to go back to the first question— if it's sized properly, it is running— it is better for it to run longer because it's more efficient than turning on, turning off, turning on, turning off.