Home a/c systems – Why is it more efficient for it to run continuously a couple of hours rather than cycling on/off so often?

Question

For the sake of argument and discussion, let’s use a perfectly matched, balanced, and calibrated R-410a home a/c system as an example.

Why do folks say it’s more efficient for said home a/c system to run continuously for 2 hours and then off for 5 minutes instead of cycling on/off much more often to achieve the same interior cooling setting on the thermostat? (I understand how home a/c system work, but I’d like to know why some say longer run times = greater efficiency.)

I’ve heard this claim time and again, but I’d like to know the science behind it. I live in Texas where a/c units run for hours during the day from June through September.

In: Engineering

Answer 1

It takes more energy to get things moving, then it does to keep things moving.

There is also an energy cost to getting the refrigerant to ideal temperature, So if it cools down or heats up that process must be done again