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
This is why modern units with variable speed compressors are good. Instead of having one massive startup spike (that’s also why window and portable units will sometimes cause lights to dim when they kick on), it can run the compressor at a large range of speeds. So instead of turning on full tilt to cool and then shut completely off, it can run let’s say 25-50% constantly to maintain temp, and then dip to 10% power when there is less demand for cool. By having a variable speed compressor you are averaging out the power draw, running in a more efficient manner as far as cooling and dehumidifying, and you’re putting less stress on the electrical systems both in your unit and the grid.
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