Can You Oversize a Mini Split?

Ductless mini split systems provide heating or cooling by room, also known as zones. Since your mini split system can include as many as five zones, sometimes even more, you may wonder if it’s possible to have too many mini splits through oversizing.

In today’s post, we’re here to explore that very topic so you can make a smart, energy-efficient choice for your home or office.

Can You Oversize a Mini Split?

Some mini split systems might not be as hulking as the furnace in your basement or the air conditioning unit in the backyard. This may give consumers the impression that you can’t oversize a mini split system.

As it turns out, that’s very much not the case. Mini splits can indeed be oversized. If you’re of the bigger is always better mentality, then you may wonder how this could be problematic.

To answer that question, we’ll look at an example. Let’s say you decided to get an oversized mini split, which will come with a large compressor. Within the compressor are coils. Yes, these are larger coils than average. The upside of the coil size is their increase in efficiency, so it’s not all bad. That said, you only get this efficiency if the compressor speeds are low and the coils run nearly constantly.

Also, since the coils are considerably more sizable, they need bigger blowers to match. These prevent overheating. You’ll also burn through a lot more refrigerant, as big coils call for equally big quantities of refrigerant.

The size of the blowers also work against you in ways. The larger coils of the compressor combined with the equally large blowers increase start-up ramp energy use. That means each time your mini split turns off or on, the compressor is not nearly as proficient as it would be if it were smaller. The same is true when the unit is running at levels of minimum modulation.

How to Choose the Correct Sizing for Your Mini Split

Okay, so you know to stay away from oversized mini split systems, as these may be too much of a good thing. Instead of just assuming you need the biggest mini split automatically, why not calculate the size of the rooms of your home or office in square feet? Then you can use this chart to determine how much heating or cooling you require.

  • 150 to 300 square feet: 6,000 BTUs
  • 300 to 650 square feet: 12,000 BTUs
  • 650 to 1,000 square feet: 18,000 BTUs
  • 1,000 to 1,350 square feet: 24,000 BTUs
  • 1,350 to 1,650 square feet: 30,000 BTUs
  • 1,650 to 2,000 square feet: 36,000 BTUs
  • 2,000 to 2,300 square feet: 42,000 BTUs
  • 2,300 to 2,650 square feet: 48,000 BTUs
  • 2,650 to 3,100 square feet: 56,000 BTUs

Now, the above are estimates and not necessarily set in stone. If you have questions about the exact amount of heating or cooling you need in BTUs, we recommend you get in touch with your mini split technicians at PowerSave AC. We’re here for all your mini split needs and questions, so call us today!