Is It Better To Oversize Or Undersize A Mini Split?

Choosing the appropriate size for a ductless mini split system has proven more difficult than you thought.

Is it okay if your mini split is a bit oversized or is it better to undersize it?

If you can’t buy a mini split that’s the appropriate size, a slightly oversized mini split is better than one that’s too small. Let’s explain why.

When you undersize your mini split, you limit its capacity. This hinders how much heating and cooling the unit can provide right out of the gate, which can leave you wanting more.

Once your undersized mini split is hooked up and operational, it works harder to provide any meaningful heating and cooling.

Again, the lack of efficiency can make you think you made a mistake choosing a mini split over standard HVAC when really, it’s that you went too small.

An oversized mini split has more than enough power. While you may wonder what this means from an energy efficiency standpoint, it’s not as bad as you might imagine.  

Think of your oversized mini split as your TV volume. You know you could crank it all the way up, but you never do, right?

An oversized mini split could operate at full power, but there’s no need, so it doesn’t. It simply uses the power required to heat or cool your home. The rest of the standby power is good to have.

So let’s say you’re in a situation where you can buy a 2.5-ton or three-ton mini split. If you truly don’t know which would be better, choose the three-ton mini split.

After all, it’s difficult to calculate your exact heating and cooling loads, and the extra bit of leeway gives you peace of mind that you’ve not undersized your mini split.

Here’s another great reason to slightly oversize your mini split: temperature extremes.

It’s no secret that hot summers have gotten even hotter and cold winters even colder. A mini split that can run at a higher capacity than what you’re currently using will safeguard you against these extremes.

The key though is to oversize the mini split only slightly. If your home only needs a 2.5-ton mini split and you buy a five-ton mini split, you’re no longer making an advantageous decision.

The mini split might pull too much power, causing an outage throughout the entire house. If you can get the power back on and stabilized, you’ll realize that an oversized mini split is prone to overheating.

If it overheats and fails, you have no heating or cooling until you can get the mini split back up again. That often requires calling your mini split technician to repair the unit. Doing that often enough can get very expensive!

Start your search for the right mini split for your home at PowerSave AC. Our selection of mini splits includes single-zone and multi-zone units for just the right level of heating and cooling.