The Dehumidification Limits of Mini Splits during Summers

Published on June 11, 2025

Why Supplemental Dehumidification Is a Necessity

Mini split heat pumps have become a popular choice for residential and light commercial cooling and heating due to their energy efficiency, ease of installation, and zoned temperature control. However, one common complaint from many users, especially during New York summer months, is that “My mini split isn’t dehumidifying enough.”

This blog delves into why mini splits lacks the ability to dehumidify during summer, the consequences of insufficient humidity control, and why you should consider adding a supplemental dehumidifier.

How Do Mini Splits Cool and Dehumidify?

Mini splits cool the air by drawing warm indoor air across a cold evaporator coil, where moisture in the air condenses and drains away. This process helps reduce humidity while cooling. It’s like having a tiny dehumidifier in the system. 

But in practice, the system’s ability to remove moisture is limited and during hot and humid seasons, that limitation becomes apparent.

Why Mini Splits Often Don’t Dehumidify Well in Summer

1.    Higher Temperature Setpoints: Most New Yorkers set their systems to maintain comfort around 75–78°F. At these levels, the coils aren’t cold enough to condense large amounts of moisture.

2.    Inverter Compressors Reduce Coil Run Time: Mini splits often run at low capacity to save energy, which results in higher coil temperatures and less condensation.

3.    Limited or No Dedicated Dehumidification Mode: There are many systems that don’t include a true dehumidify cycle dry mode, which limits performance.

4.    Short Cycling in Zoned Systems: The system reaches a set temperature quickly and shuts off when only small areas are cooled. This means shorter run times and limited dehumidification.

What Is Dry Mode on Mini Splits?

Mini-split systems often come with a dry mode which is intended to reduce humidity. However, these settings are very basic and offer options like HIGH, LOW, or STANDARD. While dry mode can help reduce some humidity during warmer months, it is not a substitute for a dedicated dehumidifier. Dehumidification should operate independently of your HVAC system to ensure year-round moisture control.

Differences Between Mini-Split Dry Mode and a Dehumidifier

If you’re wondering whether dry mode is enough or whether you need a dehumidifier, here’s how they compare:

FACT: Supplemental Dehumidification Independent of HVAC System Is a Necessity to Remove Moisture Trapped Indoors

If your goal is optimal indoor comfort and protection from mold, mildew, and moisture damage, you’ll need a dedicated solution. Mini splits cannot match the precision and performance of a standalone dehumidifier when it comes to keeping indoor humidity below 60%.

How MR. AIR NYC Ensures Proper Sizing for Better Dehumidification

We don’t believe in one-size-fits-all solutions. Every home and space we work with undergoes a Manual J load calculation, an industry-standard process that factors in square footage, insulation, window types, and more to determine the right system size.

This is essential because an oversized system may cool the room quickly but won’t run long enough to pull out sufficient moisture, leading to lingering humidity. By properly sizing your mini split, we ensure optimal run time, better humidity control, and improved year-round comfort.

If you’re considering a Mitsubishi mini split or need help with excess humidity, MR. AIR NYC offers trusted expertise and tailored solutions across New York City (Manhattan), Brooklyn, and Queens.