Understanding High Humidity in DX Systems

In this video

A cooling coil only removes moisture while it runs cold and wet. Oversized, cycling equipment satisfies temperature fast and shuts off, so the coil spends little time actually dehumidifying — and moisture left on the coil re-evaporates into the space during the off-cycle. Extending run-time through modulation keeps the coil removing moisture.

Key takeaways

• A coil dehumidifies only while it runs cold and wet
• Short cycles remove little latent moisture; off-cycle re-evaporation adds it back
• Longer run-time is the lever for humidity control
• APR Control extends run-time to keep the coil dehumidifying