Definition
Latent load is the part of a home's cooling load that comes from moisture in the air rather than temperature, measured in BTU per hour. An air conditioner handles it by condensing water vapor on the evaporator coil. Sensible load is the temperature part, and an ACCA Manual J calculation estimates both to size equipment.
Also called: Latent heat load, Moisture load
Why it matters to you.
Humid Central Kentucky summers put a large latent load on air conditioners, which is why a house can read 74 degrees and still feel sticky. Oversized equipment cools the air quickly and shuts off before removing much moisture, while low airflow or a dirty coil can leave indoor humidity high even on long run times.
Practical guidance.
If your home feels clammy, note the thermostat setting, run times and a hygrometer reading before calling. For a replacement, ask whether the Manual J calculation accounts for latent load and how the proposed equipment and blower settings handle moisture removal.
About this definition
Written by the Feistritzer Heating & Air Conditioning team — family owned and operated in Danville since 1976, Kentucky HVAC license M02584. Definitions inform; a whole-system diagnosis in your home decides.