70% humidity at 72 degrees with my Trane XL15i and Hyperion- why so humid?

[clydesdale]

I have a 2 ton system for my upstairs 1100 sqft condo. It usually keeps the humidity around 50-54%. But it was over 90 here today and I am sure it ran for most of the day. Any idea why it is so humid? It feels fine, but I just checked it out of curiosity at the thermostat and it seems pretty high. THanks

[vstech]

tight construction can lead to high humidity... as can low loads. a condo could have low loads due to adjacent homes temps...
also, you could have humidity entering from long fan run times, or dryer usage... cooking loads, extra guests etc...

[teddy bear]

Fan in the "auto" mode or "on"? During high cooling loads, the a/c should be able to maintain <50%RH. A/c needing surface could be. What is the temp/%RH of the supply air to the space?
Regards TB

[clydesdale]

Teddy bear, I thought the supply air is the air in the house. THe outside air is 80 degrees with 77% humidity. Inside is 72 with 70% humidity. The fan is on auto.

[teddy bear]

Supply is the air entering the home from the a/c.
Temp/%RH? Sounds like the system is slowly losing capacity.
Regard TB

[beenthere]

The supply air, is the air blowing out of the registers.

Thermostat's humidity sensor may be off. 70%RH at 72 would feel very uncomfortable.

[clydesdale]

When I woke up this morning it was still 72 degrees, but 51% humidity. Please explain. Thanks.

[beenthere]

Get another hydrotherm, and place it near your thermostat.