In addition to the usual and expected results of not having a dehumidifier, I noticed today that there was condensation on the ductwork in the basement. Using my laser thermometer I found that the ducts were about 62 degrees, and that was with the AC cycled off. I put the indoor/outdoor thermometer in the basement since it gives a reading for indoor relative humidity and the answer was 77%.
Using a Dew Point Calculator (thank you, Rochester Institute of Technology!) I found that not only is the dew point 55 degrees, but it is putting the mechanicals and stored items in the basement at risk. A 55 degree Fahrenheit dew point means that you get condensation for temps above 55 degrees.
I guess I’ll be hunting up a dehumidifier ASAP, despite the sticker-shock I experienced a few days ago. Seemed to me that our old one, that was given to us by my sister-in-law, that worked at a rate of 70 pints per hour, cost about $100 plus tax. Today a similar one costs $250. Having found a dehumidifier calculator I think we can actually get by with one of the smallest sizes they sell but in a pinch I have been told I can exchange for a larger one if needed.