I am currently working on a strategy for a dehumidification system for the Appleseed House in Minneapolis, MN. There are a few weeks out of any given year that make dehumidification a necessity. Most Minnesotans agree that the humidity is what makes July and August unpleasant, rather than the temperature. During the Passive House Consultant’s training I was able to spend some time with David White from Transsolar on the subject. We identified one strategy that uses a Thermastor UA-XT150H dehumidification machine (see image) that can be added to the airflow at those times of the year. In further discussion with Thermastor I learned that I actually have options on how to use their equipment. The original idea that David and I discussed was to utilize a ground-loop to run a water-cooled coil in the Thermastor machine. In this case, heat generated in the process would be deposited in the ground. A way to put that energy to better use would be to run a loop through a DHW storage tank. Alternatively, the machine could be run without the condensing coil inside, and simply exhaust to the exterior. Further investigation is needed to make the proper choice. I also learned from Thermastor that the machine David and I were looking at is likely oversized. Thermastor does offer smaller capacity units that may be more fitting for my particular application. The water-cooled coil is a special order version of the XT150H.