Dehumidifier needs: Minotair vs whole house dehumidifier
Hi, I just posted asking for opinions about the Minotair Pentacare V12. I have made several estimates/guesses that I think are correct…but maybe not?
At 25 C (~70 degrees F), about 10 grams of water needs to be removed from 1 kg of air at 100% RH to reduce it isothermally to 50% RH. Assume 25,000 cubic feet of conditioned space (actually larger than I plan but probably typical). I will aim for 1 air exchange per hour at 50 Pa or better. Assume then 0.1 ACH at normal conditions. Unit conversions lead to, I think, 44 pints water removal per day. Let’s say 50 pints to account for mammalian insensible water loss (3 people, 1 dog). Man I hate using different units all the time!
The AprilAire 1870 whole house ducted dehumidifier is rated at 130 pints per day (80 degrees F and 60 % RH). The manufacturer claims it will remove 2.7 L water per kWh energy expenditure at standard test conditions (IEF, or Integrated Energy Factor). Therefore 50 pints cost ~ 9 kWh.
The Minotair capacity is comparable, 118 pints per day. They do not report an IEF, but they do report maximum power usage of fan (136 watts) and compressor (725 watts). Assume typical operation at 50% of maximum power usage (reasonable ?), then the Minotair uses about 10 kWh, very comparable to the dedicated dehumidifier. Plus, the Minotair provides all ventilation needs, and supplies about 11k BTU/h cooling (probably all I’ll need on hotter days), and 8.7 k BTU/h heat at 47 degrees F with a COP of 3.0…probably most if not all I’ll need from late spring to mid fall. Costs a lot more than a stand-alone dehumidifier, but I really don’t see any downside to this for my needs.
Any thoughts? Am I way off in my calculations? Thank you everyone for making this a really informative and fun website!