I recently read a paper called, Do Heat Pump Clothes Dryers Make Sense for the US Market? To my dismay the study found that heat pump clothes dryers (HPCD) don't make economic sense unless you do over 700 dryer loads a year. The problem that HPCDs run into is similar to the problem that hybrid cars have. Namely, high upfront costs aren't justified by lower operating costs unless you operate a lot.
But maybe... What if you used the HPCD as an auxilary space heater when it wasn't doing the laundry? If you were like me and could use the heat pump heating to offset resistance heating you could quickly save a pile on your heating bills. I've been golluming a heat pump space heater for years but I don't really have the room for one. I googled high and low but I couldn't find an example of an appliance company like Bosch, GE or Whirlpool working on something like this. I thought WTF... Do I have a gross conceptual error (GCE) or something?
So I started writing letters... Dear Bosch... Dear LBNL... Dear DOE... Dear Energy Nerd.... Dear Top Ten... I really wrote five letters. In the end one of the authors of the original paper I mentioned got back to me. After some back and forth Mr. X agreed that given the right configuration (see picture) the idea of using a HPCD as an auxilary heater would work. He added that this sort of venting configuration is being considered with heat pump water heaters as well. So there you have it.