~so then I use the sets in the basement where I can open a window and exchange the air in that one room only, saving the conditioned air.
Sounds like a sense of false economy to me.
Dried cooled air as sucked in from an air-condtioned room will help the dryer funciton faster amd therefore overall, with less energy (used by the dryer). So it's six of one and half-a-dozen of the other.
Air-cooled condenser dryers release a great deal of heat into the room. Water-cooled condenser dryers of course use water that one may not want to use, if avoidable.
1- The electric dryer you have now can be vented into the house in winter, if you do one load every few days; otherwise the humidity may cause mold and mildew problems. Use a pair of pantyhose over the outlet to catch lint.
2- The heat released into the basement in summer WILL creep up into your living space.
3- Condenser dryers use much more energy than vented ones and cool-downs and anti-wrinkle settings take literally hours. They tend to have small capacities and heat very slowy...based on what we are used to. Don't even bother with a Euro dryer unless you have a Euro washer-- without super fast spins the dryer will simply not perform to your expectations.
Bottom line, in my ridiculous opinion, get a condenser dryer because they are fun, maybe not becuase they are practical.