you know, to be honest, i have never really tested them...i just know that the newer one is energy effecient. and, i too, like and need a dry basement - my laundry room is down there, there is a tv, a wii, a couch and a playroom that gets used! so, i just run them both. the nonenergy effecient one runs while on the laundry side of the basement pretty much from about 7a - 10p. the energy effecient one which is in the other playroom, runs about the same amount of time. no choice and not going to test what happens if i cut the time down.