JESS: Question on the Fuzzy control using Jess

[David]

Hi guys,   I understand this area has been posted a few times. I am following the materials in the book (JIA) especially the example on HVAC and always have the urge to test and run the simulations myself.   When I run the fuzzy version of the HVAC controller in the book, I realize the heat pump is on most of the time. A plot of the graph reveals that the pump is in operation 99.8% of the time. On the other hand, the Boolean logic version of the controller is in operation  about <90%.   I understand the algorithms implemented are not meant to be optimal as this is not a book on control engineering. However, based on the two observations I have two questions.   Am I doing the right thing ? Is the Fuzzy version of the controller suppose to be in operation close to 99.8% of the time? I wonder if there is a way to make the fuzzy version to be actually more energy efficient (i.e. operation times to be lower than the Boolean version, yet without switching the pump from OFF mode to operation mode too frequently)? I read in some books and websites that fuzzy logic sometimes do help to cut energy cost. Any ideas how this can be done ?     I wonder if anyone has tweak around with the example in the book before. Would appreciate any comments and ideas. Many thanks!!   Regards, David