The Perfect HVAC has the following attributes:
-It is effective at achieving and maintaining the desired air temperature and humidity level regardless of outdoor conditions or internal loads.
-It is energy efficient.
-It can be installed and repaired easily.
-Mechanical components have a lifespan of 20 years or more.
-It is compact.
-It is quiet.
-It is affordable.
-It is unobtrusive.
As far as towers of ilium is aware, it does not yet exist. The modern heat pumps are getting close, but they aren't there yet.