Here are some sources where you can do a little research.
NOTE: If you want to take a short cut to the bottom line you might just go to
Is a great place to start. Go down the left side of the page and click on "links and resources", or copy the line below into your browser:
is one of the links on the resource page of EcoBroker It has lots of highly technical stuff that the HVAC guys use.
Be sure to visit the US Department of Energy (DOE) and EPA links.
Learn about Energy Star (SEE BELOW)
If you drill down far enough you will come to this page:
This last page is probably the one you want to GO TO FIRST if you want to read about a wide range of ways that you can save energy without necessarily installing a new HVAC system.
Hope this helps. Be warned; it will take you most of the rest of your lifetime to search through all this material if you follow all the bunny trails that you could follow just starting with the EcoBroker site.
:) Have fun!
Eileen's Green Team