ONE OF HUMANKIND'S greatest accomplishments —after the splitfinger fastball and the NCAA's March Madness, of course—is the ability to control our indoor climate. Appropriately enough, air conditioning a house is also the costliest part of operating it, which is why there is always an ongoing effort to make the process more energy efficient.

In an attempt to do just that, the federal government, in its infinite wisdom, has raised the minimum energy-efficiency standard for HVAC units as a way to help consumers save money. On Jan. 23, 2006, the minimum rating will jump from 10 SEER to 13 SEER, a 30 percent increase. The DOE says a 13 SEER rating will save 4.2 quadrillion BTUs between 2006 and 2030— an amount that is the equivalent of the annual energy use of 26 million U.S. households. This will also save consumers money on each monthly utility bill, which should total a cool $1 billion by 2020. The new standard only applies to equipment manufactured on or after Jan. 23, 2006, so if you've already purchased old units, use them if you've got them.