Check the age of your current heating and/or air conditioning unit. Generally, newer products are much more efficient that older products. Current furnaces on the market can be over 90% efficient. Modern air conditioners also use much less electricity than their predecessors.

Before making an air conditioner purchase, be sure to check the "SEER" or Seasonal Energy Efficiency Ratio on the product you are considering. This efficiency measurement is similar to Miles Per Gallon for cars. The higher this number, the more energy efficient they system is. New units have SEER ratings from 13 to 21. Generally, purchase price increases with SEER.

When selecting a furnace or heating unit, check the efficiency rating. Heating systems with efficiencies in the 90% range are best, but for less money, you may want to go with an 80% efficient.