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Translating The Ratings

I am trying to live as efficiently as possible to save money and the environment. There seem to be so many different efficiency ratings. How can I evaluate which appliances are the most efficient?—Bob M.

Using the most efficient appliances and products can significantly cut your utility bills.

When comparing the efficiency of products for your home, it often takes a calculator to determine the most efficient. The wattage rating listed on the label indicates how fast it uses electricity.

Luckily, government and manufacturers’ associations have made it easier to compare the highest-energy-use items.

Heating and cooling are the greatest consumers of energy in most homes. All furnaces, heat pumps, and central air conditioners will have one of the efficiency ratings discussed below. A higher number indicates higher efficiency. Keep in mind, more efficient models usually cost more initially, so have the contractor do a payback analysis for your home.

HSPF (heating seasonal performance factor)—this is a heating efficiency rating that compares the seasonal electricity use of heat pumps.

SEER (seasonal energy efficiency ratio)—this is a cooling efficiency rating that compares the seasonal electricity use of heat pumps or central air conditioners.

Heat pumps and central air conditioners are unique appliances in that, as the outdoor temperature changes, so do their efficiencies. This is because a heat pump, which is basically a central air conditioner running in reverse during the winter, must draw its heat energy from outdoors.

This is easy to do when it is 50 degrees outdoors, so the heat pump operates very efficiently. When the outdoor temperature drops to 10 degrees, the efficiency and heat output of the heat pump drop substantially. There are also inefficiencies when the heat pump starts and stops, and the HSPF and SEER take this into account.

EER (energy efficiency ratio)—this is the cooling efficiency rating that compares the electricity use for window and portable air conditioners. It is a less accurate comparison than SEER because it uses just a steady-state (highest efficiency) operation.

AFUE (annual fuel utilization efficiency)—this is the heating efficiency rating that compares the fuel use of natural gas, propane, and oil furnaces.

Water heater efficiency can be compared by its EF (energy factor). Water heaters also have a yellow Energy Guide label on the tank that lists the estimated annual operating cost. You can also use the yellow energy label to compare refrigerator/freezer and clothes washer efficiencies.

Visit the Association of Appliance & Equipment Manufacturers Web site ( to find efficiency ratings and output capacities of these heating appliances. Efficiency ratings of heat pumps and air conditioners can be found at the Web site of the Air Conditioning and Refrigeration Institute,

Lighting is another significant consumer. Generally, compact fluorescent bulbs are much more efficient than incandescent bulbs. Even though they are more expensive, their long life and high efficiency make them a good buy.

Various wattage bulbs, particularly with incandescent, have different efficiencies. To compare them, read the packaging for the amount of light output in lumens. Take your calculator and divide this by the bulb wattage. This tells you how much light output you get for the amount of electricity being used.

Energy Star ( is another excellent guide when selecting energy-efficient home products. Products that meet their high-efficiency standards are listed in many categories. You will also often see the Energy Star label on the most efficient products in appliance dealer showrooms.

Send questions to James Dulley, Kentucky Living, 6906 Royalgreen Drive, Cincinnati, OH 45244. Go to to instantly download.

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