Ask Focus on Energy

This depends on the age of your freezer

Purchasing food in bulk and storing it in a freezer is a great way to save money. But if you store food in an older freezer, your savings may be just an illusion. A freezer purchased before 1993 costs you an extra $35 each year to run compared to a new ENERGY STAR qualified model. Replace your old freezer with a new ENERGY STAR qualified model and use your utility bill savings to stock up on food for your family.

If you purchasing a new freezer make sure it is appropriately sized. Generally, the larger the freezer, the greater the energy consumption. Also, consider whether an upright or chest freezer better meets your needs. An upright freezer has a front-mounted door like a refrigerator and shelves that allow for easy organization. While a chest freezer typically requires more floor space, it’s usually more energy efficient, since the door opens from the top and allows less cold air to escape. Follow these guidelines from ENERGY STAR to reduce the amount of energy your freezer uses.

To find out more about your household appliances and how much energy they use, view our appliance energy use fact sheet. Or, you can use a watt meter. A watt meter is a fun way to find out how much electricity home appliances and electronics consume. (A watt meter is an electronic instrument that measures the power (watts) used by devices. When you plug the meter into the appliance, you can measure how much electricity your appliances/electronics are using and what they are costing you.)

You can measure the electric usage of your freezer using a watt meter and the following directions:

1. Unplug your refrigerator. (It will only be unplugged for a few moments; there's no need to empty the refrigerator or freezer.) Plug the watt meter into the same socket.
2. Plug the refrigerator cord into the watt meter. The watt meter will automatically begin measuring the electricity used by your refrigerator.
3. The watt meter will first show you the estimated cost of the electricity being used. Push the MODE button once so it displays kilowatts (KW). This is the number of kilowatts being consumed by your refrigerator. You are likely to see: 0 to 40 watts if the refrigerator is not running, 150 to 400 watts if the refrigerator is running.
4. The MODE button will switch readings from the kilowatts (KW) being consumed, to the length of time (HR) the unit has been running, to the total kilowatt hours (KW/HR or kWh) of electricity consumed. You will need all three measurements for an accurate calculation, so be sure you're comfortable finding the readings.
5. When you open the refrigerator door, the watt meter reading should go up by 10 to 40 watts. This is the amount of electricity used by the light bulb inside the unit. If the meter reading remains the same when you open the door, the refrigerator light bulb may be on even when the door is closed, warming the interior unnecessarily. If the meter doesn't change, unscrew the light bulb and check the reading again.
6. After you've become familiar with the readings, unplug the meter cord and plug it back in so the time is reset to 0.00.
7. Let the meter run for at least two uninterrupted hours. Keep the refrigerator door shut during this time.
8. After two hours, use the MODE button to find the HR and KW/HR readings. If you ran the meter for two hours, the KW/HR reading should be between 0.100 kWh and 0.700 kWh.
9. Multiply the KW/HR total by 12 to get a daily usage. Then you can multiply by 365 to get annual electric usage of the refrigerator.

Interpreting the results: For comparison sake, a new ENERGY STAR qualified freezer costs approximately $75 per year to operate.

Visit your local library to see if they have a watt meter you can borrow. If your library does not have a watt meter at that location, they can get one through an inter-library loan.

Published Monday, September 14, 2009