Kill Your (old) Refrigerator

Energy Star Rebate Check

A few weeks ago I wrote about an appliance rebate program in New Mexico. The NM Energy Conservation and Management Division offered $200 rebates for upgrading either a refrigerator, clothes washer or furnace (lots of $ still available for furnace upgrades). Well, we jumped on it and bought a new Energy Star refrigerator and replaced an early '90's vintage fridge. Thanks to my handy-dandy Kill-A-Watt EZ* I discovered how much money we are actually saving with the new fridge.

* Before I get into an incredibly exciting comparison of refrigerator power usage, let me tell about the Kill-A-Watt EZ. The Kill-A-Watt EZ is a great, geeky and useful device that tracks electrical power usage, calculates energy costs and holds the data in case of a power outage. If you want or need to know how much power a 110-120VAC electrical device ACTUALLY uses (not just the maximum rated power use) on a daily basis - this will tell you. There are a variety of whole-house power meters available (including the one from the utility company) but they only give you an overall picture of power use. A Kill-A-Watt can help you determine precisely which devices in your home are using how much power. If you want to cut your power bill, tracking power use by individual appliance is invaluable knowledge.

The appliance upgrade program was an opportunity to scrap a 1990's vintage refrigerator we have in a rental property. We swapped a 2002 fridge to the rental and put the new Energy Star fridge in our home. In the process, I measured electricity use for each of the three refrigerators. Other than age, each of the three refrigerators was comparable with a top-mounted freezer, 16 to 18 cubic feet and no ice-maker. I tried to keep operating conditions similar for the comparison, although my test favored the oldest fridge as I never opened the door during the test while the newer models were used normally.

Refrigerator Energy Use Comparison

1990 Fridge: 4.62 kW·h / 26.7166 hours = 0.1729 kW·h/hour = 4.15 kW·h/day
= 1514.83 kW·h/year

2002 Fridge: 1.54 kW·h / 40 hours = 0.0385 kW·h/hour = 0.924 kW·h/day
= 337.26 kW·h/year (77.7% less energy use than 1990 fridge)

2010 Energy Star(+) Fridge: 1.36 kW·h / 48 hours = 0.02833 kW·h/hour = 0.68 kW·h/day
= 248.2 kW·h/year (26.4% less energy use than 2002 fridge)

Notes:

  • Energy Star(+). We chose a fridge that was 30% more efficient than the federal standard (the Energy Star requirement is 20% more efficient than the standard).
  • Turn the 'Cool' knob down. At the default thermostat setting the 2010 Energy Star Fridge used slightly more electricity than the 2002 fridge. I noticed that lettuce on the bottom shelf was freezing, so I adjusted the thermostat a few notches warmer and the energy use went down measurably.
  • The results are clear - old refrigerators are huge energy hogs. I was amazed that the 1990 fridge used 4.5 times more electricity than the 2002 fridge! Compared to the 2010 Energy Star(+) refrigerator the 1990 fridge used 6 times more energy! We've cut the (electrical) cord on the 1990 fridge and sent it off to the recycler. I suppose that means it's gone to hog heaven. Good riddance.

    More Info:

    Cold Cash for Refrigerators (Furnaces and Clothes Washers)

    New Mexico Appliance Rebate Program

    Kilowatt hour (kW·h)

    Kill A WattEZ™