Before you buy a new fridge, find out how much energy the old one uses
Before you run out and buy a new energy saving refrigerator, it's helpful to understand how much electricity your current refrigerator uses. Why? Here are three reasons.
First, because you'll be looking at Energy Guide labels on the new fridges, to figure out which ones will cost the least to operate, and you might as well know how they compare to your existing refrigerator.
Second, if you are expecting to replace your fridge mainly to save electricity, you might find out that you don't need to. Although modern refrigerators are much more efficient than those of ten years back, your refrigerator may turn out to be efficient enough that there isn't a convincing motivation to upgrade. You might save more energy, for the same price, on adding insulation or upgrading windows.
Third, you may discover your existing refrigerator is using so much energy, that a fridge tune-up will save you electricity even in the few short weeks before you get the new model. Things that have a big impact include: checking the door gaskets for leaks or cracks, checking the temperature (38-40F for refrigerator, 5F for freezer), making sure the compressor and coils are clean; and ensuring good airflow around the unit. Even if you find out that your current refrigerator is an energy guzzler and you do a tune-up, you may discover that the tune-up on its own will result in significant electricity savings.
Your current refrigerator could easily be costing you $25 to $100 a year more than it needs to, and your new unit may prove to be less efficient than its ENERGY STAR label says, depending on how you use it. But if you just blindly assume that a refrigerator uses what its label says, you'll be leaving a lot of savings on the table. Knowledge is key.
What if I told you that a $20 investment could save you at least $40 per year, every year? It turns out that there is an inexpensive tool that can do just what we need: measure the electricity consumption of your fridge.
I got a Kill A Watt meter about four years back and have used it to measure the energy use of many appliances in my home. I have also lent it to many others so they could find energy savings of their own. These devices are available for around $20 and they tell you how many kilowatt hours per day (kwh/day) an appliance like a fridge uses. A measurement takes about three days, because a fridge cycles on and off, and only a longer measurement irons out the peaks and valleys of the fridge's electricity use. But once you have that measurement, you will know what your refrigerator consumes and you can start choosing actions to save electricity, or you will be able to make a more sound decision about replacing your old fridge.
The Kill A Watt meter measures electricity use in a number of ways. The key readings for our discussion are time elapsed and kilowatt hours consumed. The meter measures both of these values as soon as it is plugged in, so if you plug in the meter, then plug your fridge into the meter immediately, you'll start to see how much electricity your refrigerator churns through once at least 24 hours have gone by. Here's the process:
1. Pull your fridge away from the wall. Unplug it and plug an extension cord into the outlet instead.
2. Plug the Kill A Watt meter into the other end of the extension cord, and the fridge into that. Leave the meter where you can see it.
3. Push the fridge back. (You can just stick the meter between the wall socket and the refrigerator, if that enables you to see the unit while you're doing readings.)
4. Wait at least a full day to measure. Ideally you should wait 48 to 96 hours. If you toggle the red button on the meter you will see readings for, among other metrics, the hours and minutes elapsed, and the kilowatt hours consumed. You can compute kilowatt hours per day using this formula:
kwh/day = kwh / ((hours/24)+(minutes/1440))
So if the current reading is 2.37 kwh and the elapsed hours is 34h22m, the kwh/day would be 2.37 / ((34/24)+(22/1440)), or 1.655 kwh/day. Don't wait longer than four days to do your final reading, because the time elapsed measurement wraps back to zero at 99h59m.
Most fridges are rated in terms of kwh consumed per year, so to compare your existing refrigerator with what's available now, you can multiply the kwh/day value by 365. Our example fridge getting 1.655 kwh/day consumes 604 kwh/year. A 16 cubic foot Sun Frost fridge, in contrast - one of the most efficient fridges on the market - uses only 254 kwh/year.
You can see how your old refrigerator stacks up against new models by searching the www.energystar.gov refrigerators database, for models that share features of your fridge. Fridge efficiency standards have increased in the last few years, and a fridge usually uses more energy as it gets older, because of hardening gaskets, dust buildup on compressor and coils, wear and tear on the motor, and occasionally coolant depletion. And ENERGY STAR refrigerators must be at least 20% better than the standard, so if you own an old fridge that was not ENERGY STAR rated to start with, you can see there is a big potential to cut energy use, especially if you know your current consumption.
The efficiency standard for fridges varies based on configuration (top or bottom freezer, side-by-side, or no freezer), volume, auto-defrost features, and coolant type. And the formula is so complicated that few people other than US EPA and DOE officials, and appliance company engineers, can really grasp it. So rather than quote the standard let's consider a couple of examples.
An ENERGY STAR rated, 10 cubic foot, auto defrost unit that uses 309 kwh/year, is 21% better than the minimum standard for its class.
A 14 cubic foot partially automatic defrost refrigerator that uses 254 kwh/year, is an amazing 36% better than the standard requires.
As you can see, even for units that have an ENERGY STAR label, there is a big range of efficiencies, and remember that a large unit that exceeds the standard by 36% may still consume more energy than a smaller refrigerator that exceeds the standard by only 20%, if the minimum standard for the two refrigerators is different. If you can choose a smaller refrigerator when you buy a new one, you will definitely save more money.
Once you know how much energy your fridge consumes (it will probably be somewhere between 400 and 600 kilowatt hours per year, depending on the size of unit, or even more if you have wasteful features such as side-by-side fridge and freezer compartments or an ice and cold water dispenser) you can compare the consumption of your refrigerator to those at the ENERGY STAR website, and decide if it's time to do a fridge tune up, or replace your fridge altogether.
If you're in luck, you might discover that the model you have now is already an energy efficient fridge. If not, at least you'll have a great tool for checking whether your new refrigerator measures up to its billing.
Robin Green owns www.Green-Energy-Efficient-Homes.com, a website that helps people cut their home energy use. For more on saving electricity with your fridge, see Energy saving refrigerators and Kill A Watt meter on Green Energy Efficient Homes.
www.energystar.gov
