One appliance that forms the base line of our monthly energy usage is the refrigerator. This is the one device you can not go without. You can’t shut it off just because energy prices are high, your food would spoil. And what about that frosty reward after a long day??? Or a frozen one when it’s really hot out?? The refrigerator is on 24/7/365 so if it is using a lot of energy then it is using it all the time. If you are on time of use then the refrigerator will compound your energy charges during peak demand times.
Refrigerators are expensive to replace. A quick search of any big box store shows available refrigerators from a low of $900, to a high of $10,018. Replacement may not be a current option so lets start with what you have and go from there.
The first step of every energy conservation project is to measure what we are seeking to improve. Ideally you would collect 12 months of data so you get the seasonal fluctuations included in your analysis but I’m going to assume you want to take action sooner than next year. The first device you should add to your energy auditing kit is a Kill-a-Watt. The Kill A Watt is an energy usage monitor you plug inline with any standard 120 volt appliance. The device has a display with buttons which toggle the display through different pieces of information.
There are different models at different price points. You don’t have to buy the most expensive model and I will base this article on the lowest priced unit. Just make sure you read the directions and do some test audits first to learn how your energy monitor works. The unit I’m using does not have a memory so once you unplug it or de-energize the circuit you will lose all your data. Make sure you get your data before you unplug. Something that makes reading the meter a lot easier, especially behind a refrigerator, is to get a short extension cord. Don’t get the cheap dollar store 24 gauge wire cord, get something with 14 gauge wire or better. The refrigerator uses a lot of energy and you don’t want to create an unsafe condition using an undersized extension cord. With an extension cord you don’t have to move the refrigerator to get to the meter, you can have it off to the side for easy access.
So order yourself a meter and short extension cord. You might want to get a couple as the information you start to learn makes you want to meter everything. Once your new toy arrives get someone to help you move the fridge out. You need to get access to the refrigerators power cord which is usually behind the refrigerator. If you can get to the outlet without moving the refrigerator then you get to skip a step! Shut the power off at the electrical panel before you start. The refrigerator should be on its own labeled breaker if your in a newer house, have your friend stand there while you flip breakers until it goes off if your in an older house. Your going to be temped to sweep out the fruit loops and cat hair under there, don’t do it yet, we need to measure the system they way you have been using it. Be careful of the water line if you have an ice maker. Remember this is a large heavy appliance so you need to be careful. Unplug the fridge from the wall, the start with plugging your extension cord into the wall, then plug your Kill-A-Watt into the extension cord, then plug your refrigerator into the Kill-A-Watt. Stage the extension cord, Kill-A-Watt and refrigerator power cord so you can move the unit back into place and still see the meter being careful not to pinch any of the wires under the refrigerator. Turn the power back on to the refrigerator.
You should now have a reading on your Kill-A-Watt, most likely the voltage. Scroll through and learn what the different values are when you press the buttons. The value you are going to monitor is the kilo-Watt-hour (kWh) reading, usually a purple button all the way to the right. This measures energy usage over time. This is going to be a low value since it just started recording. Now you need to come up with some time frame of when you are going to come back and collect the data. Ideally you should collect at least a week of data, the longer you can collect the better. If you come back after a week you are going to have a number on that meter and that is going to be the kWh energy usage of your refrigerator per week. To get an estimate of yearly energy usage we multiply this times 52.
Let just say your refrigerator used 24.0 kWh for the week. To get the full year estimate we multiply 24 kWh times weeks to get 1250 kWh per year. Next we need our per kWh energy cost. If you don’t know this read our explanation here. My average kWh energy costs is $0.42 per kWh in July 2022. This means our refrigerator is costing about $525 per year to run. What if the energy guide label says our refrigerator should only be using 725 kWh per year? The label is just that, a guide and there are other outside conditions such as the refrigerator location which will impact the total energy usage.
The first step is the easiest but the least popular, clean the area under and around the compressors and coils. Everything in the kitchen seems to be attracted to the refrigerator so there is a time capsule of cereal and bottle caps to get nostalgic over. Pet hair weaves into a quilt which blocks the air flow to the coils causing the compressor to work overtime. Its the type of hair that sticks to you and the refrigerator but not the feather duster so have fun. Once you have everything all cleaned up put a reminder in your calendar to check back in 3 months so you don’t end up with the same mess you just cleaned up next year.
Many refrigerators have the compressor and coils on the bottom and were designed to have air flow in front of and behind these parts. Many kitchens have the refrigerator flat up against a wall with cabinets on two sides which blocks the flow of air over the coils. The other common practice in many kitchens is to put the mop and broom or step stool in the space between the refrigerator and the cabinets. Don’t do this as you want to get as much uninterrupted air flow across the coils as possible. Ideally read the owners manual and follow the manufactures instructions for clearances for air flow. If you can’t find your owners manual then at least move the mop and broom someplace else and pull the refrigerator a few inches off the wall so the air can flow through the unit. If you are designing a new home then keep these principals in mind when you design your kitchen.
Check your temperature settings also. If food is getting frozen in the fridge then its a sign the temperature is set too low. The lower the temperature settings the more energy your unit will use. Try raising the temperature a few degrees and check back in a week. It will take a few days to a week for the temperature to equalize after you have made a change. The temperature sensors in your refrigerator are not the most accurate so getting a second opinion from a unit like this may save you some frustration if you have made adjustments but are still getting frozen food.
One last tip is to keep your refrigerator partially full. Solid matter does not change temperature as quickly as the air so there is less of an energy penalty for opening and closing the door. When you open the door of an empty fridge the cold volume of air in the unit is quickly replaced with room temperature air. When you open the door of a full fridge there is not as much air to replace and the cold food reduces the swing in temperature you would have had with an empty unit.
Lets say you found some extra change in the couch cushions and can’t decide to stuff it in your piggy bank or to buy a more efficient refrigerator. Lets take a closer look at the fridge, just don’t stand there with the door open. I found a 20 cubic foot top freezer energy star rated model from a major manufacturer in stock that uses 387 kWh per year according to the energy guide label for $799 plus tax. Lets round up to $880 for taxes and assume delivery is free. Lets compare the new option against our current unit.
- Old unit
- 1250kWh X $0.42 = $525 per year
- New unit
- 387 kWh X $0.42 = $163 per year
- Savings per year
- $525 – $163 = $362 per year
- Simple pay back
- $880 / $362 = 2.43 year payback from savings
If the new model is the same capacity as the old unit then it makes good financial sense to invest in the new model.
I will update this article with more information and results from refrigerators I audit so you have some comparisons. Feel free to send us your results or questions to Energyhelp@aae-hers.org.
