Refrigerators and freezers
Choosing a refrigerator is an important decision for both environmental and financial reasons.
A refrigerator's motor runs frequently and intermittently around the clock, drawing considerable power during the minutes when it runs, so refrigerators are a major user of domestic electricity. The US Department of Energy estimates that a refrigerator uses 14% of a given household's electricity.[verification needed]
Choosing a fridge[edit | edit source]
- Check the star ratings. Higher ratings mean a higher purchase price, but lower operating costs. If you're paying a premium for green power, then it becomes even more cost-effective to buy the more energy-efficient item.
- Do your calculations - while information provided by the manufacturer isn't always accurate, some basic calculations give an idea of how much you can save.
- Choose a size just large enough for your needs - this can also save money. This takes some guesswork, but remember - not so long ago, people didn't have refrigerators, so getting by with a slightly smaller one isn't a disaster. It may force you to clean out the fridge more often, which is often a good thing. Better yet, food items are less likely to become buried, be forgotten, and spoil.
- Be realistic about how much cooking you will do, and how often you will shop for foods that need refrigeration.
- Look for new energy-saving features such as improved insulation.
- Glass shelves are easy to clean and prevent spills going down onto items below.
Types[edit | edit source]
Layout[edit | edit source]
- Freezer inside fridge - when the freezer is a small compartment with its own door within the larger refrigerator compartment, more leakage occurs, meaning lower efficiency. This also exposes the freezer to more moist air, meaning more frost.
- Top freezer refrigerator is found in kitchens around the world more often than other designs. This design is the most affordable. It has the advantage that children can easily access food and drink for themselves.
- Built-in fridge freezers is sometimes chosen for aesthetics, but is more expensive. They typically have to work in more confined spaces with poorer ventilation, making them less energy efficient.
- Bottom freezer refrigerators reduce the need for bending while opening the fridge. (Opening the freezer is usually needed less often.) It may also be more energy efficient.
- Side by side refrigerators use slightly more energy than an equivalent top freezer refrigerator.
- Chest freezers don't allow cold air to spill out when the door is opened, making them more efficient. Refrigerators in this layout are more rare, and finding items can be more of a challenge.
Mechanism[edit | edit source]
- Compressor refrigerators (the most common) make a noticeable noise.
- Absorption refrigerators provide quiet running. These can run on any heat source, including gas or solar.
- Peltier coolers (see Wikipedia:Thermoelectric cooling) can be very compact, but are less efficient.
- Solar refrigerators do not use harmful refrigerants. Typical solar designs are absorption refrigerators that use ammonia as the working gas, and employ large mirrors to concentrate sufficient sunlight to reach the temperature required to free gaseous ammonia from the solvent.
- Thermal mass refrigerators are heavily insulated, so cooling load is limited primarily to heat introduced by new items to be refrigerated, and air transfer while the unit is open. Power consumption is very low if opened infrequently.
- Pot-in-pot refrigerators require no electricity to run, but need to have a source of water
- Magnetic refrigerationW is not used for domestic refrigerators, but has scientific applications.
Features[edit | edit source]
- Automatic ice makers increase the energy use of a freezer, increasing the running cost, as well as adding to the purchase cost.
- Frost free (automatic defrost) freezers use heaters built into the refrigerator's walls to prevent moisture from condensing on the inner surfaces. This can add around 30% to the freezer's energy usage. Some new units have energy saver switches to deactivate these heaters when not needed (e.g. when humidity is low; opening the freezer rarely can help). Keep this switched off whenever practical.
Refrigerators, health and quality of life[edit | edit source]
A refrigerator may be seen as a luxury - however it allows a more varied diet, use of more fresh ingredients, more salads, and thus improved nutrition and more enjoyment from food. Widespread ownership of food cooling devices (whether fridges or an appropriate technology alternative) is thus a reasonable aim for an international development program.
After buying your fridge/freezer[edit | edit source]
For the life of the refrigerator, be aware of the door seals - they must be airtight, or leakage will increase energy usage.
You may see a recommendation to clean your refrigerator coils. This is usually not a good idea and won't save energy - see Should I clean my refrigerator coils.
Where to place your fridge/freezer[edit | edit source]
- Place your refrigerator away from any heat source, such as a stove or oven, dishwasher, heat vents or direct sunlight.
- Keep it either perfectly level, or very slightly tilted in such a way that it always closes. Beware of it being in a position that it easily swings to almost closed, and stay there leaking cold air, unnoticed.
Ensure good ventilation:
- Leave air space between the back of the refrigerator and the wall (at least 7.5 cm, 3 inches)
- Leave air space on the sides back of the refrigerator (at least 2.5 cm, 1 inch)
- Never put a refrigerator or freezer in a cupboard, unless it is designed especially to give very good ventilation.
Temperature[edit | edit source]
- Don't make your refrigerator colder than it needs to be. (INSERT RECOMMENDED TEMPERATURE FOR GOOD FOOD PRESERVATION. 8-11 deg C ?) In the US, those with food handling cards are taught that refrigerators need to be 40 degrees F or below. Check manufacturer guidelines to ensure it is set to the correct temperature. Setting the temperature lower than needed greatly increases energy use, as each degree of temperature reduction uses more energy.
- Use a thermometer to check the temperature, in case the built in one is inaccurate. Place it in a glass of water in the middle of the fridge and leave for 24 hours before reading.
- See if your refrigerator has a "power-saver" and switch to to "ON" if appropriate.
- Room temperature has a very big impact on energy use.
- A garage is usually a bad location due to more extreme temperatures swings. The temperature sensor in the refrigerator may not work at a very low room temperature (below about 5 deg C) leading frozen food to melt in winter.
Recycling and disposing[edit | edit source]
Warning: If you store an old refrigerator or freezer or leave it awaiting collection for a length of time, remove the door so children cannot be trapped inside.
To recycle your unit:
- Many retailers will pick up and recycle your old fridge or freezer when you buy a new one. A list of such retailers in the United States is available at the ENERGY STAR partners page, and the US EPA lists places to get a cash incentive for recycling.
- Contact your local council's waste management department and ask if they collect old units for recycling.
More tips[edit | edit source]
- A second refrigerator left running can cost more than US$120 per year. See if you can consolidate all your food and drinks into one refrigerator.
- One large refrigerator is more efficient (and therefore cheaper to run) than two smaller ones.
- Try to remember where you put things in the refrigerator, and decide which items to remove before you open the door. That will minimize the time that you keep the door open, when cold air spills out and wastes energy. This is much less of an issue with a chest-style refrigerator or freezer with a door that opens upward, as the cold air remains pooled inside with less circulation to the outside air.
- Using transparent food storage containers makes it easier to identify the item you want, so you don't have to hold the door open for minutes while you open containers to inspect them.
- When stocking groceries into the refrigerator, position them all nearby so you can open the door just once and put them all in quickly. It is better to hold the door open just once for a few seconds than to repeatedly open and shut the door between items, which "fans" the interior causing more air exchange with the room.
- The lower you set your building thermostat in winter, the less energy your refrigerator will consume during the cold months. You will also of course save energy on building heat by lowering your thermostat in winter.
- Try to avoid opening your refrigerator door more than necessary during times of peak electricity demand, such as on hot summer weekdays. Opening the door (on a conventional upright refrigerator) lets a burst of warm air rush into the refrigerator as the cold air spills out. This often triggers the refrigerator's motor to run. Using electricity at times of peak demand typically generates more greenhouse gas emissions per kWh consumed, as utilities have to run less efficient peaking generators to meet the demand. The more of your electricity usage you shift to the hours of lower demand, the greener you are.
See also[edit | edit source]
[edit | edit source]
If it's possible to place it in a basements or other cool locations, this can help (though it may or may not be worth the inconvenience).
- Best Practices for Refrigerators - EnergyStar.gov
- refrigeration without power - the cool box
- keeping your stuff cold - discussion at the permaculture forums
- "Chest fridge". Archived from the original on 2011-03-12. Retrieved 2011-03-12. - describes the (allegedly) world's most efficient refrigerator, consumes just 3kWh/month