Danby DPR2262W Propane Top-Freezer Refrigerator

* 7.8 cu.ft Capacity

* Top-Freezer (most efficient arrangement)

* Manual Defrost (more efficient than automatic)

* Reversible Door (adjusts to tight spaces)

* $1079

A refrigerator is usually the single largest electrical load within a house; a refrigerator uses more energy than the stove and oven, microwave, dishwasher, dryer, and often the total installment of incandescent lights. This is because a refrigerator runs all day and all night.

But, the damage can be minimized with refrigerator maintenance. Anyone who spends a few minutes a year can increase their refrigerator’s efficiency by at least 30%. That would save about $40 a year for a typical 1990 refrigerator, according to the Department of Energy’s calculations. In fact, the DOE claims that cleaning coils alone can save up to 30%, while other measures, such as replacing the gasket and using the “energy saver” switch, can yield additional savings.

This will save a good amount of money and energy. But it is often also wise to upgrade to a new, energy efficient refrigerator. You can enter the model number into the Energy Star savings calculator to see your potential savings. If you upgrade now, over five years, you can expect to save:

• $230 for replacing models older than 2,000
• $450 for replacing models older than 1992
• $665 for replacing models older than 1989
• $910 for replacing models older than 1980

This is for upgrading to a typical Energy Star refrigerator. See the Buying Guide for guidelines on how to maximize these savings. Or, if you desire to move towards a sustainable household, you may want to see the list of the Most Energy Efficient Refrigerators. These are especially well suited for powering with renewable energy.

Can’t afford to buy a new refrigerator? Maybe you can’t afford not to: see Low Cost Refrigerators and Refurbished Refrigerators.

Feel free to send me questions and comments at brad@refrigeratorefficiency.com

Taking the initiative to live off-grid calls for an especially close look at the types of refrigeration and their respective costs and benefits. The initial cost of a power source (such as solar panels or windmills) is large, and usually every penny invested in a highly efficient refrigerator will come back manifold through reduced equipment capital.

Standard AC Refrigerators

There are a few different options for refrigerating food items off-grid. A common method is to use a standard AC refrigerator (such as most people have in their homes) in conjunction with an inverter, which converts electrical current from a solar or wind charged battery to a typical 120 V AC current. Houses that generate electricity on site usually have an inverter anyway, so a high efficiency AC refrigerator is a very good option for such conditions.

DC Refrigerators

Some refrigerators come in either an AC or DC design (powered by either alternating current or direct current). DC designs are hooked up directly to a 12 V or 24 V battery, using wire leads to hook the battery terminals to the compressor terminals. DC refrigerators are useful for mobile homes or RVs. Or, if you own a stationary house but it is not equipped with an inverter system, a DC refrigerator is a great way to utilize power from solar panels or wind turbines.

Propane Refrigerators

A third option is the usage of a propane refrigerator, which obtains energy solely from propane tanks. A propane fridge is less cost and energy efficient than electric refrigerator, but has certain benefits. If your home is powered entirely by an on-site energy source, a propane refrigerator can lessen the demand on that source which can free up enough electricity for other vital appliances at peak hours, not to mention ensure uninterrupted refrigeration. The fact that propane refrigerators require no external power source make them ideal for RVs and mobile homes.

1. Maytag MTB2254EE

* 21.7 cubic feet

* 424 kwh/year (about $44.50/year*)

* Energy Star Qualified (20% above Federal Standard)

* One Year Warranty

* $929

2. Whirlpool W2RXEMMWQ

* 21.7 cubic feet

* 422 kwh/year (about $44.30/year*)

* Energy Star Qualified (20% above Federal Standard)

* One Year Warranty

* $839

* Annual operating costs are based on a national average rate of 10.5 cents/kwh, and the U.S. government’s Energy Star tests.

Other Options

For state of the art performance, see the list of most energy efficient refrigerators.

What To Look For

An Energy Star refrigerator may have an efficiency anywhere from 10% to over 50% better than the average model for that particular design. However, whether it saves 10% or 50% they both receive the same Energy Star label.

What consumers should really pay attention to is the Energy Guide Label, a bright yellow label required on all appliances that shows the average annual electrical consumption based on government tests. The label will also show where it ranks on the spectrum of efficiency for similar refrigerator models.

However, the spectrum on the Energy Guide label can also be misleading because it only references the same narrow category of refrigerators as Energy Star. The one metric that really matters is the annual energy rating.

To find an appliance with a low energy rating, it is necessary to have a basic understanding of how different designs can affect the overall efficiency. Since Energy Star and the Energy Guide Label always compare efficiencies between similar types of models, they do not help consumers choose the most energy efficient types of refrigerators and freezers.

Side-by-Side versus Top-Bottom

There are basically three categories of combined refrigerators and freezers: side-freezer, top-freezer, and bottom-freezer. Tests show that top-freezer models are 10 to 25 percent more efficient that side-by-side models. Bottom-freezer models are in between the two.

Chest Freezers

Chest freezers are usually more efficient than upright freezers. Besides being better insulated, the chest freezer is positioned correctly to hold cold air. When you open a freezer, you have probably seen the cold air spill out because it is heavier than the room’s air. Since a chest freezer opens from above, it prevents the cold air from “spilling”.

Manual Defrost

Automatic defrost freezers can consume 40 to 50 percent more electricity than manual defrost freezers. Automatic defrosters alternate between heating cycles and cooling cycles. Because the compartment must be kept at freezing temperature during these alternations, the compressor must work extra hard. In other words, the heating and cooling cycles inevitably fight against each other. The buyer must ultimately choose between convenience and saving energy and operational costs.

Automatic Ice Makers

Automatic ice makers introduce another necessary choice between convenience and efficiency. Through-the-door ice dispensers decrease refrigerator efficiency by 15 to 20 percent and increase the up-front cost of the unit by $75 to $250.

Suggestions

This Samsung Energy Star Refrigerator with Bottom Freezer rates 21% above Federal Standards for efficiency. With a stainless steel exterior, 18.72 cubic feet of storage, and sticker price of $900, it is running a 5 star rating on Amazon.

Refrigerator-Freezer Combinations

Avoid: Sun Frost RF-19

Sun Frost rates this model at a consumption of .77 kwh per day, or 281 kwh per year. Unfortunately, it is not verified by Energy Star and I cannot necessarily recommend it.

I compared Sun Frost’s quoted daily energy usage at 70 degrees Fahrenheit with Energy Star’s actual test data for the RF-12, RF-16, and R-19. As can be expected for any manufacturer, the quoted efficiencies of their products performed lower than actual third party testing. The RF-12 performed 38% less efficiently than quoted, the RF-16 31% less, and the R-19 41% less. Using the average of these results, it can be estimated that the RF-19 will use 443 kwh per year, based on their quoted consumption.

This is hardly impressive for its size and cost. While other Sun Frost models have demonstrated fantastic technology with third party verification, this model for some reason seems to be sorely lacking.

Energy: 281 kwh per year (unverified)

Sun Frost RF-12

The Sun Frost RF-12 is the most energy efficient, Energy Star, refrigerator-freezer on the market. A comfortable size for 1 to 2 people, this unit amazingly uses far less energy than the smallest micro-fridges available anywhere.

Energy: 171 kwh per year

Storage Capacity: 10.12 cu.ft.

Efficiency: 16.9 kwh/cu.ft.

Cost: $2,395 (AC model)

Sun Frost RF-16

A good size for 2-4 people, the Sun Frost RF-16 is just slightly less efficient than the smaller RF-12. Containing over 14 feet of storage, it also uses less energy than just about any micro-fridge, making it a good long term investment in lowering utility bills and environmental stewardship.

Energy: 254 kwh per year

Storage Capacity: 14.31 cu.ft.

Efficiency: 17.75 kwh/cu.ft.

Cost: $2,949 (AC Model) ($68 below retail price)

Samsung RF266AB**

The Samsung RF266AB is a spacious, elegant, affordable, and feature rich option. It features 5 spill proof glass shelves, french doors, and a twin cooling system with power freeze/cool options.

Energy: 470 kwh per year

Storage Capacity: 25.84 cu.ft.

Efficiency: 18.19 kwh/cu.ft.

Cost: $1,599.00

Refrigerators (Without Freezers)

Sun Frost R19

The Sun Frost R19 utterly dominates the competition in energy efficient refrigeration. In terms of energy-to-size ratio, the Sun Frost refrigerator is 25% more efficient than any stand alone Energy Star refrigerator, and 53% more efficient than the Federal Standard. This refrigerator is also more spacious than the Sun Frost refrigerator-freezer combos.

Energy: 204 kwh per year

Storage Capacity: 16.14 cu.ft.

Efficiency: 12.64 kwh/cu.ft.

Cost: $2795 (AC Model) ($115 below retail price)

Sub-Zero B136RS*

The Sub-Zero B136RS* ranks second best in energy-to-size ratio out of all Energy Star refrigerators.  It rates 21% above the Federal Standard and has storage volume comfortable for the needs of 4 to 6 people.

Is it worth it?

For houses that run off on-site renewable energy (such as solar or wind), a rule of thumb is that $1 invested in energy efficiency saves $3 in the cost of power generation. Therefore, if you spend $1,000 for an extra efficient refrigerator you may be able to save $3,000 on the solar panels or windmill needed to run it.

Furthermore, if you live in a warm climate or somewhere with higher cooling costs than heating costs (which is most of the U.S.), a more efficient refrigerator will actually cut down on your net cost of heating and cooling. This is because ultimately, 100% of a refrigerator’s energy is converted into heat, due to the entropy of the refrigeration cycle. Being one of the largest household loads, a more efficient refrigerator significantly reduces the workload of the cooling system, especially for warmer climates.

Looking for Something Cheaper?

If you just need something cheap and energy efficient to plug into your electrical outlet, see the most energy efficient refrigerators under $1,000.

Size and Efficiency

The first indispensible rule of thumb is: do not buy a refrigerator sized too small for your needs. When seeking out an energy efficient refrigerator it may be tempting to pick one with the lowest energy rating. But, if it does not meet your storage needs and you end up using an auxilliary refrigerator, that is a backwards step in both cost and efficency. Even if you expect to fill two 15 cu.ft. refrigerators with food, that would be less efficient than a single 30 cu.ft. refrigerator because two units contain a much greater surface area.

The second rule of thumb is: don’t just buy the largest refrigerator you can find. While larger refrigerators tend to have a better energy to size ratio, habitually cooling empty space is an unnecessary addition to the electrical bill and to the initial purchase price. Still, it is better to err on the larger side. A refrigerator sized 10 cu.ft. too large for your needs almost invariably wastes less energy than buying even the smallest auxilliary fridge or freezer.

Choosing Among Refrigerator Sizes

The best way to choose among refrigerator sizes is to make an assessment of your current refrigerator. Could you use maybe 25% more space? Or 25% less? If you do not know the storage capacity of your fridge, look up the model number on the sticker. Then enter it into the Energy Star website, which will give you the exact volume of your model.

The dimensions of your kitchen are of course important in choosing compliant refrigerator dimensions. When comparing room measurements to refrigerator dimensions, always tag on a couple inches to the sides and rear of the fridge dimensions. This will leave enough space for air to circulate around it, letting it run at optimal efficiency.

We would still have exactly as much energy at our disposal.

The change would cost nothing; in fact, it would save each person about $50 a year.

How

Refrigerators are energy intensive. Old refrigerators can use over 2,000 kwh per year. Even modern, “efficient” refrigerators can use up to 600 kilowatt hours per year. That is the amount of energy it takes to light up ten thousand incandescent light bulbs for an hour.

According to the U.S. Department of Energy, cleaning your refrigerator coils just once every 6 to 12 months will increase the efficiency by up to 30%. It’s as easy as 10 minutes of dusting.

That is significant. My parents’ fridge, a 1986 Whirpool, clocks in at 1,508 kwh per year. At 10.5 cents/kwh, cleaning the coils offers a savings of $47.40.

For 10 minutes of work, that is $284.40 an hour! Most productive 10 minutes you’ll spend all day.

Decrease Fossil Fuel Consumption

On March 28th of this year, hundreds of millions of people turned off their lights to celebrate Earth Hour. Cities around the world saw a dip in power consumption by anywhere from 2 to 15 percent during that hour.

But how effective could this be if Earth Hour was replaced by “Fridge Minutes”? Let’s estimate that the average household has 10 incandescent light bulbs running at night. Earth Hour then saves:

10 bulbs x 60 watts/bulb x 1 hour = 0.60 kilowatt-hours each year.

Conservatively estimating the average fridge uses 1,000 kwh per year, cleaning the condenser coils saves:

30% * 1,000 kwh =  300 kilowatt-hours each year.

Conclusion?

If you spend 10 minutes once a year to clean your refrigerator coils, that saves more energy than if you would sit in the dark for one hour, every day of the year.

Power of Combined Effort

A nuclear power plant produces about 1,000 MW of power, producing nearly 9 billion kilowatt-hours over a year. If we assume that the U.S. contains 1 refrigerator for every 4 people, and the average fridge uses 1,000 kwh per year, a little fridge maintenance could replace two or three of such nuclear power plants.

Try it yourself; look up your fridge model number with the Energy Star Calculator, and see how much you could save.

Use the “Share” button below to tell your friends!

Standard Refrigeration Cycle

The most basic explanation is that it transfers heat from inside the refrigerator cabinet to outside; it does not “create” cold air. The way it performs this transfer is through the flow of a refrigerant. You may think of a refrigerant as a cold fluid, but that is not entirely true. It is cold when it runs through the coils inside the fridge but quite warm when running through coils outside the fridge. To understand exactly how it does this, you need to get familiar with the basic refrigerator parts.

Heat Exchanging Coils

You can see these on the back of smaller refrigerators and also maybe inside, perhaps next to the ice tray. The important thing to know is that if you could follow a single strand of the coil through all of its twists and turns, it would make a full circle through the inside to the outside of the fridge. All of that convoluted piping is really just one big loop, as shown in the diagram above.

Which raises the question, if it is just one big loop why does it look so complicated? Most simply, all of that zig zagging is intended to increase the piping’s exposure to air. When the refrigerant runs through the outside portion of the refrigerator (stage 1), heat is conducted to the air. The refrigerant is simply warmer than the air, and it loses its heat in exactly the same way you lose body heat when out in the cold. If it just made a short peak out of the back of the fridge and headed back in, there wouldn’t be much time for heat transfer to occur.

Compressor

So how does it get warmer than room temperature? Isn’t it strange that it could be warm right after leaving the inside of the fridge? Consider a second question. Why do some mountains have snow at their peaks but not at their bases? If you can answer either one of these questions, you can answer the other.

Mt. Fiji contains the same gaseous states as a refrigeration cycle.

The answer is the Ideal Gas Law. The Ideal Gas Law finds that a gas will decrease in temperature when it decreases in pressure. At the top of Mt. Fiji, the air is very thin and low pressure because there is much less air sitting on top and compressing it than at sea level.

Likewise, after hanging out inside the fridge for a bit the refrigerant has only warmed to near fridge temperature; maybe 35 to 37 degrees (stage 3). But then it enters the compressor (stage 4). The compressor does exactly as it sounds; it puts a great deal of pressure on the refrigerant. This is like pushing that thin, cold air at the top of Mt. Fiji down to ground level. Or, think of it as the squeezing of a sponge. It “squeezes” the refrigerant, making it temporarily warm so that it loses heat to the surroundings. Now, when it is “unsqueezed” it will be able to “soak up” more heat.

Expansion Valve

The next logical question is: what “unsqueezes” it? This is the work of the expansion valve (stage 2). In more exact terms, the expansion valve converts the high pressure, low velocity refrigerant into a low pressure, high velocity mode. This lowers the temperature as the ideal gas law describes.

If that seems complicated, try this. Put your hand in front of your mouth, make a small circle with your lips, and blow. Notice that the airstream feels cool. The air in your lungs is like the high pressure region of the refrigerant, and the airstream hitting your hand is like the low pressure region. Your lips are like the throttle valve. The throttle valve itself is nothing but a small opening.

Since the refrigerant has cooled to almost room temperature just before passing through the throttle valve, when it passes through it loses a great deal of pressure and becomes very cold. It then can cool the interior of the refrigerator again(back to stage 3).

Millions of refrigerators are put into retirement every year. They make have broken down, or the owners may have just wanted a different size, look, or style. An executive from Brody, Weiser, and Burns found that 16% of discarded refrigerators are still in working condition.

Ebay Search: Refurbished Refrigerator

Most refrigerators can be refurbished or reconditioned to be in like-new condition. This may involve replacing drawers and shelves, mechanical parts, and putting on new coatings. This requires some work, but it is invariable more ecologically sustainable than manufacturing refrigerators from scratch. Buying a refurbished refrigerator is a good “green” choice for a few reasons.

Benefits

Refurbished refrigerators have lower “embodied” energy. These days we always pay attention to the efficiencies of our technologies, but often forget the energy consumed in manufacturing the product or appliance itself. Refrigerators use most of their energy in the act of cooling, but the energy used in producing them is not negligible, nor is the usage of natural resources.

The efficiency of refrigerators has been steadily increasing over the past couple decades. However, this doesn’t mean we have always moved in a forward direction in all aspects of design. The refrigerators of the 50s and earlier were often heavily insulated, even taking on a “puffed” appearance.

Jennifer Van Der Meer, a leader in the green design industry, notes that throughout the 60s and 70s insulation was sacrificed for a more spacious refrigerator box. However, this caused the outside of the refrigerator to become cold and start to “sweat”. Designers remediated this by installing heaters within the refrigerator walls, further worsening their efficiency.

While refrigerators from the 70s have similar shapes as modern ones, refurbished refrigerators from the 30s, 40s, and 50s are becoming popular for their unique style and appearance. Several companies refurbish vintage and antique refrigerators to a clean, functional, and durable state. Some companies even imitate the appearance of the antique design in newly manufactured models.

Modern Technology, Classic Design

Refurbished refrigerators sometimes contain the best of both worlds. The refrigerator cabinet may be thick and insulated, while the compressors are replaced with newer, energy efficient compressors and the system recharged with more environmentally friendly refrigerants. One company, Big Chill, designs new refrigerators with “retro” cabinets, made using traditional processes. These are combined with mechanical equipment efficient enough to earn them Energy Star ratings, each at 443 kWh per year.

While it’s possible to pay a hefty sum for a restored vintage refrigerator, many good deals can be found through trading sites like Craigslist and Ebay. For those who could care less for the antique status or state of the art efficiency, a reliable unit can sometimes be found for less than half the original price. By keeping the refurbished refrigerator in top condition, one may even rival the efficiency of a new Energy Star refrigerator that nevertheless recieves negligible maintenance.