Will they really save you energy and money?

If you’re looking at ENERGY STAR refrigerators because you want to save energy with your next refrigerator, you need to do more than just look for the ENERGY STAR label as you shop. The fact is that while an ENERGY STAR refrigerator of a given set of features and cubic foot capacity will use less than a non-ENERGY STAR refrigerator with the same features and capacity, the ENERGY STAR certification is only one variable to consider.

Here’s a simple example: In refrigerators with a 20.5 cubic foot capacity, the most energy efficient refrigerators are rated at 407 kWh per year, which translates into roughly $41 in electricity costs per year, or roughly $615 if you assume a typical 15 year lifespan. The least efficient ENERGY STAR refrigerators of that same 20.5 cubic foot capacity are rated at 527 kWh per year, which is about $53 per year or $765 over a 15 year lifespan. And the most efficient refrigerator in that capacity that is not an ENERGY STAR refrigerator is rated at 409 kWh per year, only 2 kWh per year more than the most efficient ENERGY STAR refrigerator of similar capacity.

In other words, you could decide a 20.5 cubic foot refrigerator is the capacity you need (and I’ll argue further down that that’s probably quite a bit more than most people really to need) and, being a good environmental citizen (or just wanting to save money on your electricity budget), you decide to look only at ENERGY STAR refrigerators, and in the end you could wind up paying substantially more to operate your refrigerator than if you had bought a particular model of non-ENERGY STAR refrigerator.

Let’s look at what contributes to this seeming contradiction. In a nutshell, the discrepancy exists because ENERGY STAR refrigerators are certified based on their energy consumption given a particular set of features. The key features are:

Let’s consider each of these in more detail.

Bottom freezer or top freezer

The US Department of Energy sets different ENERGY STAR standards for refrigerators depending on whether they have a top-mount or bottom-mount freezer compartment. The formula used for fridges with a top-mounted freezer is 8.33 x (Total adjusted volume) + 234.6, while for a bottom-mounted freezer it’s 3.91 x (Total adjusted volume) + 390.15.

What that means is that fridges with top mount freezers are allowed to have a lower base energy usage (234.6 kWh per year) but a higher delta energy usage per cubic foot of space (8.33 kWh/year per cubic foot), while fridges with bottom mount freezers can have a higher base energy usage (390.15 kWh per year) but a lower delta energy usage per cubic foot of space (3.91 kWh/year per cubic foot). For example, if we had two 18 cubic foot refrigerators, one with top-mounted freezer and one bottom-mounted, we can fill in the values to determine what it would take for the two fridges to be ENERGY STAR refrigerators:

Style Volume Volume factor Volume allowance Base amount ENERGY STAR requirement
Bottom 18 3.91 70.38 390.15 460.53
Top 18 8.33 149.94 234.6 384.54

The net effect of this formula is that the smaller the refrigerator, the bigger the gap in energy use between a more efficient top mount refrigerator and a less efficient bottom mount refrigerator. For example, by this formula, very modest 13 cubic foot top mounted ENERGY STAR refrigerators must use less than 343 kWh per year while their bottom mounted equivalents can use up to 441 kWh per year (98 kWh per year more) and still qualify as ENERGY STAR refrigerators. At the massive end of the range, a top-mounted 30-cubic foot ENERGY STAR fridge must use less than 484 kWh per year while its bottom-mounted equivalent is allowed 507 kWh per year, a mere 23 kWh per year more.

I don’t know what is behind the different allowances; it would seem to me that the criteria are set based on the energy consumption of refrigerators that were on the market at the time those criteria were set. It may be that, because bottom mount freezers tend to have larger freezer compartments, an allowance was made for the extra work the compressor needs to do to keep that extra space cold.

Nonetheless you need to consider, for a given set of refrigerators that are ENERGY STAR refrigerators and that meet your needs, what the estimated kWh per year is. For the 18 cubic foot example above, you could buy a non-ENERGY STAR top-mount freezer that uses 386 kWh per year, and save 74 kWh per year, or about $100 in electricity costs over the refrigerator’s lifetime.

Auto defrost or manual defrost

Not many people go for manual defrost these days, because it’s a real pain to deal with defrosting a freezer compartment every few weeks. I remember the refrigerator we had in our first rental house in Toronto – it was from about 1930 and had a tiny freezer compartment inside the refrigerator compartment, that would become coated with so much ice within a couple of weeks of the last time we defrosted it, that there was no room left to store food! And in fact the only ENERGY STAR refrigerators available with manual defrost these days are ones with either no freezer, or with a freezer inside the refrigerator compartment, just as my 1930’s fridge was. If you’re really striving to minimize your home energy use, you might consider what we did when we ditched the 1930’s fridge: we bought a fridge-only unit (17 cubic foot Woods fridge, at that time one of the most efficient units on the market) and a 10 cubic foot freezer (also one of the most efficient). At that time our combined fridge and freezer used less (for 27 cubic feet total space) than most equivalent 17 cubic foot combination fridge freezer units, although refrigeration equipment has become a lot more efficient since the early 1990’s, and these units wouldn’t come close to meeting today’s standards for ENERGY STAR refrigerators or freezers.

If you do a lot of freezing of home-preserved foods or local produce or meat, or you store a lot of store bought freezer goods, this may be a better option than buying a huge fridge with an auto- defrost freezer. The main drawback of this approach is that the freezer is typically off in another, out of the way room; in our case it meant we had to run to the basement every time we wanted an ice cube!

Door ice dispenser

Ice dispensers in your refrigerator door are a great convenience and also a great energy waster. On average, ENERGY STAR refrigerators that have an in-door ice dispenser are about 16% less efficient than equivalent ENERGY STAR refrigerators that lack such a dispenser. If you consider just ENERGY STAR refrigerators in the narrow range of 20-21 cubic feet total capacity, those with ice dispensers average about $922 total operating cost over their estimated lifetime (based on $0.10 per kWh), while those without will cost about $783 to operate, for a lifetime energy savings of around $150. (Of course, this depends on how much electricity costs in your location; for example, in Pennsylvania, a typical cost per kWh at present is closer to $0.20 per kWh, California is at about $0.15 per kWh, and Florida, Texas, and Ohio are all around $0.13 per kWh, so in all those areas the delta cost of an in-door ice dispenser are .) And don’t forget that ENERGY STAR refrigerators with in-door ice dispensers typically cost more, so you pay for the feature in two ways.

Cubic foot capacity

The higher your refrigerator’s cubic foot capacity (or volume), the more energy it can consume while still being an ENERGY STAR refrigerator. Take a look at the following chart, which shows the average kWh per year ratings of about 3800 refrigerator models, grouped by cubic foot capacity and separated into ENERGY STAR refrigerators and non-ENERGY STAR refrigerators. The graph shows both total yearly kWh usage for a refrigerator class, and kWh usage per cubic foot of volume:

Refrigerator kWh consumption/year by size

One interesting thing to note in this graph is that the difference in energy consumption between ENERGY STAR refrigerators and non-ENERGY STAR refrigerators within a given cubic foot capacity is typically less than the difference in energy consumption between one capacity range and the next. So you might be better off, in terms of energy consumption, to buy a non-ENERGY STAR rated at 17.1 cubic feet capacity, than an ENERGY STAR refrigerator with 21.9 cubic feet capacity.

This brings me to one of the most important criteria for buying an energy efficient refrigerator: make sure you buy the right size refrigerator. There has been a trend in recent years to ever larger refrigerators – partly because as refrigerator efficiency inreases, people can afford more capacity for the same energy cost (this is called the Jevons paradox: any increase in efficiency is offset by an equivalent increase in consumption). The trend is also a result of changing shopping patterns: people tend to do more buying in bulk than they used to, for example at Walmart or Sam’s Club or Costco.

My mother in law recently redid her kitchen, and when I saw it during our annual pilgrimage to Ohio last Christmas I could not believe the size of her refrigerator. She lives on her own, so she could probably get by with a 10 to 13 cubic foot refrigerator (GE makes an 11.5 cubic foot refrigerator, model GBC12GAX*,that uses 417 kWh per year). Instead she bought a Fisher & Paykel model RF201ADUX1, with 20.1 cubic feet capacity, that uses 550 kWh per year, or more than 30% more.

And the worst of this is that a big refrigerator tends either to stay empty – in which case, every time you open it, much of the cold air falls out, leading to reduced efficiency – or tends to keep getting fuller, because it’s so big it’s easy to forget the many leftovers stored there, and so they rot. (Americans throw out about 40% of all the food produced in the country.)

ENERGY STAR compact refrigerator

If you’re looking for an ENERGY STAR compact refrigerator, you can get models that consume quite a bit less than a 15 to 20 cubic foot model. But they certainly don’t compare in terms of power consumption per cubic foot of refrigerator volume. Of approximately 300 compact refrigerators on the market, ranging in capacity from 1.6 to 6.6 cubic feet, efficiency ratios range from 37.5 kWh per year per cubic foot, to as high as 185 kWh per year per cubic foot (smaller is better). The main factor affecting the efficiency of an ENERGY STAR compact refrigerator is its volume; the smaller the volume, the less efficient they tend to be.

In the smallest category of ENERGY STAR compact refrigerator – between 1.7 and 2.0 cubic feet capacity, with a freezer typically inside the unit, you would be looking at about 252 kWh per year consumption. Surprisingly, this is more than half the consumption of some ENERGY STAR refrigerators that are ten times bigger. So you should not imagine that buying an ENERGY STAR compact refrigerator is a way to save a ton of money on electricity – it’s just better to buy an efficient compact refrigerator than an inefficient one. (The least efficient compact refrigerator in that range is rated at around 318 kWh per year, which is only about $7 per year more worth of electricity.)

The most efficient ENERGY STAR compact refrigerator models in the 2.0 cubic feet and under range are:

  • Sunbeam model SBCR139WE (1.7 cubic feet, 252 kWh/year)
  • Kenmore model 461.99262 (1.7 cubic feet, 252 kWh/year)
  • Danby Designer model DCRM48SLDD (1.7 cubic feet, 252 kWh/year)
  • Danby model DCR059* (1.7 cubic feet, 252 kWh/year)
  • Frigidaire model LFPH16M4LB (1.8 cubic feet, 252 kWh/year)

But you can actually get more capacity than these, for only 1 extra kWh per year, if you go with any of the following Frigidaire 2.4 cubic foot ENERGY STAR compact refrigerator models, all of which are rated at 253 kWh year: models LFPH25M4LW, LFPH25M4LB, FFPH25M4LB, CFPH25M4LB, or CFPH25M4LW.

The very best, in terms of energy efficiency of an ENERGY STAR compact refrigerator, is actually even bigger – the Fisher & Paykel model RB36S, which is 3.1 cubic feet (but does not have a freezer) uses a mere 145 kWh per year.

Buying the right refrigerator

My recommendation if you’re shopping for ENERGY STAR refrigerators is to start by looking at what you really need. If your current refrigerator seems too small, it’s not necessarily the case that a bigger refrigerator will be better; overfilled refrigerators are often a symptom of an over busy lifestyle, or an unhealthy obsession with sanitation, rather than of the need for more capacity. For example, in Costa Rica, where I lived for a year, most people have either a tiny refrigerator or none at all; even in their hot tropical climate, eggs, cabbages, peppers, and tomatoes, for example, are almost never refrigerated (even in the store). You’ll save a lot over the lifetime of your refrigerator if you can keep it small. Not only will you cut your energy costs but you’ll probably reduce the amount of food you wind up throwing away because it rots before you remember you left it in the caverns of an oversized fridge.

Consider also whether added features like an automatic ice maker or in-door ice dispenser or cold water dispenser are really that important to you. Everyone likes added convenience, but that convenience comes at a cost to your household energy budget, and ultimately to the environment we all share.

Finally, remember to look at the energy consumption label that should be provided with every new refrigerator (this applies to both ENERGY STAR refrigerators and those that are not ENERGY STAR labeled). The energy consumption label should give you an electricity consumption rating in kWh per year, and an indication of how that unit’s consumption compares to others in its peer group (refrigerators with similar capacity and features). You’ll save a lot in terms of the total ownership cost of your refrigerator, if you focus on that kWh per year number, and buy the smallest, simplest refrigerator that meets your needs, than if you go for all the latest coolest features in an oversized unit that happens to have an ENERGY STAR logo.

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