Editorial

Sunfrost - Untruth in Advertising?

We first published this editorial in early 2001, and have revised it several times. The last revision was August 2007.

It is worth noting that even after 7 years, SunFrost has yet to challenge anything that we say here.

We no longer carry SunFrost - in fact we quit carrying them about 7 years ago, after selling them for over 15 years. For several reasons. Read below to see why a SunFrost may not be the solution that they claim:

"Refrigeration is typically the largest consumer of electrical energy in an energy efficient home. However, the energy efficient SUN FROST refrigerator makes powering a home with photovoltaics, wind, or other low output energy sources both feasible and affordable. In a home using utility power, energy consumption for refrigeration is typically cut by a factor of 5 (80%). Along with energy efficiency, the Sun Frost offers other amenities not found in conventional refrigerators, such as food-saving, high humidity storage, quiet operation, and an easy-to-clean interior.

The Sun Frost refrigerator typically reduces refrigerator energy consumption by a factor of five. The accompanying cost of the solar power system is similarly reduced. The SUN FROST RF-16 12 volt DC model consumes 20 KWH per month, or an average of 53 amp hours per day. By contrast, conventional refrigerators typically consume about 110 KWH per month or 305 amp hours per day. Producing the 110 KWH needed to run this refrigerator on a solar power system would require an investment of around $12,000 in hardware, batteries, and inverter. A Sun Frost will reduce this cost by a factor of at least six because of its increased efficiency and the elimination of inverter losses. Inverters convert DC battery power to 120V AC."

And it goes beyond what they put in print - at an RE show a few years ago, I heard a Sunfrost rep claim that the RF16 used only 8% as much power as a standard refrigerator. That is obviously total crap, but it was being sold as gospel. (in fact it is from 55% to 110% as much).

Even now (April 2007), they still make claims like "Producing the 110 KWH ( per month) needed to run the typical refrigerator..." and "A Sun Frost RF16 will reduce this cost by a factor of at least six..". Both statements are plainly and obviously false, yet the same mantra keeps getting repeated. And if you do an internet search for "SunFrost", you will see the same statement time after time repeated on hundreds of websites (none of who have actually bothered to check the facts, apparently). A check in August of 2007 of the energy star website for refrigerators shows that many in the 18-21 CF range come in at under 400 KWH per year - which is a far cry from the 13,200 claimed by Sunfrost. And a typical one, like one Kenmore model rated 367 KWH per year costs over $2000 less than the Sunfrost RF19.

The above statements are directly from the SunFrost literature and/or website.

We have done our own checking, and it appears that some of the claims are highly exaggerated, and a few are downright false or misleading.

In a statement from SunFrost, they say that the 80% figure is for ALL EXISTING refrigerators currently in use in the US, and NOT compared to new refrigerators (we have serious doubts about that statement also). This ignores the fact that most of the new Energy Star rated standard refrigerators come close to the efficiency claimed by SunFrost, and some are higher - and cost MUCH less. For example, the Kenmore (below) uses 407 kwh per year, while the Sunfrost specifications for their RF19 CF model shows that it uses 390 kwh - a difference of less than 10%. Information is from www.energystar.gov. Also, the Whirlpool 14.5 cu-ft ET5WSEXKQ is DOE rated at 372 KWh per year, or 1.02 KWh per day and sells for around $450 - a far cry from the $2400-3300 for a SunFrost. Whirlpool also has a rebate finder for purchasers of Energy Star rated appliances.

And even their size-model numbers are misleading - they call the R19 a 19 cubic foot, but it is actually barely over 16 cubic foot capacity.

This information is directly from the Energy Star website. At 416 kwh per year, it actually comes out about the same as the SunFrost (using the SunFrost listed specifications).  The nearest equivalent size SunFrost is rated at 1.03 kwh per day, or 376 kwh per year. Also, the Kenmore data includes auto-defrost, while the SunFrost is manual defrost. The SunFrost costs almost $2000 more than the Kenmore.

ENERGY STAR Qualifying: Yes Brand: Kenmore Model: 7387*10*

Volume (ft3) 18.79 Config: TF-A Ice?: No KWH/Year: 407 NAECA Std: 490 % Less Energy: 15%

We noticed that Danby placed fairly high in the 2006 ratings. Sunfrost is still in the ratings, but has lost some ground. Oddly enough to some, Samsung placed highest in the small sized refrigerators (under 7CF) Samsung SKR1373 was the top rated unit for 2006 as of April.

For detailed information and complete listing of all models, see the Energy Star website.

But here is the catch:

In looking at the tables above, you can see that the Sunfrost R19 (refrigerator only model) uses 204 kwh per year, and the Kenmore uses 407. Seems like quite a savings - and it is, energy wise.

Money wise - or system total cost wise, it is not such a good deal. Assuming you get a yearly average of 5 hours full sun per day, the Sunfrost will need about two 120 watt solar panels to run. The Kenmore will need 4. The Sunfrost, with freight and delivery charges, and the stand, will run about $3300. The Kenmore will run you around $700. That would leave you $2600 to spend on more panels - or about 500 to 600 watts of solar panel. So basically, if you buy the Kenmore, you have enough left over to buy the two extra panels + good sine wave inverter. Of course there is another problem - the R19 has no freezer. if you want the RF19 with a freezer, then the energy usage is almost exactly the same as the Kenmore - which also has a freezer and more capacity. Perhaps that is why the RF19 did not qualify on the governments Energy Star program.

In testing 3 standard refrigerators with the Brand Power Meter, and in comparing government standard tests, it appears that rather than the factor of five, it is actually much closer to 1.1 to 1.5 times when compared to equal sized refrigerators with Energy Star ratings. We did those tests in early 2001, and the Energy Star ratings have gotten tighter since then, so the actual ratio now is probably close to even.

According to a Consumer Reports article in the late 90's, the difference ranges from 14% to 40%. Even one of our old 12 year old units with dirty coils and poor seals measured 2.2 times the SunFrost usage - a long ways from the 5 times claimed.

The bottom line: In many situations and systems, it may make more sense to buy a standard energy efficient refrigerator unit and the extra solar panels and batteries required to run it than to buy a Sunfrost. SunFrost has recently come out with an improved compressor that they claim increases efficiency by around 10%. We have little information on it, but some tests done by one of our competitors showed it was more like 5%.

SunFrost states that the refrigerator is the worst energy hog in the home - however according to several US government and private surveys, heating and cooling exceeds it by far - typically around 50% of total usage. All appliances combined take about 30%, water heating around 12%. In a typical home refrigerators and freezers combined use about 11% of the total. To be accurate, the refrigerator might be the major hog in a small off-grid home with propane heating/cooking, low energy lights, and other typical energy conservation methods.

And exaggerated claims of energy efficiency is not the only problem with Sunfrost. Many of the units we saw were poorly built and with very shoddy workmanship. Add to that design flaws that have gone uncorrected for 15 years, and you have a problem. Common problems were gaskets falling off, gaskets turning hard and not sealing, latches breaking and/or falling off, rusted hinges, broken hinges, rusted doors and walls, badly corroded light switches, and flimsy shelves that broke. SunFrost finally corrected the latch problem by offering a retrofit, but it took them almost 15 years.

And we are not alone - below are some quotes from Sunfrost owners from our own email and discussion groups:

I have a Sunfrost RF-19, and it has always had water condensing in the fridge section. It's especially bad in the Summer. I purchased it 5 years ago, and would never buy another one. Recently the latch broke and we held it shut with a bungie cord. I don't think this condensation is an inevitable trade off for efficiency. I attribute it to poor design, with the ineffective door seals.

Do you ever have any problems with water collecting in the bottom of the fridge? Mine has done it from day one. I have an RF-16. I just didn't know if this is a trade off for the efficiency!

They specifically state in their literature that they are quiet. From my conversation with them and your additional input I really don't expect any service from them.  The two year warrantee is garbage.  Their recommendation on the phone to stack acoustical ceiling tiles around the compressor was the first clue I was talking to a Bozo. I would recommend any body considering purchasing a DC fridge to seriously consider the new alternatives that are cropping up.  The (Sunfrost) has been the only real game in town until the last couple of years and I think they have developed a "Were the only game in town" attitude. I wish I had known this before.  I was seriously considering another manufacturer and bought Sunfrost because I thought I'd be getting the best and would have trouble free operation and great service. Fool me once....  Never again.

I'm thoroughly DISAPPOINTED with our SunFrosts. I've replace the gaskets 2 (some 3) times. And still we don't get a good seal.  One of the Freezers runs incessantly. There is always a build up of frost.  (Indicative of air leakage). Half of the catches have broken. I've used the things less than 2 years.  I quit replacing the gaskets with what SunFrost provides. They are just not temperature stable.  SunFrost's gaskets shrink too much in cold, and then leak @ the corners.

 

--- Obviously not everyone will agree with the comments above, but we felt they should be included.

 

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SunFrost may be a good alternative in some situations, we have no problem with that. What we have a problem with is the exaggerated claims. In some cases they are 20 to 45% more efficient than other models - but that is a far cry from the 100% to 400% they claim. We see no reason why SunFrost should not be subjected to the "Truth in Advertising" claims as anyone else. And SunFrost made a lot more sense 15-20 years ago, when most of the ad copy was apparently written - Energy Star was almost unheard of, solar was still selling for over $11 per watt.

One thing to be aware of with ANY refrigerator or freezer, is that when running on a modified sine wave inverter (such as the Xantrex DR, Heart, Statpower (except ProSine), and many others) that the motor efficiency will be from 15% to 25% less due to the waveform from the inverter. (One interesting comment from SunFrost was that they had never tested their units on an inverter, despite marketing them to the off-grid market for many years.) The inverter and/or motor efficiency can be a significant factor, so in many cases you can increase overall efficiency a bit by using a DC powered refrigerator, such as Sundanzer or SunFrost if the battery system is near enough. However, nearly all new home PV systems being installed now are fully wired for standard 120 volts AC, so getting DC to the refrigerator might be a hassle. Also many new systems are being done with 48 volt battery systems, and there are no 48 volt appliances at all that we know of.