how accurate are "energyguide" numbers vs. Kill-A-Watt?

[Nate Nagel]

subject says all...

in an effort to see how much a new fridge would really be worth in terms of energy savings I got a Kill-A-Watt (found one online under $30) hooked it up to fridge. In 24 hours of use it's apparently used almost

2.5 kWh - that's over 900 kWh/year!

I see most of the fridges that I'm considering are rated at about 500 kWh/year give or take.

do both of these numbers seem reasonable? A new 25 ft^3 "energy star" fridge would use a little more than half as much juice as my 20 year old

18 ft^3 clunker?

If this is true, I won't feel nearly so badly about spending the $$$...

nate

[dpb]

Nate Nagel wrote: ...

...

Probably not half, but certainly better. The ratings are only really comparable between rated units for comparison purposes, not in comparison to any specific operating unit, primarily because the testing can't (and doesn't attempt to) mimic the operating cycle of the specific user.

But, since it is the same test, it does have value in comparing units when shopping.

--

[Pete C.]

You need to sample over a good week period to get an accurate figure since the defrost heater is one of the largest consumers, but only runs intermittently. Yes, a new unit will use quite a bit less power overall, and I expect the energy guide numbers are pretty accurate.

[trader4]

I replaced my 24 year old side by side with a new Kitchenaid energy star model last year. According to the energy guide it was supposed to use about $90 a year in electricity. I measured it with a kilowatt meter and it was spot on. I also measured the old one and it was using $185 a year. I performed the test over 3 days with both units. So, in this case, the energy guide is right and I'm saving $95/year, which helps pay for the new unit.

One thing that isn't accurate is the calculator they have at the DOE energy star website. You can put in your old make/model fridge and it will show you how much it's supposed to be using vs what a new one would use. In my case, it said the old one was using like $325 a year, which is way off. I think they may have some calculation factor that assumes a 24 year old has badly leaking door seals and God knows what else to come up with a better scenario.

[ransley]

You will save, I did the same test with a new sears 19.5 frige and KAW meter and I was somewhere near 4.50 a month, a bit better than the yellow tag rating, but I didnt keep doors open long. If its family use and people keep the doors open while shopping for food your rating wont be as good as rated, and your regular use might make it less, but you will still save. When I shopped my decision was only the most efficient unit I could get.

has all ratings, but still check with the Yellow Tag since models vary and there is old stock.

[Ed Pawlowski]

We had a "second" fridge for a few years, an old one given to us. We replaced it with one twice the size and frost free. Electric bill dropped $10 a month. Big improvements since 20 years ago.

[someone]

I know my pretty new Maytag pretty well as I was inside replacing some parts. I know it defrosts once in 8 hours or running. There is a timer that runs only when the compressor runs and after it's run for 8 hours it goes into defrost. If there is not much frost the heater will come on, in most cases, only one time as there is a thermostat that kicks it out when the coil area reaches about 45 degrees. I have had a killawatt hooked up and the amp draw during defrost is about 3 or so amps for a short time, the running amp draw is way down, sometimes around 1 amp.

We replaced an old old unit with this and - true, I sware, light bill went down close to 25 $. The old unit was pre 1969, so there has been lots of progress.

On a side note - one issue with the new units is the running time, they run for a long time, the compressor is SMALL. So, if you were using a generator like during a power outtage to run the thing, it takes a long time to cycle the unit..But - that's not an issue most times.

Gene

[George]

We replaced a similar age old fridge with a new one and there was a significant drop in power use. Also the new fridge has much more uniform temperature throughout the box so you can keep the temp low without freezing stuff. So as a side benefit stuff lasts longer and it is now very unusual to have to discard food.

[HeyBub]

How much did the new unit cost? If, say, $1000, you lose $40/year in opportunity costs (interest on your money). If you had to borrow to buy the unit at, say, 8%, that's $80/year in interest.

To take this concept to a ridiculous extreme, one could spend $50,000 for solar heating, wind turbines, etc., to save an ENTIRE electric bill of $200/month.

Saving money on power usage is good, but, in the view of some, saving money might be way down on the list of reasons.

[Phisherman]

For the most part I trust the accuracy of a kill-o-watt meter. I trust government claims (or anything else for that matter) much less than years ago. Check the refrigerator wall thicknesses when you compare. Refrigerators use a lot of energy.

[Marilyn & Bob]

Consumer Reports had an article recently saying that the Energy Guide (and thus Energy Star) ratings for refrigerators were way off, especially on the side by side ones, because they did not mimic the way most people use the refrigerator. Think the inaccuracy of the old EPA mileage rating system. You will need to use your Kill-A-Watt on your new box to tell your real savings.

[trader4]

$1300. Which is why I said the energy savings of $95/year HELP pay for the cost of the new unit. I actually started looking at a fridge because at 24 years old, it was time for a new one for other reasons. I knew that a new one would save some energy costs, but I was surprised that it cut the electric usage by about 50%. I agree that if you're otherwise happy with what you have, it;s very possible, even likely that you won;t come out ahead by buying a new one. Your best shot at having the energy costs pay for it is probably with an old very basic unit compared to a new similar energy star unit. That way you;re only paying for the essential refrigeration, not ice makers/ water in the door, stainless doors, etc. Even then, it would take a long time.

Also, my energy savings is based on electric cost in NJ, which at around 16cents is among the highest. If you live somewhere that has electric at 11cents, the cost savings/justification are less.

[trader4]

$90 a year for a 24 cft side by side, with ice maker/water in the door is a lot of energy?

[trader4]

In my test done last year with a new Kitcheaid side by side with ice maker/water in the door, the Kill-a-Watt was spot on to the energy guide rating.