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#1 Guest__*

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Posted 23 August 2005 - 03:10 PM

Dear all,

What do you think about this company???
It's name is energy smart....
http://www.eslainc.com/

Best regards,
Nicos

#2 marke

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Posted 23 August 2005 - 06:59 PM

Hello Nicos

The Power planer has been around for quite a while. We see it referred to occasionaly, but I am not in a position to comment on the company itself.
I would however suggest that you read my paper on energy savers and induction motors at http://www.LMPhotonics.com/energy.htm The major issue is not the company, or the technology, rather that there is little energy wasted so even less that can be saved.
The induction motor is inherently efficient down to light loads and will only save energy when it has a very light load, but that is small in KW. The issue is that there are very few applications where the "OFF" load is light enough for the motor efficiency to fall to the point where energy can be saved. The energy that you can save is a portion of the iron loss and on modern motors this amounts to around one third of the full load losses of a motor. If you have a motor that is 90% efficient at full load, then there are 10% losses. The iron loss may be in the order of 3% and if you can save 50% of the iron loss, you will save about 1.5% of the motor rating, but this will only occur whne the motor is under open shaft conditions. As the load is increased, the energy that can be saved is reduced.

Dont look too hard at the suppliers, look at the motors first.

Best regards,

#3 jraef

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Posted 23 August 2005 - 07:00 PM

Hello Nicos,

I have seen this product in 2 installations here in the US. In both applications, they were disconnected (bypassed) because they created more problems than they solved. This is just anoher re-hashed version of the old Nola circuit again. It uses SCRs to phase back the voltage on UNLOADED motors so that there is less iron loss. No magic here, just the same old thing that has been done for 30+ years by lots of other people. The survivors in that business made it because they discovered that the way to sell them was as a soft starter, not an energy saver.

The concept doesn't really work as well as they claim, so peoplelike them rely upon finding uninformed customers who buy based soley on "testimonials" rather than on hard facts. If you go through their website carefully you will notice that they do not have any detailed description of how it actually works!

I did notice that they have changed their wording to be a little more careful (compared to others I have sen), likely as the result of problems with their claims. They say "Reduces the power consumption of unmatched motor systems". The key there is that they have added the word "unmatched", which I suppose means that the motor is much bigger than necessary for the application. That is likely a way for them to dodge the eventaul complaints when customers don't see any appreciable savings. They can claim the motor was too closely matched!

Read Marke's paper on this subject. This type product is exactly what he is referring to.
"He's not dead, he's just pinin' for the fjords!"

#4 Guest__*

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Posted 03 October 2005 - 11:15 PM

I just used a device called Kill-a-Watt (on loan from our regional energy office) that measures watts used over time and measured a washing machine and a dryer using the Power Planer and not using it. The usage on the washing machine waw 290 watthours with the Power Planer vs 350 watthours without. On the dryer it was 336 watthours vs 400 watthours without. This is a 15-17% savings. I ran several loads and the results were almost identical. I am not expert but this seems significant. Could it be that washers and dryers run more unloaded and so the device is more likely to be effective? Glen

#5 marke

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Posted 03 October 2005 - 11:51 PM

Hello Glen

Those figures sound low to me.
My washing machine draws around 1KW and my dryer draws 1.8KW. It depends how long you ran the units for.

If these figures that you quote are acurate,then yes you have a saving, but you must ensure that the drier operates for the same time to achieve the same results. If you reduce the voltage to the drier, the elements will produce less heat and it will require a longer time to dry the clothes. You will only save total energy use on the motor.

Assuming that these figures are correct, and that the units operate for one hour each day, then your total consumption for one year would be 127KWHrs for the washing machine and the saving would be 22 KWHrs (22 units) If you pay say $0.20 per KWHR, this would be a saving of $4.38 per year. What is the cost of the power planner??

Best regards,

#6 jraef

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Posted 05 October 2005 - 07:01 AM

I question those figures as well. My blender uses more than 290 watts. Also, all the Kill-a-Watts I have seen are only for 115V plug-in appliance loads, not big things like electric dryers. Unless it is a gas dryer, and then you are only looking at the motor load. Mine has a 1/4th HP motor, about 187W, and the biggest ones I know of are 1/3HP, or 250W so that doesn't fit either. If your numbers were off by a factor of 10, they still wouldn't fit the typical scenario because neither appliance uses that much power.

Marke is absolutely correct, if you reduce the voltage on electric heating elements they produce less heat so your clothes take longer to dry. End of story, there is no magic device that makes heating elements produce more heat with less energy. I cannot see how that device then would end up saving energy on an electric dryer. On a washing machine, it may possibly run in unloaded cycles more often than not. It's possible that the motor is sized for the worst part of the cycle, the spin cycles when the tub is full of wet clothes after the pumping is done. The agitation and pumping cycles may not require as much motor power, and the spin cycles may be less loaded as the water is extracted so that may account for a moderate savings I suppose. Still, $4.38/year is hardly worth fussing about. You can save more money than that by just washing bigger and fewer loads.
"He's not dead, he's just pinin' for the fjords!"

#7 bob

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Posted 06 October 2005 - 04:45 AM

Hi all,

I agree that the so-called energy saving devices do save energy but the result is only marginal and most of the times does not worth trying.
But what about high efficiency motor ?
Bearing in mind that the efficiency of common motors are around 90 % at full load, this means that only 10 % of the losses( iron and copper ) could be saved.The cost of investment and the saving should be compared thoroughly before embarking on high efficiency motor.

Bob

#8 jraef

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Posted 06 October 2005 - 07:40 PM

QUOTE
Originally posted by bob
... The cost of investment and the saving should be compared thoroughly before embarking on high efficiency motor.

Bob


Yes, and you should apply that to any energy saving technique. The cost benefits of going to ES motors are generally based upon long operating time and slightly increased efficiency. Going from 90% to 95% efficiency can save a lot of money if the motor runs all day long, but that is insignificant if it only runs a few minutes per day.
"He's not dead, he's just pinin' for the fjords!"

#9 Guest__*

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Posted 27 October 2005 - 09:09 PM

Gentlemen, if you will re-read the post of "Anonymous " above you will see that the energy values he reported are Watt-Hours not Watts. The dryer he reported on is almost certainly a gas drier because 1) the Kill-a-Watt meter operates on 115V only (in the USA), and 2) an electric dryer would use much more than the measured 400W-hr's. This means the measured power use for both the washer and dryer are mostly for the drive motors.

He reported hard data taken on actual devices. That seems quite valuable to me in deciding if these Power Planner devices actually work. Reading all of the postings above it seems that they do and this is because most home appliance motors are more powerful than required, and so "unmatched".

Assuming the washer and dryer perfomed their functions well the Power Planner looks useful and we should consider if the benefits are worth the costs.

As stated above the power savings on a washer or (gas) dryer seem unlikely to justify a $40 device unless there is some other benefit.

The Power Planner's makers claim to improve product life span by running the motor at lower voltage and so lower temperature. Does anyone have any quantitative information on this?

I have used a Power Planner on my refrigerator and can attest to the reduced noise from the compressor when using the Power Planner. In my quiet house with the living room open to the kitchen I'd pay $40 for that alone.

I'm considering buying two more units for my freezer and old refrigerator in the basement.

They each consume about 600 kW-hr per year at 10 per kW-hr so $60/year each. If the Power Planner saves 15% that would be $9 per year and would pay for the $40 device in under 5 years. It's not fantastic but certainly not a silly investment.

The major unknown for me is how the Power Planner would actually effect product life. If it actually doubles the life of a $500 appliance from 10 to 20 years that's worth a lot mroe than the power savings.

Jeff Hamilton

#10 jraef

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Posted 28 October 2005 - 07:49 AM

QUOTE
...this is because most home appliance motors are more powerful than required, and so \"unmatched\".


Jeff,
There is the flaw in the argument. Where are you, or they, getting that information? Why does anyone assume this to be the case? Simple economics states that an OEM would apply no more motor than they have to for an appliance, to do so would be a waste of money. Having sold motors to appliance manufacturers, I can attest to that. Believe me, if they need 1/12HP, they do not just go out and buy a 1/8HP motor and slap it on. In fact, since a standard 1/16th HP motor is too small, they would likely have motor mfrs quote on a custom 1/12th HP motor rather than buy a 1/8th.

And by the way, he did not say KILO watt hours, he said WATT hours, and the point I was making was that 290 WATT hours would be no more than running my 290w blender for an hour. Even a gas dryer tumbler motor is going to use a lot more than that. On top of that, the ONLY way that device could possibly save energy on a gas dryer tumbler motor would be if the dryer were empty. Why would you run the dryer empty?

I bought a new refrigerator. I cannot hear it running when I stand right next to it, and it uses 1/2 of the energy of it's predecessor. That has nothing to do with magic boxes on the wall. Reducing the voltage on a compressor motor would have no effect on the sound pressure emitting from it unless it were to slow it down, and that could seriously damage it. You may be experiencing a case of wishful thinking. You already spent the money on it, so you hear what you need to hear in order to justify the expenditure. Put a db meter on it and show me the change in numbers, then I'll believe it.
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#11 marke

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Posted 28 October 2005 - 10:20 AM

Jeff, if you are happy with the device, that is great. There certainly are situations where it will achieve a worthwhile result, but there are also many claims about the technology that can not be supported by repeatable tests.
It is commonly claimed that if a motor is oversized, it is wastin energy. This is not the case. Have a look at the efficiency curves for a motor and you find that the motor is commonly most efficient at around 75% load, and as the motor sizes increase, their efficiency increases also. A 100KW motor operating at 75% load (75KW) can often be more efficient than a 75KW motor at full load>

Study the motor curves, do your own tests and if it works out for you, that is great.

Best regards,




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