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Discussion Starter · #1 ·
I would like to thank everyone for the great discussion. I ended up purchasing the LG 50PS60 50" 1080p Plasma. Yes, I know, plasmas are the most inefficient screen, but I got such a good deal that I couldn't pass it up.


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I'm in the process of buying my first nice display, ever. Before now, I've only used computer monitors in my dorms/apartments.


I've been primarily looking at LCD televisions for two reasons: I will be hooking this up to my HTPC and I'd like to avoid burn-in and/or image retention, and also due to their lower power consumption.


I hear that burn-in/IR is hardly an issue anymore, so it comes down to power consumption, which is really just about total cost of ownership over the life of the product. It's been difficult to find any hard numbers on exactly how much power different televisions consume, which is the only way to calculate total cost of ownership.


Here's my dilemma: plasmas produce a better image. Relatively speaking, you can get a much better PQ plasma than an LCD for less money. I have a spreadsheet that will calculate and summarize total cost of ownership over 'x' years if I use the TV for 'y' hours per day...all that's left is for me to plug in the 'watts' values for TVs that I would consider buying.


Is this data available in an easily searchable format, or must I wade through individual product reviews, hoping that they measured power consumption (and did a good job of it).
 

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Discussion Starter · #3 ·

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Originally Posted by aim120 /forum/post/17012912


this should help http://www.digitalversus.com/duels.p...&p2=4245&ph=16 choose a make,model and the test which includes contrast ration,motion handling and enery use.usualy a easy victory for newer lcds from sony and samsung.

I don't know if it's because I'm in the US, not the UK, but all I see are blank images for the energy test for all those displays.
 

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Quote:
Originally Posted by panfist /forum/post/17014389


I don't know if it's because I'm in the US, not the UK, but all I see are blank images for the energy test for all those displays.

well european and US models would have the same power consumption,not all models have the energy results,but you can get a general idea about the difference in power consumption.
 

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One cannot accurately calculate the cost of ownership without stating the configuration values.


For an example, the 46B750 I reviewed consumes around 105W (post-calibration). However, by default, it consumes around 221W.

http://www.hdtvtest.co.uk/news/samsu...0090526151.htm



With plasma, the consumption rate varies according to the displayed image. So one would have to measure power consumption of 0IRE and 100IRE and average it out.
 

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In fact the cost of running the HDTV is almost irrelevent if you live in a warm climate and use an air conditioner to cool your home. The air-to-air heat exchanger type of A/C (the most common type by far) has a thermal efficiency of only about 27%. That means a 200w HDTV will use an average of 741w to cool the room it's in, and running the HDTV and the A/C both consume 941w average.


I stress that's an average figure. The A/C uses lots more power and the compressor cycles on and off at a rate that depends on total heat load, total temperature drop versus the outside air, and other factors like cooling duty cycle and ambient heat gain (which depends upon roof color and insulation values). In fact there are so many factors that (although the caluculation can be made), the bottom line is that in a room with A/C in use, what look like fairly minimal power consumption differences become 3-4 times as large as the HDTV power alone. But you also have to know things like the duty cycle of the A/C, number of cooling days in the season, etc. Which information I happen to get from my home automation computers and network of sensors (hey, I'm an engineer and I've been recording this data for years).


In a recent home remodel I switched over from incandescent room lighting to high efficiency flourescents with digital dimmers. I saved enough total power (considering cooling) that even though I have added two medium sized flat panels, there is still a net power savings and my A/C compressor comes on less often and shuts off sooner. I also saved enough power to run my three large aquariums by ducting the radiator heat on back of the refrigerator outside the house. I only have four wastefull incandescent bulbs left in the whole house, in Tiffany stained glass fixtures that the wife won't let me touch....


The surprising thing is that even after considering the State and Federal tax benefits and credits and assuming that electric rates will increase 100% per decade (which I think is conservative in a state which gets electrical power from mostly oil and natural gas, and after "peak oil"), you can't justify putting solar panels on the roof. But conservation has a shorter payback and makes all kinds of sense.
 

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Discussion Starter · #7 ·

Quote:
Originally Posted by Nielo TM /forum/post/17018959


One cannot accurately calculate the cost of ownership without stating the configuration values.


For an example, the 46B750 I reviewed consumes around 105W (post-calibration). However, by default, it consumes around 221W.

For my purposes I'm assuming that I am calibrating the display. Not doing so is just plain stupid. On the other hand, I just need more and more data. Before I started doing this research, I had zero hard information on wattage levels of different TVs. The more information, the better, even if it's incomplete or just averages.


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Quote:
Originally Posted by Gary McCoy /forum/post/17019240


In fact the cost of running the HDTV is almost irrelevent if you live in a warm climate and use an air conditioner to cool your home.

Based on the rest of your post, I wouldn't say that the cost of running an HDTV is irrelevant..in fact i would say that any calculations you make for cost of running an HDTV would be a very sensitive indicator for your overall energy costs (if you use air conditioning, which I do for half the year). It's a sensitive indicator because any potential costs/savings are amplified by the fact that your A/C is so inefficient.

Quote:
Originally Posted by Gary McCoy /forum/post/17019240


In a recent home remodel I switched over from incandescent room lighting to high efficiency flourescents with digital dimmers.

You mention things like replacing incandescents with fluorescents, but really that's clouding the issue; changing light fixtures in a home is totally independent of what types of TVs you have and how many.


I just ordered 20 CFLs and 10 dimmable CFLs to replace the incandescents that came in all the light fixtures in the house. Here's a question out of left field...has anyone considered swapping CFLs and incandescents seasonally? Does it make sense to use an incandescent during the winter, when the "wasted" heat energy actually helps heat your home, saves working life of your CFLs, and provides you a higher quality light during a season when you're using your light bulbs longer per day?


Quote:
Originally Posted by Gary McCoy /forum/post/17019240


But conservation has a shorter payback and makes all kinds of sense.

I totally agree.


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I found this chart on CNET:

http://reviews.cnet.com/green-tech/t...umption-chart/


I'm not sure how much I trust cnet, but based on this chart I'm looking at getting either the Samsung LN46A550 (which I can find for $975) or the Sharp Aquos LC-52D65U (which I can find for $1250). It depends on how much cheese the misses is willing to cut...
 

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One thing that calculating ownership costs will miss is the enjoyment factor.


Buying the cheapest to operate set may negatively impact your enjoyment gained using the set to where it becomes even cheaper to operate, because you don't enjoy watching it.
 

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Discussion Starter · #9 ·

Quote:
Originally Posted by aydu /forum/post/17020234


One thing that calculating ownership costs will miss is the enjoyment factor.


Buying the cheapest to operate set may negatively impact your enjoyment gained using the set to where it becomes even cheaper to operate, because you don't enjoy watching it.

This is possibly the dumbest thing I've read on this forum. The 'S' in AVS stands for science. It's not 'P' for Psychology, or Pseudoscience.


Calculating the total cost of ownership is just one piece of information that fits into many dozens of variables that influence which display I will get. If I was concerned with "cheapest to operate" only and nothing else, then I wouldn't buy a TV because the cheapest TV to operate is no TV at all.
 

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No, I don't think seasonal swapping of CFLs for incandescent lighting makes sense. It is true that the less efficient lighting will reduce your need for heat, but you would be substituting heat from your furnace (probably relatively efficient gas) with heat from what amounts to electric resistance heaters (Edison light bulb filaments). If your main heat is more efficient heat pump electrical, you are still substituting electric resistance heat for a more efficient form.


In general, even after the recent improvements, plasmas reject more heat than LCDs. The least efficient sets you can buy are the commercial plasmas with oversized power supplies. The most efficient are the LED backlit LCDs. But if you can subdue the room lighting and reduce the brightness of the plasma or the backlight setting on the LCD, you can considerably reduce power consumption on either set type.


I calibrated both my LCDs twice, once of brighter daytime use and once for night. I used the "viewing mode" options on the Samsung for those - daytime is "Standard" mode and nighttime is "Movie" mode. I found that the third setting or "Dynamic" mode could not be properly calibrated - it boosts both white levels and black levels in bright scenes, then reduces both white levels and black levels in darker scenes.
 

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Quote:
Originally Posted by panfist /forum/post/17020313


This is possibly the dumbest thing I've read on this forum. The 'S' in AVS stands for science. It's not 'P' for Psychology, or Pseudoscience.


Calculating the total cost of ownership is just one piece of information that fits into many dozens of variables that influence which display I will get. If I was concerned with "cheapest to operate" only and nothing else, then I wouldn't buy a TV because the cheapest TV to operate is no TV at all.

And where are all these scientific calculations of the dozens of variables being done?


If it ain't Excel, you're into the "P" words.


All science in these sets ends with the interface with the human being. Unfortunately for lovers of pure scientific conlcusions, the human being is the most variable link in the chain. That is why, despite scientific people evaluating things endlessly, there are multiple brands of things.


The cheapest tv to operate is the one that uses the least power and obtains that power from the lowest cost source.


P.S Not trying to disprove my dumbness, just trying to help you set a new personal record for dumb things read on this forum.
 

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Discussion Starter · #12 ·

Quote:
Originally Posted by aydu /forum/post/17025531


And where are all these scientific calculations of the dozens of variables being done?


If it ain't Excel, you're into the "P" words.
Quote:
Originally Posted by panfist /forum/post/17012788


I have a spreadsheet that will calculate and summarize total cost of ownership over 'x' years if I use the TV for 'y' hours per day...all that's left is for me to plug in the 'watts' values for TVs that I would consider buying.

Most of the variables that go into my decision aren't exactly quantifiable, for example is the PQ of this model worth the extra money compared to this cheaper model with a lower quality picture? But for those variables which are quantifiable, like power consumption, I would like to gather as much information as I can before I make my decision. If I quantify as many variables as are reasonable to quantify (for example power consumption, contrast ratio, brightness, inputs, cost) then I can eliminate as much of the subjective as possible from my decision.


The thing that you said which I found ridiculous was your assumption that I would automatically chose to purchase the cheapest-to-operate set after I had done the calculation, and that my enjoyment would be lowered because I had done the research.


Multiple brands doesn't even enter into this discussion. There are multiple brands for many reasons...market segmentation probably being the most influential reason. There are other reasons, for example building a television is only partly a scientific problem. It is mostly an engineering problem. You can't build an ideal television because you don't have ideal components. You have design constraints. You have to cut corners to save costs. Sony's engineering team will certainly cut different corners and adhere to different design constraint's than Samsung's team; both engineering teams are working towards building an ideal display, but the result is a real-world implementation of a non-ideal display. Because of their different design parameters, you get displays with different characteristics and costs.
 

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Discussion Starter · #13 ·

Quote:
Originally Posted by Gary McCoy /forum/post/17022106


No, I don't think seasonal swapping of CFLs for incandescent lighting makes sense. It is true that the less efficient lighting will reduce your need for heat, but you would be substituting heat from your furnace (probably relatively efficient gas) with heat from what amounts to electric resistance heaters (Edison light bulb filaments). If your main heat is more efficient heat pump electrical, you are still substituting electric resistance heat for a more efficient form.


In general, even after the recent improvements, plasmas reject more heat than LCDs. The least efficient sets you can buy are the commercial plasmas with oversized power supplies. The most efficient are the LED backlit LCDs. But if you can subdue the room lighting and reduce the brightness of the plasma or the backlight setting on the LCD, you can considerably reduce power consumption on either set type.


I calibrated both my LCDs twice, once of brighter daytime use and once for night. I used the "viewing mode" options on the Samsung for those - daytime is "Standard" mode and nighttime is "Movie" mode. I found that the third setting or "Dynamic" mode could not be properly calibrated - it boosts both white levels and black levels in bright scenes, then reduces both white levels and black levels in darker scenes.

Isn't the heat due to electrical resistance basically a perfect transfer of energy? A filament light bulb dissipates a certain amount of watts, some of which is converted to visible light, and the rest is converted to heat and light in other parts of the electromagnetic spectrum. Infrared light from the bulb will be absorbed as heat by whatever's in its path, and the rest of the heat will be absorbed conventionally through the air. Is it less efficient because of the way humans perceive the heat? There is probably something else I'm missing, but it's really a discussion for another time and place. I am curious, though...


I'm hoping to calibrate my displays with a Spyder calibration tool, but it's designed for computer monitors, so I don't know how good my results will be.


As far as dynamic contrast goes, I will have to test it out on my display, because as far as I know it involves modulating the backlight uniformly in response to what's being displayed on the screen. It seems like each manufacturer's implementation of this would be different; some might be better than others, and it's probably all up to personal preference. I have this feature on one of my computer monitors, and I don't use it because of what you described.


This discussion is all moot anyway, because I ended up purchasing the LG 50PS60 50" plasma that popped up on slickdeals yesterday. In turned out to be ~ $800 after all the discounts; I think that even if I could possibly include all the hidden costs associated with the extra power consumption, this TV was the best deal I could get at the time.
 

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Quote:
Originally Posted by Gary McCoy /forum/post/17022106


No, I don't think seasonal swapping of CFLs for incandescent lighting makes sense. It is true that the less efficient lighting will reduce your need for heat, but you would be substituting heat from your furnace (probably relatively efficient gas) with heat from what amounts to electric resistance heaters (Edison light bulb filaments). If your main heat is more efficient heat pump electrical, you are still substituting electric resistance heat for a more efficient form.


In general, even after the recent improvements, plasmas reject more heat than LCDs. The least efficient sets you can buy are the commercial plasmas with oversized power supplies. The most efficient are the LED backlit LCDs. But if you can subdue the room lighting and reduce the brightness of the plasma or the backlight setting on the LCD, you can considerably reduce power consumption on either set type.


I calibrated both my LCDs twice, once of brighter daytime use and once for night. I used the "viewing mode" options on the Samsung for those - daytime is "Standard" mode and nighttime is "Movie" mode. I found that the third setting or "Dynamic" mode could not be properly calibrated - it boosts both white levels and black levels in bright scenes, then reduces both white levels and black levels in darker scenes.




I own 4 Panasonic plasmas myself. I own a 58" 2 50" and a 42". I noticed the electricity costs rise. I noticed my rooms felt like ovens
. Then started to investigate the electricity use between them and was shocked. The 58" plasma with an Onkyo receiver, a 2500 proamp etc.. would easily hit 1000-1300 watts while watching movies. The longer I watched the hotter the room felt and I would have to run upstairs to turn the a/c lower. I live in Florida and it is hot and humid here so these plasmas make a heat difference for me. I ran out and bought 3 LED Tv's and while i sacrificed some PQ quality in one area I gained in the next. I am not a picky Avid tv watcher because then I would not enjoy watching movies. I can say the power consumption is big and my room do not get hot where I put the LED's in. This is my personal experience so don't attack me
.
 

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Quote:
Originally Posted by panfist /forum/post/17026644


Isn't the heat due to electrical resistance basically a perfect transfer of energy? A filament light bulb dissipates a certain amount of watts, some of which is converted to visible light, and the rest is converted to heat and light in other parts of the electromagnetic spectrum. Infrared light from the bulb will be absorbed as heat by whatever's in its path, and the rest of the heat will be absorbed conventionally through the air. Is it less efficient because of the way humans perceive the heat? There is probably something else I'm missing, but it's really a discussion for another time and place. I am curious, though...


-snip-

The calculation of efficiency gets a little slippery depending upon the boundaries you define for the "system" you are calculating. Electricity costs far more per thermal unit than does gas - to the end-user.


For example, common natural gas furnaces often have a thermal efficiency in the mid eighty percent range. Since you burn the fuel in your local furnace and use the heat directly, that eighty-something percent figure is also the overall thermal efficiency of your heating system.


But the fuel for electrical power is typically coal, burned remotely at something like 46% thermal efficiency for the power itself, and a little higher if the waste heat is also used for space heating (cogeneration). For example the campus at my Engineering school had it's own power plant, and the waste heat was sent through underground tunnels in steam pipes and heated every campus building.


But the 46% efficiency is the killer, and the reason that electric resistance heating costs about 2.5 times what gas costs for electric space heating, per thermal unit. So even if the resistence heating efficiency is 100%, the cost per thermal unit is greater.


But in a heat pump you use the electricity to move existing heat from the outdoors inside your building. If you just consider the equipment in your house, the efficiency looks really high, perhaps greater than 100%. But the cost of the electrical fuel is so much higher than natural gas that overall even the more efficient electric heat pump heating costs more than gas.


The trend is the wrong way too - dirty coal power plants are shortly to be burdened with the extreme carbon credit costs imposed by CCT (Carbon Cap and Trade) legislation. So electricity is going way up in cost. Gas also gets CCT "taxes" but it is much cleaner than coal (i.e. spews less carbon per thermal unit), so the impact to final cost from CCT is less.


Air conditioning an enclosed space with an air-to-air heat exchanger type heat pump approaches the least efficient system one can imagine. Basicly you start with the most costly "fuel" (i.e. electricity) and then run the lowest efficiency heat pump design (air-to-air heat exchange) to move around heat generated by more electricity (light bulbs, HDTVs, appliances, etc.). That's why A/C is so environmentally unfriendly - unless your electricity is produced by renewable sources (wind and solar) or nuclear or hydropower or geothermal (i.e. without burning fuel). That's also why "Green" homes often have natural A/C (underground construction or green roofs or water-flooded roofs).
 

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Discussion Starter · #16 ·

Quote:
Originally Posted by Gary McCoy /forum/post/17027008


The calculation of efficiency gets a little slippery depending upon the boundaries you define for the "system" you are calculating. Electricity costs far more per thermal unit than does gas - to the end-user...

That was very informative, thanks.
 

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Quote:
Originally Posted by panfist /forum/post/17026575


The thing that you said which I found ridiculous was your assumption that I would automatically chose to purchase the cheapest-to-operate set after I had done the calculation, and that my enjoyment would be lowered because I had done the research.

No desire to offend or make assumptions about you or your actions. To be honest, I don't think a consumer can make a bad decision on any HDTV that they choose to purchase, as any set will deliver a picture quality that exceeds what we have ever had in our homes.


I was just attempting to point out that when we take one specific factor and give it too much weight in the decision making process, we can all end up with less than a good decision.


I personally find that pq is the dominant factor in selecting an HDTV. Other factors, such as the appearance of the set; the sound quality; and brand reliability are things to consider, but I would not buy a set with what I consider poor pq regardless of these other issues.


Same with power consumption. Less is better, but not at the sacrifice of pq.


I recently was in the market for a car. I had one model picked out, reviews were excellent, and gas mileage was within the range I was looking for. After test driving the car, I found the seats to be very uncomfortable.


I made the decision that I would give up all the other excellent qualities of this car due to the fact that the seats didn't fit mine.


If power consumption; connection number and types; bezel design; or any combination of factors make this a good choice for you, that is excellent.


If it all adds up, but does not deliver on your primary area of interest, the secondary factors, to me, would not offset underachieving in the area that I find most important.
 

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I agree with the above statement. One of the most important aspects of satisfaction with your purchase includes indulging your preferences. If you prefer LCD or Plasma technology, buy what you like. If your perception of quality includes reduced power consumption, then satisfy that requirement. But in any case, do not miss the satisfaction that comes from indulging your preferences in an expensive luxury purchase like a flat panel HDTV.
 

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Quote:
Originally Posted by Gary McCoy /forum/post/17019240


In fact the cost of running the HDTV is almost irrelevent if you live in a warm climate and use an air conditioner to cool your home. The air-to-air heat exchanger type of A/C (the most common type by far) has a thermal efficiency of only about 27%. That means a 200w HDTV will use an average of 741w to cool the room it's in, and running the HDTV and the A/C both consume 941w average.

Gary,


There is a fundamental error in your calculations on the amount of power required to remove the heat produced by a plasma TV.


From http://en.wikipedia.org/wiki/Thermal_efficiency , the efficiency of an unattainable, ideal, reversible heat engine cycle called the Carnot cycle is 1 - Th/Tc = (Th - Tc)/Tc. Since the ideal heat engine cycle is reversible, this limit applies to air conditioners as well as generation of electricity from heat. For cooling, the input and ouput are reversed, yielding an upper limit of Tc/(Th - Tc).


In the case of an air conditoner pumping heat from a 70f room to a 100f outside temperature, the limit is (first converting Fahrenheit to Rankine), (70 + 459.67)/(100 + 459.67 - 70 - 459.67) = 17.65. If the air conditioner has a thermal efficiency of 27%, the COP (Coefficient Of Performance) is .27*17.65 = 4.77. This means 4.77 watts of heat is removed for every watt of electricity used by the air conditioner. In the case of a TV dissipating 200 watts, an extra 42 watts of electrical power will be needed to remove the heat.


Air conditioners are usually specified by EER (Energy Efficiency Ratio). EER = (cooling energy in Btu/hr)/(power consumption in Watts). 1 Btu/hr = .293 watt so if an air conditioner has a EER of 12, the COP is 12 * .293 = 3.52. In this case, 57 watts of electrical power will be needed to remove 200 watts of heat.


Daniel Lang
 

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Discussion Starter · #20 ·

Quote:
Originally Posted by dblang /forum/post/17043252


Gary,


There is a fundamental error in your calculations on the amount of power required to remove the heat produced by a plasma TV.


From http://en.wikipedia.org/wiki/Thermal_efficiency , the efficiency of an unattainable, ideal, reversible heat engine cycle called the Carnot cycle is 1 - Th/Tc = (Th - Tc)/Tc. Since the ideal heat engine cycle is reversible, this limit applies to air conditioners as well as generation of electricity from heat. For cooling, the input and ouput are reversed, yielding an upper limit of Tc/(Th - Tc).


In the case of an air conditoner pumping heat from a 70f room to a 100f outside temperature, the limit is (first converting Fahrenheit to Rankine), (70 + 459.67)/(100 + 459.67 - 70 - 459.67) = 17.65. If the air conditioner has a thermal efficiency of 27%, the COP (Coefficient Of Performance) is .27*17.65 = 4.77. This means 4.77 watts of heat is removed for every watt of electricity used by the air conditioner. In the case of a TV dissipating 200 watts, an extra 42 watts of electrical power will be needed to remove the heat.


Air conditioners are usually specified by EER (Energy Efficiency Ratio). EER = (cooling energy in Btu/hr)/(power consumption in Watts). 1 Btu/hr = .293 watt so if an air conditioner has a EER of 12, the COP is 12 * .293 = 3.52. In this case, 57 watts of electrical power will be needed to remove 200 watts of heat.


Daniel Lang

This is why I love avsforum.
 
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