Maximum Vs. Typical Wattage for Monitors

W

WeezelDS

n00b
Joined
Feb 2, 2008
Messages
11
Hi all,
I have a hulking 21" CRT ASTVision 20P refurb made in 1997, and I was thinking about how much electricity it sucks down and came up w/ a few interesting numbers. The back of the monitor doesn't say the wattage rating. It says "100-120V/200-240V 50/60Hz, 2.5A/1.5A". So, I figure using the old Watts=Volts x Amps and knowing that american voltage is 110V, this means the monitor is a whopping 275 Watts. Approximating 18 Hrs/Day 330 Days/Year of usage at 11.5 cents per kiloWatt hour, this comes out to about $187 per year. Since new 21" LCDs only need about 50W, if that, I could rationalize getting a new LCD since it would pay for itself in less than two years, if not sooner the way electricity gets more and more expensive.

My question is this: If the maximum wattage rating is 275 Watts, is it always drawing that much power at all times? (assuming it is in use, not in sleep mode). Cuz I heard that monitors use slightly more juice when displaying a white screen as opposed to a black screen, so it sounds like there is some variability. Also, I know that computer PSUs rarely draw anywhere near their maximum wattage rating...Lemme know what you guys think.

Thanks
 
HP w2207 LCD specifications
Power supply type - Internal AC Adapter
Power consumption - 65 watts maximum in operating mode; 2 watts max power saving mode

I have brightness and contrast each set at 60. I plugged in my in-line KillAWatt power meter. It is reading 29W while I am typing this, far less than the max rating. I also previously measured my Dell 19" monitors at work, 25W each. I am not using any speakers or USB ports on the monitor.
 
interesting...thanks for the reply...

however, I wonder if anybody has done this w/ a CRT monitor as they are fundamentally different...also by a contrast of "60", did you mean 60 on a scale 1-100?

Thanks again
 
I do not have a KillAWatt, but according to my ups, at idle with the monitor off I am using 103 watts, with my monitor on 191 watts. So my monitor is using 88 watts while in operation, while posting on this forum. Right at 3 imes the amount of power as najames lcd of similar size. Not sure how accurate the meter on the ups is.

Edit: my monitor is a Viewsonic P220Fb 22" crt.
 
Okay cool, thanks for the info...that seems like a good feeler

Those KillAWatts look pretty sweet...
 
LCDs have their backlight on constantly, so their power draw is more related to brightness, any transient power usage is based on current required to hold the crystals in alignment, so LCDs probably have a much flatter power usage over time and display type. CRTs use an electron beam that is some fraction between off and full on for each pixel on the screen, so there is a much larger difference in power consumption between full black and full white. Even still a LCD at full power is probably going to draw less current than a full black CRT, and just like florescent bulbs, a LCD display will easily pay for itself in 2 years or less I'd imagine. Faster if you're in a warm climate since your AC isn't having to remove an extra 100+W of heat during the summer months while the monitor is going.
 
Its freezing in Pittsburgh right now, so I'm gonna miss the extra heat this thing kicks off in the winter keeping my room warm :\

....also all the stickers it collected all over it after a decade of use

thanks
 
WeezelDS said:
Its freezing in Pittsburgh right now, so I'm gonna miss the extra heat this thing kicks off in the winter keeping my room warm :\

....also all the stickers it collected all over it after a decade of use

thanks
Click to expand...

If you are looking to buy a LCD, you could further offset the cost by selling your crt. I googled your monitor and could not find out if it was an ag tube or not, but I did find a refurbed one for $400 and a new one for almost $1200. You might be able to e-bay or craigslist it for a few dollars. A few dollars more if it is a flat ag screen, provided it works properly and it's case/bezel is not damaged, and you clean the sticker off of it.
 
WeezelDS said:
interesting...thanks for the reply...

however, I wonder if anybody has done this w/ a CRT monitor as they are fundamentally different...also by a contrast of "60", did you mean 60 on a scale 1-100?

Thanks again
Click to expand...

Yes, the w2207 settings are 1-100, default was 90 as I recall and way too bright.

Now look what you made me do. I got out another PC and a 17" CRT monitor. KillAWatt says the 17" is using 64W after a couple minutes on the WinXP logon screen, not running anything at all at this point. This seems to fall right in line with the 88W GORANKAR calculated for the bigger CRT..
 
You must log in or register to reply here.
Back
Top