On Mon, 2 Nov 2009 09:00:58 -0800, "William Sommerwerck"
wrote:

Its been pointed that you don't really need a watt or watt-hour meter to
save money -- you just turn off things you're not using.

One measurement is worth many guesses. I have 3 kill-a-watt meters.
Very handy.

This is not altogether true.

If it's not all together true, then it must be all apart false.

My electric bill was ridiculous, so I started checking. I'd been too lazy to
regularly turn off my A/V system's equipment, which includes a number of
vampire devices.

Halloween was Saturday, so I'm not surprised that you're still seeing
vampires.

I was surprised to discover that the Parasound controller pulled 30VA, even
when not turned on. And a Lexicon CP-3plus drew 20VA, simply in standby. As
I rarely use it, I turned the standby switch to "off".

Your electric meter measures watts, not VA. If you know the power
factor, you can convert these VA measurements to watts and eventually
to your cost of electricity. The kill-a-watt meter shows both VA and
watts (as well as PF).

Most of the vampire devices are items I don't use regularly. I'm going to
move them to their own strip, so that they will always be off, except when
actually being used.

It's the ones that are left on 24x7x365 that will get you. Borrowed
from one of my previous rants on the subject:

My DirecTV R15-500 DVR burns:
Operating power: 22 watts or 42 VA
Standby power: 21 watts or 40 VA
That's only 8 cents per day or $29/year (at $0.15/kw-hr). Much
better. However, the 0.5 power factor isn't very impressive but it's
under 75w so it doesn't have to comply with EN61000-3-2.

Using the revised numbers, yields:
12.5 watts for the 120GB Seagate hard disk
http://www.seagate.com/docs/pdf/datasheet/disc/ds_barracuda_7200_9.pdf
3.5 watts for my single LNB
Subtracting from the 22.0 watts total leaves:
6.0 watts for everything else including switcher efficiency.
I don't think there's room for much improvement (except for power
factor correction).


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558