Hi; Thanks for the responses. I did not mean to steer the thread off course. I understand all the theroy, I just didn't understand that VA automatically included PFC or crest factor where watts did not. I would have assumed the opposite since watts is based on RMS. Thanks; Thomas Knox
> From: albertson.ch...@gmail.com > Date: Sun, 19 Aug 2012 13:16:08 -0700 > To: time-nuts@febo.com > Subject: Re: [time-nuts] Modern motherboard with RS232 port > > On Sun, Aug 19, 2012 at 12:19 PM, Tom Knox <act...@hotmail.com> wrote: > > > > > Hi Ed; > > I may not have had enough coffee yet, but if Volt X Amps = Watts why would > > there be a difference? > > > That relationship holds for DC but with AC the phase relationship between > voltage and current depends of the complex impedance of the load. If the > load is reactive the phase will not be exactly 90 degrees. When we do the > math inour heads most of us always simplify and don't bother with complex > numbers but in real life impedance is complex. > > But for simple back of envelope calculations we can pretend the power is DC > and just say Volt X Amps = Watts > > Another simple way to know if your PC is going to cost you an arm and a leg > to run 24x7 is to place your hand over the cooling fan exhaust vent if hot > air is coming out you can know for sure that you are paying $$$ to heat > that air > > Even if the PC consumes only 50W that works out to 438 KWH per year at 20 > cents per KWH you can still pay for a new $100 Atom motherboard with the > savings in power and see a profit 2 years. > > If gets worse in the summer if you need to run the AC. Let's say the PC > burns 1W. That dumps 1W of heat into the building and if your air > conditioning runs on a thermostat it will burn a little over 1W to remove > the extra heat. The AC is a multiplier of the power used in the house. > Using this logic someone at work figured out it was cost effective to > trash very old CRT monitor in the building. Same for the light bulbs, we > pay a lot to cool the lighting load. > (I would have simply installed windows that open and saved even more > money.) > > > -- > > Chris Albertson > Redondo Beach, California > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
