Power consumption of some domestic applicances

Following on from the more detailed measurements of input current to some computing equipment and low-energy lamps, I felt like having a better idea of how much is wasted by several always-on appliances, as well as some `which should I use' loads such as microwave and conventional ovens.

Measurement by an oscilloscope, with current and voltage probes, is time-consuming compared to a simple plug-in power meter, although the simple meter gives no detail of the harmonic spectrum. Such a meter was used for the following measurements: its details are `Everflourish EMT707CTL ref:36.2897', and it has been tested against an oscilloscope measurement, from which it was found to calculate P and Q correctly, which is not always so for such meters (see the meters test in the it_power page).

Much of the remainder is in plain text form, as I keep such notes in this way and don't see much advantage to spending time making an html table.

Kitchen things

The fridge and freezer were not included, due to poor accessibility of their plugs and sockets, and to their intermittent nature (long-term energy measurements would be needed, to find the duty cycle, if wanting the mean consumption). Based on sust-it.net, `larder fridges' are about 140 -- 170 kWh/year. and `upright freezers' about 220 -- 380 kWh/year. So, total for our separate, tall, fridge and freezer may be from about 40 to 60 W, mean combined power.

The consumption of elements on an electric cooker is easily found from manuals. Ours (Electrolux CF 161 B) takes from 1.0kW to 1.9kW for the hotplates, and about 1.8kW for the basic oven (top and bottom heaters, not the extra grilling element) when on full. When the rings are turned below the full setting, it's not obvious how linearly the reduction in duty cycle (proportion of time for which the element is on) relates to the number shown on the switch -- I've never tried testing this.

To get a rough idea of the warm-up energy and the steady-state power consumption of the oven, I timed its warm-up and the duty-cycle when at 200 degC.

Warming up from room temperature, empty:
        time(mins)  temp(degC)
          0		 20
          5		100
          7½		150
         10		200

On reaching 200 degC, the cycle of the empty oven was about 180s on and 400s off, i.e. on for about 0.3 of the time: the mean power consumption (mean heat loss) is therefore about 600W (when empty).

The following are a few more kitchen things whose consumption I measured:

Kettle (rated 2.5--3.0kW [220--240V])
	on			2500W

Coffee-percolator (small)
	on			 430W

Food mixer (no mechanical load)
	lowest			  60W	  68VA
	highest			  96W	  96VA

Kitchen extractor fan
	I			  29W	  31VA
	II			  31W	  32VA
	III			  55W	  64VA

Microwave oven (Philips Whirlpool VIP27, fairly old)
	1000W-setting		1750W	1890VA

Miscellaneous domestic things

Clavinova CLP-130 (electronic piano-substitute)
	off			   0W	   0VA
	on			  16W	  28VA

Stereo system (Technics SAX800L, integrated amp, tuner, cassette)
	off			   0W	   0VA
	on, radio		  20W	  28VA

Cordless phone base-unit
	phone in place, idle	   2W	  13VA
	phone out, in use	   2W	  13VA

Mobile-phone charger (Nokia, c.2007)
	without phone		   0W	   0VA

Uniross battery charger (model CXH3: 4x(AA|C|D))
	empty			   2W	  10VA
	charging (4x AA)	   5W	  14VA

Computer equipment

VOIP phone adaptor box (for a Tele2 `internet telephony' account)
	running			   4W	  18VA

Ethernet switch (Netgear gigabit 8-port switch)
	running			   7W	  16VA

Wireless router (D-link DI 524: wireless[b|g] plus 4way hub)
	running			   6W	  18VA

Laptop computer (Dell Latitude X200, 800MHz, with CPU scaling)
	adaptor alone		   1W	  10VA
	sitting idle		  17W	  42VA
	playing video (~80%CPU)	  24W	  55VA

Laptop computer (Dell Latitude C840, P4mobile 1.8GHz, scaling)
	adaptor alone		   1W	  10VA
	sitting idle		  40W	  42VA
	playing video		  60W	  61VA

Laptop computer (Toshiba Portege, 7100 series, ~450MHz)
	adaptor alone		   2W	  11VA
	sitting idle		  31W	  62VA
	full cpu		  37W	  72VA

Desktop computer (AMD Duron CPU, 800MHz, 1 disk)
	sitting idle		  66W	 130VA
	full cpu		  80W	 150VA

Desktop computer (Dell, with PIII 500MHz, 1 disk)
	off			   2W	  11VA
	sitting idle		  33W	  67VA

Desktop computer (IBM-6569-NAG, PIII 800MHz, 1 disk)
	off			   2W	  11VA
	sitting idle		  30W	  61VA
	full cpu		  53W	 102VA

Desktop [`Workstation'] computer (Sun Ultra60, 2CPU 450MHz, 2 disk)
	off			   2W	  21VA
	sitting idle		 168W	 186VA

Laser printer (HP1018, a small b&w one)
	idle			   3W	  11VA
	starting job		 570W
	during first page	 360W

Scanner (Epson Perfection 1670)
	adaptor alone		   0W
	idle			  11W	  25VA

Monitor (CRT: Sun GDM-5410 [Sony] 21")
	plain VGA console	  85W
	`normal'		 112W	 118VA
	very black window	 102W
	very white window	 136W

Monitor (CRT: Compaq MV720)
	on, computer off	   6W	  16VA
	`normal'		  58W	  96VA

Monitor (CRT: Samsung SyncMaster 15 GLI)
	standby			   4W	  12VA
	`normal'		  67W	 150VA

Monitor (LCD: Samsung Samtron 51S, small)
	off			   1W	  10VA
	on, computer off	   1W	  10VA
	`normal'		  24W	  48VA

Computer speakers (Small Dell ones)
	off			   2W
	on, inactive		   2W
	on, active		   3W	  14VA

Computer speakers (small, cheapo)
	off			   1W	  12VA
	on, inactive		   2W	  12VA

Computer speakers (Harman Kardon, c.2000)
	off			   2W	  15VA
	on, inactive		   4W	  15VA
	on, active		   4W	  15VA

Page started: 2009-02-13
Last change: 2009-03-11