My washer and dryer energy usage measurements
 

I decided today to start tracking the energy usage of my washer and dryer since I do a lot of laundry due to a family of 4 with 2 kids under 3.

The first thing I did was slap together a spreadsheet to record
Then I calculate kwh used, kwh saved, $ spent, $ saved on each line

the initial part is just the number of each type of loads done each day.

The calculations are simple.
I've previously estimated the dryer to use 2.257 kwh per load based on it's energuide rating.

I'm currently measuring the cold water wash usage with my wattmeter.

I'll need to do an estimate for the hotwater usage since I'm not able to directly measure the energy used to heat the water.

a parital/tumble dryer load is 1/3 of a complete load for my purposes.

kwh saved is dryer loads put to the clothes line or 2/3 in the case of partial/tumble dryed loads.

Nothing shocking or difficult I know but the first thing I noticed when setting up the watt meter is my one year old GE front load washer uses 4 watt when turned off which in my mind is stupid since it's not maintaining a program setting or a clock or doing anything. when it's turned on but idle it uses the same amount. So much for my running over to hit power when the load is done to save that little bit.

I'll update with values when the watt meter finishes collecting. <edit> Averaging .15 kwh for a cold water wash after a few loads ranging consisting of clothes, towels and bedding

I found that the average load take 13.73 gallons of water so to heat it from my base temp to 110 takes 2.4 kwh which I've now added to my hot water loads energy costs.

</edit>

I'm glad you're tracking this. I just started tracking mine too. I have a top loading Whirlpool washer that is probably 5-10 years old. So far I've found that a medium sized cold water load set to regular plus an extra rinse uses .32 kwh. A super sized cold water load set to regular is .24 kwh adding an extra rinse cycle bumps that to .34 kwh. I won't pollute your thread any more, but I thought the comparison was interesting. I'll start my own thread after I've recorded more loads.

Weekly update Oct 18 - 25th

It's definitely fall here with lots of rain so the clothes line didn't get much use and the indoor one is in the middle of a construction zone at the moment.

We did 7 loads of laundry, 100% washed in cold 6 dried in the dryer 1 on the clothes line and 2 partial dryer loads ( one of quilts wasn't quite dry and the clothes line was a bit damp)

Usage was

16.08 kwh, costing $1.24 saved was 2.257 kwh or $0.174

This is a pretty typical weeks worth of loads for me in my mind, we'll see if the numbers stay consistent. During summer I'd dry 3/4 or more of those loads outside. Not counting any possible hotwater costs we're near $65/year to do our laundry.

I decided that my savings calculation was wrong. I no longer account 2/3 of a dryer load to savings when doing a partial dry. I instead just count it as 1/3 the cost.

<edit> correcting my numbers </edit>

I've decided to do a monthly update of my usage. If anyone actually cares for more detail just ask away, I track daily here.

The weather is ugly fall/winter so clothes line usage is way down for me.

From october 17th to November 17th

31 Cold loads washed
4 Hot loads washed
29 Loads dried in dryer
3 loads dried on clothes lines
5 loads partially dried in drier
94.57 KWH costing $7.28 estimated to have been used
6.77 KWH worth $0.52 estimated to have been saved using the clothes line
69.84 KWH worth $5.38 estimated to have been saved using cold water

for a grand total savings of $5.90 by using cold and the clothes line.


3.24 lbs of C02 generated and 2.4 lbs were saved

it seems like a lot of laundry and it is but I believe it's less then the "average" the energystar people use.

I think I should stay here more. i like the threads..

My electric bill just arrived. My estimate is the laundry accounts for 13% of it. Which in the grand scheme of things is really pretty good. Doing all this laundry without electricity would take way more then 13% of my time.

It's been forever since I've updated this. It's been 282 days since I started recording this data. During this time I've done

216 cold water loads
35 hot water loads

193 loads went in the dryer
38 went on the clothes line
13 needed partial dryer runs to finish what the clothes line started.

So the dryer is obviously heavily used and looking at the numbers it uses more power then the cold water saves. Still by my calculations the cold water has saved me 378.5 kwh and the clothes line has saved me 85.8 kwh which in total has saved me $35.75

I started recording in mid/late Fall and we had a brutal spring so the clothes line usage being so low isn't unexpected. It has been used 22 times in the last two months accounting for 52% of the loads. summer only really got here this last week so hopefully I'll get that close to 90% for the next month or so.

All of this laundry has cost me $42.09 in electricity using 546.58 kwh so I haven't quite saved 50% yet. Still I find the effort of using the clothes line minor in the grand scheme of things and I quite enjoy the process of hanging it.

I've also used an estimated 7321 gallons of water. That is taken from some where that averaged what my machine uses per load. The actual number could be quite different.

Great info. How are you keeping track of / gathering this info?

manually counting the loads and where it ends up. the rest is calculated based on those numbers, the kwh meter readings I did months ago and the energy star numbers

Yeah, I can see you haven't done it enough times yet;)

I dunno how it is in North America, but European washing machines have a spin cycle at the end which can be as fast as 1200rpm (which can be reduced to 1000, 800, 600, 400, or 0 rpm depending on how delicate the load is). This squeezes most of the water out, reducing the need for drying. Our machine only does 800rpm and sometimes giving the laundry a second spin makes it only damp, not wet, when finished. A faster spin would use a little more power, but would make the laundry even less wet. Not an issue when we dry outdoors, but helps in spring/autumn when it's cold and damp, indoors and out.