An Interesting Test with a New Meter

[Unimatic1140]

Posting this in Deluxe as my older LG is part of this test. I purchased a 100AMP electrical usage meter similar to the Kill-A-Watt meter but it is able to withstand much higher amperage than the Kill-A-Watt. I killed two of those meters trying to measure a Unimatic going into spin at 25amps. This new one holds up perfectly and works great. I measured three machines using their most power consuming cycles, my 2007 LG, 1958 Unimatic and 1957 Lady Kenmore. I washed four large 35" x 70" bath sheet towels, which is one the larger loads I do in the vintage machines. The following cycles were used...

2007 LG Sanitary Cycle with Steam selected,
1958 Unimatic with a 10 Minute wash with Hot wash and Warm Rinse,
1957 Lady Kenmore with a 10 Minute wash also Hot/Warm.

I bled the hot water lines to each machine before starting the cycle so the water incoming water was the hottest it could possibly be for all 3 machines.

The results were very interesting. I have the water consumption values from the service manuals of the Kenmore and Frigidaire but I had to estimate what the LG would use. From my research it seems the Sanitary/Steam cycle in the 207 LG uses approximately 12 to 14 gallons total water consumption depending on load size, so I guessed at the lower end of 12 gallons. I also uploaded my gas, water and electric rates right off of my bills into ChatGPT AI for it to read my exact rates and utility taxes and had it perform the calculations to find out how much the electricity and water to run each machine costs as well as the gas costs in heating the water in my water heater.

Here are my results, obviously they should be taken with a grain of salt because I really need two water meters on the line to find out the exact hot and cold water usage of the modern machines. It would be interesting to find out a way to test how much gas the dryer is using to dry the load from each machine. The LG can obviously hold double the capacity of the 1950s machines. Later this year I may replace the LG with a brand new one as my LG is starting to show signs that it is at the end of it's life, which would make for better tests to test a 2025 machine.

In time I would like to get more testing equipment to run further tests, AI has given me some very good ideas in how to test final rinse water to see how well the wash load is rinsed but more equipment is needed.

 

[phillymatt53]

Interesting....
They need to hire you as a tester at Consumer Reports!

 

[henene4]

Getting rinse results could be done with very few extras equipment and some simple assumptions.
But that would be rather a lot of doing.

Also grain of salt - the LG performed a whole different class of cycle.
Heating water - regardless of context - is always the biggest cost in appliances. No matter if it's the hot water supplied to the machine or the machine doing the heating.

 

[mrstickball]

Its always fascinating. I've done this on my channel multiple times with multiple washers.

One big thing thats not entirely factored in the full run of the toploaders is water extraction in the spin process since you opted for the Unimatic on all the processes. That is where a LOT of savings end up happening. Higher RPM spins extract far more water, and older trunion-based systems just cannot compete with a modern frontload machine, or even a topload VMW/Direct drive. Older machines may do 400-600RPm whereas modern frontloads do 1200-1600 depending on drum size and model.

The reason these matter a lot is that it takes approximately 400w to extract 1lb of water from clothing (as far as the math I've seen goes). Modern machines could pull 1-3 more pounds of water in a typical load of clothes, so you will be saving multiple times more electricity on the drying action than the actual wash action of the machines, even.

 

[Unimatic1140]

"One big thing thats not entirely factored in the full run of the toploaders"

Absolutely, MrStickball — I couldn't agree more. Proper water extraction is critical for several reasons. I really should have weighed the towels before and after washing in each machine to compare extraction performance, but by the time I thought of it, they were already soaked. I'll plan to run that test next week when it’s time to wash towels again. Efficiency (both time and utility costs) is one of the main reasons why my Unimatics and early General Electric washers see far more use in my basement than anything else (aside from the fact that they're incredibly fun to use, though that's subjective and outside the scope of this test).

The majority of 20th century American top loaders are certainly more costly to run than the new machines between the amount of hot water used along with way too slow spin speeds.

I would love to figure out a way to calculate how much gas the dryer is using to dry those towels.

P.S. — This test isn’t meant to suggest the LG is somehow less efficient than a Unimatic — it’s clearly more efficient in the long run. What really sparked my curiosity is just how much more efficient it is when measured strictly by utility costs. For most of the year, I only use the LG about once a month for bulky items like comforters that don’t fit in the vintage machines. Otherwise, I don’t use it — there’s no enjoyment in it for me (again, that’s subjective). My boyfriend uses the LG and my customized 910 RPM-spinning Frigidaire 1-18 washer when I’m away for the winter. Everything else gets shut down while I’m gone.

 

[Marky_Mark]

I love tests like this, Robert! You can buy garden hose water meters on Amazon that will enable you to easily measure the exact water usage for each part of the cycle. I have two myself.

As for the gas, you could set a camera to record the dials of your gas meter when the dryer is used (or just sit and watch throughout!). After making sure that no gas will be used elsewhere and also taking a baseline reading to allow for any pilot lights that you don't want to turn off, you can calculate the consumption. My gas meter in Palm Springs has a dial that shows half a cubic foot per revolution and another than shows 2 cubic feet per revolution. So it's easy to see how many cubic feet of natural gas the dryer has used. One cubic foot of natural gas is about 0.293 kWh. So, for example, if the dryer uses 3 kWh of gas to dry a load, the gas meter should show consumption of about 10 cubic feet. From what you wrote above, it looks like you are paying about $0.92 per therm of gas, if I'm correctly interpreting what you wrote. So 1 kWh of gas is $0.03. That's cheap. Does that include any other usage-related add-on costs, such as "gas commodity" charges and taxes etc?

As for testing the rinsing, the UK's Which? has been rating rinsing performance of washing machines for decades but this doesn't seem to be something CR rates. The way that Which? does it is by testing the alkalinity of the water remaining in the laundry after rinsing. I'm not sure how you would measure and allow for the better extraction of a fast-spinning washer compared to a slower one. I would be interested to hear ideas about this. I have tested the alkalinity of the final rinse water, but that doesn't allow for how much water is then left after the spin. Ideas please! I suppose you could then put the spun laundry into a bucket of water or something and measure by how much the alkalinity changes...?

Keep up the good work!
Mark


Edited to strikethrough what I wrote about the cost of your gas, I see now that you quoted it as the price to heat one gallon of water and not the price per therm or cubic foot etc.

 

[mickeyd]

Grain of salt, indeed! You completely cooked the books on this test to favor the '58 Unimatic, while disadvantaging the LG, using its second most LG's most aggressive cycle. Whitest Whites was the obvious choice for this load, in which case LG would have beat the snot out of the other contenders winning with a cost of 25 cents.

Regular Cottons would have been my choice because I have the fill valves rigged to use only Hot water on an LG fill when I want it. If you would order the five dollar part--door latch plug-- to observe the otherworldly drama and the nearly infinite variety of what goes in the LG, you would be as smitten with them as I am, even though I adore my vintages more than ...............hard to say. Launderess always says, "More than her Luggage' :'D

I challenge you to study the machinations of the LG with the commensurate dedication you have devoted to the Unimatic. I was a Doubting Thomas, too, and had to eat five humble pies.

 

[me]

I'm not sure how you would measure and allow for the better extraction of a fast-spinning washer compared to a slower one. I would be interested to hear ideas about this.

You could just weigh a load of 100% cotton towels dry, with an accurate set of digital scales - fishing scales, or luggage scales, then give the same load a rinse and spin in each machine, weighing it again at the end of each spin, and use the difference to the dry weight to calculate the residual water as a percentage of the load.

 

[Unimatic1140]

Hi Mark, I took my entire gas bill (as a pdf) and uploaded it to AI. I asked AI to read entire my bill and then asked AI to calculate how much it costs to heat one gallon of water, including all fees and taxes. It came up with this enormous formula then at the end AI spit out $0.00923 to heat one gallon of water at the stated rates in the bill. I just checked my gas meter and you're right about the dials, mine shows quarter of a foot even. That's an excellent idea to experiment with and this time of year the furnace is shut down until October so there is no pilot light running in it.


Hey Mike long time no see! Grain of salt, indeed! You completely cooked the books on this test to favor the '58 Unimatic, while disadvantaging the LG, using its second most LG's most aggressive cycle. Whitest Whites was the obvious choice for this load, in which case LG would have beat the snot out of the other contenders winning with a cost of 25 cents.

However I used the most aggressive cycle selection on all 3 machines and chose hot/warm on the vintage machines. I also stated in my 2nd post "P.S. — This test isn’t meant to suggest the LG is somehow less efficient than a Unimatic — it’s clearly more efficient in the long run. "

Remember this LG is old, it's from 2007. A better test would be on a 2025 LG as I expect it to be even more efficient than the 2007 model, although that remains to be seen. As you can see from this image from my 2007s' owners manual, this model doesn't have any cycle called "Whitest Whites". I believe the Sanitary/Steam cycle is the most power consuming cycle on this machine. When you select Sanitary/Steam it doesn't allow you to select anything more to the cycle like Extra Rinse or Soil level, all other options except High or Extra High spin go away. As for the door switch and lock, I jumped that out years ago so it could be run with the door open.

If I use the Cotton/Normal cycle and select Hot/Cold on the LG to test, then to be fair I'd have to change the settings on the Kenmore and Unimatic to Hot/Cold as well which will also reduce their costs by quite a bit.

 

[Marky_Mark]

You could just weigh a load of 100% cotton towels dry, with an accurate set of digital scales - fishing scales, or luggage scales, then give the same load a rinse and spin in each machine, weighing it again at the end of each spin, and use the difference to the dry weight to calculate the residual water as a percentage of the load.

Sorry, yes what I wrote was ambiguous. What I meant was that I was not sure how you would measure the rinsing result if you tested the laundry or final rinse water prior to the final spin, as a faster-spinning machine would extract more of the final rinse water and would presumably give a better rinse result. So you really need to know what the rinsing performance is after the final spin. I guess you could just test the final rinse water and then calculate the amount left in the laundry based on the measured spinning performance, which you can easily calculate by doing exactly what you said.

 

[Marky_Mark]

Great thread, Robert! I have never measured the consumption of my gas dryers. Another way to do it would be to look at the flame and time exactly how long in total the gas is burning throughout the cycle and then calculate consumption based on the known burner rating, assuming the burner is not of the modulating type. You've made me want to measure mine now!

 

[maytag85]

Its always fascinating. I've done this on my channel multiple times with multiple washers.

One big thing thats not entirely factored in the full run of the toploaders is water extraction in the spin process since you opted for the Unimatic on all the processes. That is where a LOT of savings end up happening. Higher RPM spins extract far more water, and older trunion-based systems just cannot compete with a modern frontload machine, or even a topload VMW/Direct drive. Older machines may do 400-600RPm whereas modern frontloads do 1200-1600 depending on drum size and model.

The reason these matter a lot is that it takes approximately 400w to extract 1lb of water from clothing (as far as the math I've seen goes). Modern machines could pull 1-3 more pounds of water in a typical load of clothes, so you will be saving multiple times more electricity on the drying action than the actual wash action of the machines, even.

This may sound kind of odd to some, but don’t mind something that spins a little slower. I’ve noticed that items like towels seem to feel softer, same with my clothes as well. My guess is the extra moisture being evaporated makes items a bit more ‘fluffy’ and soft to the touch.

A heat pump my reduce the electricity consumption, but unfortunately the additional complexity will increase maintenance and repair costs, not to mention introducing more areas where things can fail and break down.

 

[Unimatic1140]

This may sound kind of odd to some, but don’t mind something that spins a little slower. I’ve noticed that items like towels seem to feel softer, same with my clothes as well. My guess is the extra moisture being evaporated makes items a bit more ‘fluffy’ and soft to the touch.

That hasn't been my experience Sean, I have found that towels are the least softest when they are:

• Not Rinsed Well,​
• Using too much detergent for the machine type, soil level in the towels and/or load size,​
• Overdried in the dryer or clothes line dried.​

I haven't found spin speed to make any difference in the softness of towels out of the dryer.

Out of sheer curiosity which machines that you are using are producing the softest towels after drying and which machines are producing the scratchiest towels for you?

 

[maytag85]

That hasn't been my experience Sean, I have found that towels are the least softest when they are:

• Not Rinsed Well,​
• Using too much detergent for the machine type, soil level in the towels and/or load size,​
• Overdried in the dryer or clothes line dried.​

I haven't found spin speed to make any difference in the softness of towels out of the dryer.

Out of sheer curiosity which machines that you are using are producing the softest towels after drying and which machines are producing the scratchiest towels for you?

Currently using my ‘63 Whirlpool belt drive which has been outfitted with the late Mark 18 console from 1977.

The matching dryer has the dual wattage element as well which is selected by the ‘speed selector’. The console that came off the dryer that was parted out had a dual tumbling speed feature, since the dual speed tumbling feature can’t be as easily adapted to the older Whirlpool dryers, just mounted a momentary toggle switch which controls the dual wattage element. Technically, the dual speed tumbling feature does work, just tumbles longer since it takes a good while for it to get up to temperature with the 4600 watt heat output.

Maybe it could be something to do with those older Whirlpool dryers, air output and such.

 

[combo52]

Great thread Robert this is something. Of course you know I’ve always been interested in the operating cost of things.

I don’t think the final spin Speed will change the rinsing ability much if there’s detergent or minerals left in the clothing no matter how fast you spin you won’t get all of it out anyway, but it would make a slight difference, of course.

At the warehouse I have acquired an extra gas meter and I’m going to put it in the line going to the vintage dryers and combos so we’ll be able to easily tell if you run one at a time by reading the meter as Mark suggested how much gas a particular dryer uses.

Even though it’s summer, Robert, I believe you still have a pilot burning in your water heater although it wouldn’t make much difference in the result if you’re watching the meter for one dryer load.

And to do a fair cost analysis of running the old lady Kenmore or Frigidaire unimatic you’d have to do it like the typical housewife in Minneapolis did during the time Period and use the wash water at least three times.