How Hot is Hot?

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dalangdon

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Back when we had an electric water heater, I never would have bothered with this question, as they are such pains to adjust the temperature on. But now that we have the tankless, and it is mounted directly above the washer, I was wondering: What is the best hot water temperature for laundry? Right now, we have it set on 122 degrees, but you can easily raise and lower the temperature on this thing. Since all three dogs and the cat sleep with us, I like to make sure the bedding gets sanitized.
 
Most manuals say that 120-degree water is hot. I like to have the water coming in at 140-degrees. By the time the tub and clothes cool it down, it's around 130 during the wash cycle.

If you really want to sanitize, you'll have to use much, much hotter water (over 160-degrees, I believe) or liquid bleach. However, it is my understanding that items dried thoroughly in a dryer are fairly sanitized. Unless you plan to sanitize everything in your house the animals come in contact with, I wouldn't worry much about it. Washing the bed regularly is probably more important than worrying about sanitizing it.

And I think it's sweet that the whole "family" sleeps together, too! You must have a huge bed. My cat and I used to jockey for space on a queen-sized bed, LOL.
 
Paging Peter H!

Dont know about water temperatures, but I am of the opinion that slightly over-drying items sanitizes them effectively. Trick is to make sure one uses the highest termperature setting and ensuring all mositure has gone such that the max. temperature is reached.

A good long cool-down helps prevent wrinkles.

When I really need to sanitize, I go to a commerical laundromat where my understanding is that dryer temps can be as high as 190*F; much hotter than what is normally found in a home-use dryer. (Which IIRC is = or < 140*F).

Excessive water temps can't possibly be good for rubber hoses or plastic washer parts. Perhaps it is time for a Euro boil-washer!
 
i wish you could have seen
the look on my face
the first time i used a miele dryer
in a german waescherei
and examined the elastic waistbands
on my brand new calvin klein extended wear briefs

hey, they didn't tell me to flip the heat dial to maxi
 
Dan, I am able to easily adjust he water temp on my water heater. When I do whites or twoels I simply raise it to 140 or 150 degrees. If your tankless is anything like DADoES, he can temporarily set his up to 140 degrees for about 15 minutes. See if your control panel allows such a temporary setting.
 
Until about the 1980's or so, "Hot" water was 140F-150F, with "Very Hot" 160F to 180F and "Boiling" 200F. However energy and saftey regulations/suggestions have made most modern American hot water heaters put out water around 120F.

Happily modern enzyme detergents work well at 100F to 120F so in theory any TOL detergent should deliver the same cleaning results in "cooler" water temps as hot or boiling. Results are even better with percarbonate or activated perborate bleaching such as Tide with Bleach.

To kill dust mites, one needs 130F or above water temps, and IIRC there are not too many chemicals that will work, well none that you would wish to wash your laundry with anyway.

As for sanitising laundry,hot water was traditionally used not because of disenfecting power, though heat does kill some "germs", but more to the fact that heat was required along with detergent/soap and mechanical action to loosen dirt/grime which is where the bacteria lived (feeding on the stuff). Removing the layer of much from laundry sent the germs down the drain with the wash water alive, but long as they were off your laundry that was all most cared about. Different germs require different temperatures/contact time to be killed via heat, hot water washing is not always the most effective means of "sanitising" laundry by "killing" germs. Again, the most one can hope for is enough of the buggers are deactivated and or sent down the drain to reduce the levels enough so contamination/illness are less of a danger. IIRC Sudsman posted awhile back the differences in bacterial counts of laundry washed at 120F, 140F and 160F are not that great. To really attack germs one would need to add a broad spectrum disenfectant like chlorine bleach, or "boil" the laundry for 15 minutes or longer.

Machine drying along with ironing also help reduce/kill germs, but would be leary of baking one's laundry in commercial laundromat dryers, as it is a sure method of shrinkage.

As for hot water in newer washing machines, it does seem many modern washers with lots of plastic cannot withstand repeated use of water temps above 140F. The new Miele uber washers and some of the other European front loaders top out at 170F or 160F.

L.
 
I set my water heater at 130 degrees, as sort of a compromise for the dishwasher and the laundry and energy efficiency for a 40 gallon older water tank. I use the temp boost on the dishwasher, things come out great and the thing does not run for hours trying to boost itself up to 160. When the operating thermostat on my Maytag dryer went, it was a 140 limit. I went with a 155 operating thermostat limit replacement for REGULAR and kept 135 degrees for PERM PRESS. At 155, I feel pretty sure that micro critters are mostly dead. Operating thermostats on dryers are fairly universal parts made by one or two companies and you can get a higher one for your dryer than the original. Just make sure the high limit thermostat (usually 225 degrees) is working and rated for your dryer to cut off in case the cycling thermostat fails. I like the option of a hotter dryer. A Halo of Heat needs a boost, in my opinion. Built like tanks but slower than molasses in January.
 
For HOT, I run 140°F, which is the maximum my tankless can do. Sometimes I set 130°F. Interestingly, my F&P toploader's ATC targets 115°F for warm (which results in about 105°F actually in the machine when the EcoActive fill is complete). 65°F for controlled cold, 95°F for warm/cold and 125°F for warm/hot (it has six temp selections -- tap cold, cold+, warm/cold, warm, warm/hot, tap hot).

Lukewarm 120°F? I thought it'd be on the cooler side between cold and warm, not between warm and hot.

Note that normal operating temp for my tankless is between 102°F and 105°F -- shower temp.
 
"Sanitize" is a hopelessly vague marketing term. I haven't seen any standard that defines just what it is, have you?

In any case, studies have shown that dust mites are killed at about 118F and above, plus alkaline detergent plus a few minutes of agitation.

But there will still be plenty of dust mites in the carpet, mattress, pillows, etc. Also in your hair.

Studies have also shown that pets do not affect dust mite levels in homes. The mites live on shed human skin.

Fleas are another matter ;-)
 
To kill all bacteria and spores, one must heat an object to 250F in the presence of 15lbs steam pressure, for at least 15 minutes, with the steam allowed to contact all sufaces of the object (permeable cloth or paper wrappings are ok). This is normally referred to as autoclaving, and it can also be done with a stove top pressure cooker.

I remember my mom using a pressure cooker to sterilize a younger sibling's baby bottles.

Dry heat can also sterilize, but if memoery serves me, much higher temps are required - around 350F or more. That's because wet high heat is more lethal to pathogens than dry heat.

And of course nasties like "prions", which are suspected to be the cause of things like Mad Cow disease, are not inactivated by the above methods. To defeat prions one must flame the object. That's because prions are not living things, just wierdly folded proteins that cause other proteins in the body/brain to fold incorrectly as well.

That said, one can never completely sterilize one's living environment without living in some sort of plastic bubble - and that is no way to live.

As was stated earlier, for mast purposes it's more than enough to make sure that all soiling is removed by the laundry process - the germs will be removed along with it. And hot water - 120F or hotter - with a good detergent is the best way to do that.
 
Also with the new water heaters-the 130 degree setting is considered standard-and not a scald hazard.Water temps over 140 degrees were considered a scald hazard by OSHA,and the consumer Product safety comission-sorry to be the "safety Officer"Some bacterias have Mutated to the point where they can withstand even temps above boiling-these live in the Volcanic hot springs-fortunately these bacterias are not dangerous to man.Think these ba cteria live in the water cooling systems of our transmitters-some of them operate by boiling the water to cool the tube.Its sometimes pretty nasty working in the cooling systems.
 
My parents live long lives into thier 80's without this antibacteial germ, bacteria scare bullshit. My grandmother used to just salt the body of the chicken inside and out, when she got it from downtown, live, brought it home on the bus, clucking in a box, and had my grandfather kill it in the back yard, ready to de pluck. I think we are inventing newer, stronger germs by preventing our exposure to them. There is a theory that super santizing leaves us more vulnerable to the next germ/virus that has mutated because we have wiped out it's predecessor and threfore not exosed to its relatives.
 
a joke

"Technically:
Hot = 140
Lukewarm = 120
Warm = 105"

This is absurd. Here in Germany:
Kochwäsche: 95°C = 203°F
Warm: 60°C = 140°F
Lauwarm: 40°C = 104°F
Kalt: 30°C = 86°F

Our washers use 1/4 to 1/3 the amount of energy than the American TLs do for the same amount of laundry...and get our clothes much cleaner. What goes through the EPA idiots' heads? Enzymes and oxygen bleaches need certain temperature ranges to work, and I just do not see enough lactic acid building up at 105°F to really sanitize.

It is true, by the way - the mite problem is caused by us, not the animals. Still, living and sleeping with everything from a hybrid wolf through dogs and many many cats through the years, I feel better washing the bed linens at 60° with enzymes and oxygen bleach. Of course, that "warm" wash lasts for over 75 minutes, not 10. When I am in the US, I use the prewash to make sure the actual wash water is up to 145° (can't get it any higher). Then run the load twice, so it gets 25 minutes wash, not 12. Then rinse twice and spin at 1200rpm. Things come out just as clean as here at home...but that is only because the water is actually at 145° and the drum and clothes are warm enough from the pre-wash to make a decent wash temperature possible.
 
Panthera, you know I love you more than my luggage, however it seems one sit you down for yet another talk about this rather constant and somewhat irritating habit you have of putting down Amercian wash habits. When not putting down American wash habits your tone suggests not so much that those one side of the pond are inferior, but that European washing habits are superior, which is simply not the case.

My mother as well as scores of other Amercian houswives have been doing laundry in automatic washing machines that loaded from the top, with tap hot water (no boiling)and whatever detergents they fancied to get the job done, and guess what? There were no mass outbreaks of disease, no one was shunned not wearing clean clothing or having a whiter than white wash. In a era when children wore hand-me-downs from older siblings, cousins or friends of parents, am here to tell you clothing was retired from service NOT because it was so badly soiled and abused it was no longer useful, but simply because children out grew them.

Laundry involves four factors: time, temp, mechanical action, and chemicals. There are as many ways to achive good laundry results using that formula as there are to say mopping a floor. No way is the best but the way which gives one the results desired.

European laundry machines and habits grew out of the fact 10 or so years were lost due to a horrible war, then it's aftermath. There is also the fact the United States has vast natural resources in terms of oil, coal, natural gas, and such to generate energy to heat water and never in large numbers have worried much about where their clean water comes from and where the dirty water goes. Most Americans today still feel the government has no business mandating how much water their machines should use; if anything governments should do what they do best, affect taxes as a method to cause less consumption of a thing. If one can afford to pay a certian water bill, why should one be forced to purchase a washing machine that treats my laundry like a wet wipe?

Your much talked about "boil" washing has been on the wane in most parts of Europe and the UK for years now. Indeed the average wash temperature on that side of the pond is now about 70C, hence all the detergents designed to work in "cooler" wash temps, including Persil (German and British). Wash times have also become shorter leading to detergents having to adapt as well.

I love my Miele as much as any other Miele owner, but if one had a large household with several children, you can bet would have a vintage Maytag, Kenmore, Frigidiare or any other built like a tank front loader to speed though my wash day. I may be a vintage laundry appliance buff, but there are times when one does not fancy spending hours doing several loads of laundry. And please don't give me that palaver about doing one or two loads of wash each day a la European style. Amercian housewives embraced large top loading washing machines, and later dryers because they could do a weeks worth of laundry quickly and efficently. Doing laundry over a period of days was something their grandmothers/great-grandmothers did and they saw the physical toll it took on them. Not to mention on the women themselves as they were likely dragooned into service on wash days at the cost of missing school or other things.

L.
 
Dear Laundress, our voice of reason. Agree wholeheartedly with your comments. Another factor to consider is that as more women were in the work force than ever before, those large capacity American TL's were necessary or else in addition to working all week, raising family, shopping, preparing meals and general housework, she would have been doing laundry endlessly with a small Euro front loader. Whether our ridiculously fast paced lives here in the US are right or wrong (and I have my own issues with that), the Euro approach to laundry isn't the most practical.
 
Well,

Laundress,
I do apologize for being so hyper-critical.
I left the US at a time when human rights and American grown technology were important.
Have lived in Europe the last 25 years - where these two aspects of life have continued to be important.
Am returning to a country which has lost its technical edge and which no longer even recognizes habeas corpus.
So the culture shock and my anxieties come out in very negative comments.
It is hard for me to compare an A108 or a real thumper to what is on the market today and believe that it cleans.
Sorry. I'll keep trying to lighten up.
 
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