How cold is "too cold" water?

[dj-gabriele]

And I am an Energy Engineer...

And I add you don't know what you're talking about as you're mixing energy units and power units! What saddens me the most is the presumption behind the affirmation "And P.S. I do hold a degree in Physics!": you're utterly ignorant and it shows big time. I would have kept my mouth shout and answered you in private but this is no longer the case.

Cit. "saying "kWh (or 3,6MJ) is the same as saying "65kph is 65kilometers". That means nothing! Direct from Physics like I stated>>>> 1 WATT = JOULE /SECOND look it up and learn!"

What has that have to do with the discussion!?

1 [Watt] IS 1 [J/s] measure of power (so very true, nobody is saying that this is wrong!)

But the thing that you're not understanding is that one kilowatt hour is a measure of energy and one kilowatt hour is exactly three millions 6 hundred thousand Joules (as I wrote). If you can't understand this very basic concept we can't discuss! Or maybe you should re-learn what you studied when you got your degree otherwise you will keep staying in you state of total ignorance.

Or want me to use only units you're familiar about? I can convert all of what I said in Joules or calories or TEP or whatever. I know what I'm talking about!

AND PLEASE: cite the text where I said that "Jetcone is stupid" as I didn't ever write such a thing.

PS: I'm sharing this link on wikipedia so you can learn what a kWh is, it explains everything clearly, after that, when both of us know what we're talking about we can discuss.

PPS: for the other guys I'm very sorry for having hijacked the discussion but I can't stand this kind of crass errors imposed ad the truth revealed!

Loading…

en.wikipedia.org

 

[jetcone]

Gabriele

Lets drop the hatchet, I will concede you didn't' call me stupid directly.

But from your wikipedia link here is the direct quote:

"The kilowatt-hour (symbolized kWh) is a unit of energy equivalent to one kilowatt (1 kW) of power expended for one hour (1 h) of time.
Inversely, one watt is equal to 1 J/s."
QED.

I was talking about amount of energy expended by the dryer. I think you are talking about a billing rate or what it costs. Two different things. Lets agree to disagree.

Jon

 

[tomturbomatic]

I still think it is important to this discussion to note that Jon uses condensing combination washer dryers and heating the whole system, machine parts as well as laundry, with gas heated warm rinse water (or with a final hot rinse in the case of the GE combo when set for a hot wash) is faster and cheaper than heating it with the electric heating element when the machine starts drying. The only part of the combo that you want to be cold for the drying operation is the condensation chamber. Any other benefits such as probably better rinsing and water extraction from the warm rinses are for lagniappe.

 

[philr]

I'm among those who usually use warm rinse. I just think that cold tap water is too cold to use for laundry where I live (and I rarely use the permanent press cycle)... Of course, I'm aware that my (electric) water heater has to reheat the 40°F cold water to 140°F and it might cost a bit more than just letting the hot water sit in the tank and be just maintained to it's temperature but I don't care much about that! That's why I have a water heater!

A real waste of money would be not using this already heated water when needed!  So to wash (and rinse!) myself, the dishes (with or without the dishwasher which also fills with hot water, even for rinses!), also my clothes and I even feed my plants with warm water! I even use hot/warm water to wash my cars, but I do rinse them with cold water from the garden hose just because I don't have hot water outside!

Otherwise, I just could get rid of the water heater! That's why one of my neighbors got rid of his hot water tank, but he also got rid of the broil element in his electric oven because he didn't like when it turned on for a faster pre-heat... He also disconnected his frost free refrigerator for the same reason an he now washes himself with water he heats on his wood stove! He doesn't pay for wood so if it's ok for him, well... And I know he does have an old WCI Frigidaire washer that looks like new and it probably is as it's not even connected. Too bad his washer isn't just a few years older! And I didn't ask him how he washes his clothes! He does like to spend his money on other things, like cigarettes and alcohol! That's his choices, I respect them but I wouldn't like living like he does!

 

 

 

[yogitunes]

lets have a little fun with this, if we can......

for the people who have access to the ideas or concept.....how would you go about making a solar powered hot water heater.....nothing lavish, more on the practical side with stuff you already have......

just a simple idea I did once, but the garden hose that lays outside, in direct sunlight, really heats the water inside, although I have never measured the exact temp.....and hooked it up to 2 of my Neptunes, granted I only needed a few gallons per fill, but I was getting somewhat hot washes and warm rinses, with no energy at all.......

I just wonder if we could take this a step further, either a rack of plastic pipe assembled and placed on the roof of the house, or a length of garden hose just laying out in the back yard, and piped to the washers........how much pipe or hose would be needed to equal a 30/40 gal hot water tank?.....

just curious if this would work on a bigger level for a TL washer.....and wondering how long would it take to replenish...even if it only gave warm wash and rinses.....and of course really only works in the Summer at best....

I know some of you guys have machines in the garage or sheds with no hot water tank...but what if something as simple as 200/300 ft of garden hose on the roof gave you heated water at no cost other than a few supplies, which for the most part you already have....just a thought

I would like your ideas or thoughts on this....

 

[philr]

Martin,

Another neighbor has a black hose or Carlon pipe on the roof of his garage during summer. I think he uses it to heat water for his swimming pool.

 

The problem with solar power is that's it's missing on cold or cloudy days and after the sun sets! And if you live in area where the water freezes, you also need to flush (and even uninstall) this system for the cold season. Might work during summer time to preheat water to the water heater (maybe through black Carlon aerial pipes) but it would be useful only when the weather is nice and the sun is present.

 

Or it could be used for a fun washing experiment outside on a sunny day with a closed circuit. Using a sump pump in a plastic drum to circulate water through a black hose sitting under the sun, Then to reuse wash/rinse water, and to refill non suds-saver machines! But it might be a bit tricky to refill some metered filled solid tubs with this arrangement...

 

[jetcone]

Martin

in the 70's around Boston we saw a lot of homes install roof heaters that were made similar to what you are suggesting using hard pipe with water inside that circulated. Some circulated with gravity/convection some had pumps on the lines. In fact there is still one operating not 2 blocks from me.

But over time I heard there were problems with these systems so they slowly faded away and a lot of these people replaced them with photo-voltaic cells on the roof.

One person told me the pipes or pumps would clog with something regularly and you had to get up on the roof to fix it( NO THANK YOU), another told me you had to keep maintaining the black paint on the pipes other wise the sun bleaching of it caused a big drop in efficiency.( Again up on the roof to fix)
I have heard from a few of these people that they like the PVCells better they think it makes more hot water.
But thats all anecdotal so I'm not sure.
But was is surprising is all these early adapters were the first to go with the next generation of solar which was PVCells, I think they already had the mounting hardware on the roof from the piping systems so it was easier to do.

When we were driving across Canada with our RV we had this outdoor portable shower that you filled and left in the sun, and man the water got HOT!! You had to mix it with cool water to shower. There wasn't gobs of it but there was enough and it was HOT!

 

[yogitunes]

DIY..........

heres a video of a guy in Texas who built a home made solar water heating grid.....

seems simple enough, even for the top of a garage or laundry shed.....free hot water at temps up to 160 degrees.....that will get your whites white!....how much could this really cost versus the savings....even if just for the washing machines!....

 

[DirectDriveDave]

Safe Water Temperature

What is the usual safest hot water temperature, not for your hands but for the machines themselves, sometimes I feel that water that is too hot could damage something on the machine.

(our hot water is 120F)

 

[launderess]

Can't Be Sure

But IIRC Miele's hot water intake hose is labeled not to exceed 140F.

 

[yogitunes]

my current gas powered water heater is set at 150 degrees.......but some machines do have cautions about too high......

I wouldn't mind having this solar set up piped to the dishwasher as well....especially at this temp....

but if it was to get that hot or higher, a tempering valve could be installed...wouldn't that be funny, free hot water that you have to temper down...or even a pressure relief valve installed in the "rack" for overtemps..

but just the same, the garden hose heats water sometimes that for the first few minutes, the nozzle gets too hot to hold....

 

[tomturbomatic]

Iceland has long had to temper the geothermal hot water with cold to make it safe for household use.