Hot water for shoer

[micky]

They have an insteresting system here in Guatemala at the cheap and maybe not so cheap hotels. It never gets very cold here and piped hot water is for many a luxury (although my cheap $1/night hotel had hot water in the shared shower in 1971. That we shared it did't save them any money on hot water, but I digress.

Now what I've seen in I think 4 hotels out of 8 (maybe more since I only remember 2 that didn't use this) is an elextric heater right at the shower head. It's about the shape of a stick of butter, but 150% as wide and as high. The same length.

The wires are showing and sometimes just taped up, but of course they are above the pipe so they don't get wet.

It works almost immediately. I don't have to turn on anything but the water (one handle) and it can actually make the water hotter than I like. Tonight it was that way so I opened the faucet more and the cooled it off a little (since it only has one heat setting, I think. )

I can think of a lot of places in the US this could be used.

[Jim Joyce]

During the period 1980-1991, I lived in about a dozen places in Germany and most, if not all, of them had what you described. They were located in the bath/shower, the bathroom sink(s), and the kitchen sink. They automatically turned on when they sensed the flow of water and turned off immediately as the flow stopped.

[Clare Snyder]

They call those abominations "widowmakers" for good reason.

[Clare Snyder]

Point of use heaters are fine - they are generally out of reach and in the dry. Showerhead water heaters are a different story. particularly dangerous when 240 volts. If you are going to use something like that at the very least put it on a GFCI. (and you will find the GFCI trips quite regularly!!)

[Ed P]

There has been a push for the instant water heaters in recent years. They can save a lot of money in some situations. A couple of times a year I stay with my friends and she has one in her vacation home. I don't like it, but it makes sense not to keep 40 gallons of water hot when not occupied for long periods. Problem is, with low flow it shuts off so if you just want a trickle, no good.

[danny burstein]

[snip]

It's called a "instant point of use" water heater. In the US they're available but are NOT at the shower head 'cuz safety, but can be located in a small cabinet next to the sink/shower.

The problem is... how fast and how much water they can handle.

For example, a 12 amp heater at 120V -> 1,440 watts [a], which (using US terminology) -> 4,913 BTU/HR. Let's round it off to 5,000 to make life easy

[a] basic wiring is 15 amps, but you're supposed to "derate" coninuous loads to 80%. Which will be usually but certainly not always followed in the US

Now figure on incoming water temperature of 55 degrees F (warmer in Phoenix, of course..) and you want it to be 105 degrees, that's a 50 degree increase.

So... 5,000 BTU divided by 50 degrees -> 100 pounds of water/hr, or.. 1.5 pounds/minute. As water weights about 8 pounds/gallon, that's about 0.2 (rounded) gallons/minute (1/5th of a gallon, or about 25 ounces of water/minute).

Now... if you put in a 240V system, and raise it to a full 20 amp circuit, you can go up to..

240 times 16 -> 3,840 watts -> 13,100, or about 2.5 times the basic US number -> about 1/2 gallon/minute.

Since most of the world outside the US uses 240V as the basic wiring, and... they won't derate the ampacity, then yeah, you can probably pull a gallon/minute. Add in some more because the incoming water is likely warmer.

Anyway... getting back to the US: an "Instant" pont of use water heater for a shower requires significant rewiring. Not unheard of, but rare.

However, having one for the sink kind of works. And especially if you have a small, say 5 gallon, water heater tank there.

[Clare Snyder]

We just installed a 12 gallon (canadian) water heater under the counter in the kitchen of the church.. The main heater is quite a distance away - like 8 gallons worth of pipe. The small heater is set marginally cooler than the big one so when the hot water from the big heater hits the little one it (the little one) shuts off.

[micky]

There is a breaker box in this bathroom (though I don't remember one in the others) but it's too high for me to reach or even read.

[micky]

Well I'm not even married so I'll get the last laugh.

[micky]

To be clear, I know about those. I even considered one for my bathroom because I'm tired of waiting for hot water from the basement. But they require crawling into the sink cabinet, cutting into pipes, but here all that would be needed is taking off the shower head. (I did that when I moved into my house but (don't tell anyone) I did it to replace the regular shower head with a high volume one.)

This installs easily by just replacing the shower head and if you lose a few innocent people, remember that to make an omelette, you have to break some eggs.

Your explanation now continues with no interruption.

[Dean]

I replaced my tank water heater with a Rinnai tankless one. My dishwasher and shower are the only things that infrequently use hot water. I've washed clothes in cold water for as long as I can remember. They came out clean enough for work clothes. They mostly had mud and sweat on them in the summer. They were cleaner in the winter when I was wearing coveralls to keep warm. I just couldn't see the sense in keeping a tank of water hot all the time for my situation. It might be different for a large family but a little planning for hot water use could eliminate the need for a big tank of hot water sitting there constantly.

[Ralph Mowery]

They tried that where I worked but foung out that it would take a lt of time and effort to run the wiring for the current it would require. They had the heater installed but took it out and installed a small water herter tank.

[invalid unparseable]

With our recent 2 day power outage I was able to take a hot shower the second day. My portable generator does not cover the electric hot water tank but water stayed hot.

[Ed P]

I use gas for hot water, cooking, grilling, drying clothes, dishwashing. My gas bill runs $9 a month. That also keeps 40 gallons hot and ready.

At my friend's place: The problem I have with the tankless is flow. A couple of times in the shower at a modest temperature mix, the tankless would stop heating and I'd have to crank it up to get it started.

Same with low flow in the sink when shaving.

Not my house where I use it so I'm not tinkering but for my situation, not for me. This is a summer home, often unoccupied for weeks so makes some sense there.

[trader_4]

Just replacing the shower head and then what? It needs to be powered, so now I suppose you're just supposed to rig it up with an extension cord to wherever a receptacle is available and duct tape it in place. No safety or code issues there of course. And then in the US it's going to be 120V, which is going to have half the heating capacity of 240V, which is probably what they have in Guatemala. With typical water temperature in the US, that's going to still be a cold shower. I bet they don't have GFCI there either. BTW, what are you doing down there? Rounding up another train load of immigrants with Democrat promises of easy illegal entry, free housing and meals in NYC? Somebody has to be doing it.

[Ralph Mowery]

Not to quibble over numbers but it is 1/4 the power when the voltage is cut in half. Any way it will require wiring a high current line no matter what the voltage is to the shower to heat enought water, especially in the winter when the water may be much colder than in the summer.

Point of use heaters are a wishful good idea for older homes. It usually requires a major rewiring upgrade for the instant water heaters. . I am beginning to think the illegals are a good idea. Someone has to do the lithiun mining for all the batteries for the greenies.

[Scott Lurndal]

Not to quibble, but your math doesn't work.

Power = Volts * Amperes

$ v=120 $ a=20 $ printf "%u\n" $(( v * a ))

2400 $ printf "%u\n" $(( (v/2) * a )) 1200

[trader_4]

His math is assuming that the same resistance heating element is used when going from 240V to 120V. That results in 1/4 power. Yours is assuming that you change it to one that is half the resistance, to get the max power drawing the same amps, that gives 1/2 power.

[Ralph Mowery]

I was thinking of the heating element that would draw 1/2 the current . Anyway it is still going to take a lot of power to get hot water for a shower unless the flow is cut to a trickle.

Point of use may be ok in a new house if wired for it, I don't know but I will still go with a tank. While our power is seldom out very long, if it does go out for a while and I want hot water I can get hot water for a short time and if I cut off almost everything in the house I can heat up the water in the tank with my 5 kw generator. A point of use may give you a hot shower, I would have to look that up, but for now it is not worth the trouble for me to check into it. The electric bill is about the lowest bill I have other than the Ment Mobile cell phone Trader put me on to. I think I saw where it may be going up if Duke enegery gets it passed.

[micky]

Hey, you're right!

I don't think you're supposed to do that, and none of the hotels I've stayed at did that.

No, Guatemala is 120v.

The receptacles are the same as the US. I am pretty sure every hotel I've stayed in, no matter how cheap, has had 3-prong receptacles. This one does.

It's true that it doesn't get below 50 here, except rarely. The woman who gave me a tour of the Aurora coffee plantation (paid, but not much**) said that this year was too cold, too hot, and too wet (rain) and it had hurt the coffee crop.

**January is the Monday of the year. And monday is the day all the museums etc. are closed, meaning January is the month t he least tourists visit, so I was the only one on the tour, which cost about $7 and lasted about an hour, but in other months, there could be 20 or more on the same tour. Strange that it's quiet here in Enero when that's maybe the coldest month in the US. Here the temps are about the same year round iirc, but it normally rains in the summer and not the winter. Indeed, rain was predicted for 3 or 4 days last week but I didn't see any, except an earlier day when I don't know what the prediction was.

I"m sure they do, but I don't know what was used in each hotel, or in any of the hotels.

Yes. I didn't want to admit this when I was in "Maryland", but I make my money by doing just that. I charter buses and go to the border with El Salvador. Then the drivers take the buses to Mexico. They usually drop me off whe they pass by Guatemala City, or alternatively, sometimes I get on there. I'm learning Venezuelan and Columbian patois. My counterparts handle it in Mexico, El Salvador, Honduras, Nicaraugua, Costa Rica, and Panama. The 7 of us are in a special arrangement, and we vacation together at one of the famous resort islands not far off shore. (I can't say which one. Security isssue. )

So this whole trip goes on my expense account, funded by a semi-well known Democratic donor. If I can carry more this year than my predecessor did, I get a big bonus. And I mean big. It's a 5-month all expense paid mostly guided tour of Africa. I hope I win it.