brian@ut-sally.UUCP (Brian Powell) (01/31/85)
When I visited the World's Fair this past summer, I saw a home hot water
heater device that was kind of interesting.
It was a small device; you could hold it in your hands. But it was
supposed to work just as well as the reservoir-type heaters we are accustomed
to. I think it worked on the same principle as those traveler's single-cup
water heaters. (A heating element you put in the water.)
The people at the Fair said that they have used this kind of hot water
heater in Europe for years. They also said this kind is better for 3 reasons:
1) More efficient. It only heats when the water is running through it. You
don't have to keep 50 gallons warm all the time.
2) You don't run out of hot water. Apparently, It can heat it up fast
enough.
3) Oh yes, it is also cheaper.
Has anybody had any experience with these things?
Brian H. Powell brian@ut-sallymag@whuxlm.UUCP (Gray Michael A) (02/02/85)
> > When I visited the World's Fair this past summer, I saw a home hot water > heater device that was kind of interesting. > > It was a small device; you could hold it in your hands. But it was > supposed to work just as well as the reservoir-type heaters we are accustomed > to. I think it worked on the same principle as those traveler's single-cup > water heaters. (A heating element you put in the water.) > > The people at the Fair said that they have used this kind of hot water > heater in Europe for years. They also said this kind is better for 3 reasons: > 1) More efficient. It only heats when the water is running through it. You > don't have to keep 50 gallons warm all the time. > 2) You don't run out of hot water. Apparently, It can heat it up fast > enough. > 3) Oh yes, it is also cheaper. > > Has anybody had any experience with these things? > > Brian H. Powell brian@ut-sally A friend of mine is an architect and she has experience with these things. They work fine. They take little space. However, they need large electric supplies (like 50 amps minimum), so heavy duty wiring is necessary. If you assume 50 amps at 117 volts, you have 6850 watts, or 6.85 kwh/hr, meaning that, at 11 cents per kwh, you are paying about 75 cents an hour to operate a small one. Her cost analyses have indicated that they are excellent for say, a church or a weekend home, where keeping 100 gallons of water hot during long periods of no demand would be expensive. She does not recommend them for other installations, since natural gas costs so much less. Incidentally, I spent a few years in Europe and another common method used the same idea of heating only on demand, but it used gas! There was a large (2 feet by 3 feet by 1 foot) nest of water pipes above the tub. When you turned on the water, a giant gas flame came on (with a WHOOSH!) and heated the pipes. Worked well, but the water was excruciatingly hot, so care was necessary. Mike Gray, BTL, WH
hollombe@ttidcc.UUCP (Jerry Hollombe) (02/02/85)
>From: brian@ut-sally.UUCP (Brian Powell) >Subject: Info on hot water heater gizmo? >Message-ID: <775@ut-sally.UUCP> When I lived in London, I frequently had to deal with these things. The British call them geysers (pronounced geezers). There's a lot of variation in quality among them and the convenience is dubious. Because of the design, the temperature of the water varies with the pressure and quantity of water going through the device. In the smaller units, just a slight adjustment of the flow makes the difference between scalding and luke-warm. It also takes a while to get a lot of hot water from them. The larger units can actually generate live steam through your sink faucet. The smaller ones typically aren't routed through a faucet. They just hang on the wall with an "S" shaped pipe leading to the sink. (Not very aesthetic.) Modern energy-saving tank water heaters are probably not much less efficient if you use a lot of hot water (a lot = daily bathing and washing up of an average family). They are vastly more convenient in most cases. I think that, unless you live alone and only bathe weekly (which tends to insure living alone (-: ), you're better off getting a water-heater blanket and insulating your pipes if you're interested in efficiency. The geysers are a lot more trouble than they're worth. -- ============================================================================== The Polymath (Jerry Hollombe) Citicorp TTI If thy CRT offend thee, pluck 3100 Ocean Park Blvd. it out and cast it from thee. Santa Monica, California 90405 (213) 450-9111, ext. 2483 {vortex,philabs}!ttidca!ttidcc!hollombe
wmartin@brl-tgr.ARPA (Will Martin ) (02/05/85)
> Incidentally, I spent a few years in Europe and another common method > used the same idea of heating only on demand, but it used gas! There was > a large (2 feet by 3 feet by 1 foot) nest of water pipes above the tub. > When you turned on the water, a giant gas flame came on (with a WHOOSH!) > and heated the pipes. Worked well, but the water was excruciatingly > hot, so care was necessary. > > Mike Gray, BTL, WH For what it's worth, this is not a newfangled invention, brought on by the energy crisis. This was the standard type of water heater from 75 or so years ago. My grandparent's house (which I subsequently owned for a while) had these, and they were replaced with tank-type (ordinary) water heaters during the 50's. The key here is the amount of water used for showers and automatic washing machines. If you don't have a shower (this house, and many older unremodeled houses, didn't), you can run your bath with water that is too hot at first but that cools off, and end with an average temperature tub of water that is fine for a bath. When you have a shower, you have to keep a constant temperature, neither scalding nor cold. The in-line water heater units don't do well on this. Same for washing machines. It doesn't matter too much if you use a wringer washer and laundry tubs; you adjust the temperature the same as a bath. However, earlier automatic washers (which did not use cold water only for rinsing, and couldn't, due to the detergents of the time) needed a more constant flow of even-tempered water. Flash or in-line heaters are often used as backups in solar hot-water installations (an example of this was in the first of this season's "This Old House" PBS TV series renovations, if you saw that); you have a reserve tank of solar-heated water and the in-line heater takes care of the times you run out or for exceptionally cloudy periods. The tank acts as a buffer. Just having flash or in-line water heaters is feasible in certain special circumstances, or in limited usage. But the tank-type heater has advantages for most normal households. There is nothing new under the sun... Regards, Will Martin USENET: seismo!brl-bmd!wmartin or ARPA/MILNET: wmartin@almsa-1.ARPA
mike@amdcad.UUCP (Mike Parker) (02/05/85)
In response to Brian Powell's query about "tankless" hot water heaters. I have limited experience with them, and it's very contradictory but I'll throw it out and see if I can at least catch a few flames. I tried to buy one once and found that their power output tended to be quite low. This governs the product of flow rate and temperature differential across the unit. My conclusion was that a good hot pounding shower would not possible and I ditched the idea. Since then I've stayed in two homes with these heaters. In one my analysis proved correct the shower provided a hot trickle or a lukewarm shower. If I had owned that house I would have immediately taken an axe to that damn thing and gotten a real water heater. In the other place the problem was the opposite. The heater was gas powered and was in a closet behind the tub. When I turned on the hot water and heard the flame start, I thought someone was warming up an F14 in the driveway. The thing put out an incredible flow rate of steaming water. Unfortunately the people who owned the house had installed some antique brass fixtures. When hot water flowed through the faucet the valve stem would expand and the flow would reduce. The heater had only one power setting *ON* we're talking F14 ON. So the temperature differential across the heater was directly proportional to the flow rate. The heater in combination with the brass fixtures was bistable. If you set the thing for hot, the fixture slowed the flow causing the output temperature of the heater to go up and the fixture to further slow the flow. Ultimately all hot water flow stopped and there you stood in a cold shower. The were other temperature settings that caused the fixture to gradually increase the flow thus lowering the heater output temp and further increasing the flow, I was almost seriously burned when I discovered this phenomenon. In summary: If you are thinking of getting one of these heaters make sure it is of the F14 variety and get quality fixtures that are not sensitive to water temperature. Mike @ AMDCAD
capener@hplabs.UUCP (Chris Capener) (02/06/85)
> > When I visited the World's Fair this past summer, I saw a home hot water > heater device that was kind of interesting. > > It was a small device; you could hold it in your hands. But it was > supposed to work just as well as the reservoir-type heaters we are accustomed > to. I think it worked on the same principle as those traveler's single-cup > water heaters. (A heating element you put in the water.) > > The people at the Fair said that they have used this kind of hot water > heater in Europe for years. They also said this kind is better for 3 reasons: > 1) More efficient. It only heats when the water is running through it. You > don't have to keep 50 gallons warm all the time. > 2) You don't run out of hot water. Apparently, It can heat it up fast > enough. > 3) Oh yes, it is also cheaper. > > Has anybody had any experience with these things? > > Brian H. Powell brian@ut-sally I lived in France for a couple of years and had daily experience with those things. The water comes out cold at first for a few seconds and then does warm up. But if you turn off the water for less than a couple of minutes and then turn it back on it comes out SCALDING hot. Makes taking showers very interesting. The problem is that the chamber contiues to transfer heat to the now stationary water for while. I prefer the standard resrvoir type.
ron@brl-tgr.ARPA (Ron Natalie <ron>) (02/06/85)
> If you set the thing for hot, the fixture slowed the flow > causing the output temperature of the heater to go up and > the fixture to further slow the flow. Ultimately all hot water flow > stopped and there you stood in a cold shower. The were other > temperature settings that caused the fixture to gradually > increase the flow thus lowering the heater output temp and > further increasing the flow, I was almost seriously burned > when I discovered this phenomenon. > > In summary: > > If you are thinking of getting one of these heaters make > sure it is of the F14 variety and get quality fixtures that > are not sensitive to water temperature. > Of course one solution is to get temperature controlled fixtures. In Europe (the only place I've actually seen one in a bathroom, although I've seen them in the US in darkroom sinks), I've seen calibrated knobs in the bathroom for hot water temperature, and then your shower control was just a flow control. -Ron
jerry@oliveb.UUCP (Jerry Aguirre) (02/12/85)
I can only state what I have read. They are supposed to be working on
regulated versions of the tank-less water heaters. Current versions do
give a small amount of hot water or a large amount of luke-warm water.
There is a solution for showers though. It is an shower control that
automaticaly adjusts the temperature. Some codes require this type of
shower valve on all new installations. The idea is to prevent the
person in the shower getting scalded when someone else flushes the toilet.
The valve has a bimetal control built into it that will regulate the mix
of hot and cold water to keep the same temperature. Should work for a
tank-less heater.
Jerry Aguirre @ Olivetti ATC
{hplabs|fortune|idi|ihnp4|tolerant|allegra|tymix}!oliveb!jerrymike@amdcad.UUCP (Mike Parker) (02/13/85)
> > There is a solution for showers though. It is an shower control that > automaticaly adjusts the temperature. Some codes require this type of > shower valve on all new installations. The idea is to prevent the > person in the shower getting scalded when someone else flushes the toilet. > The valve has a bimetal control built into it that will regulate the mix > of hot and cold water to keep the same temperature. Should work for a > tank-less heater. > > Jerry Aguirre @ Olivetti ATC > {hplabs|fortune|idi|ihnp4|tolerant|allegra|tymix}!oliveb!jerry Be careful buying these. There such controls available that have a bimetal control to take into account variationa in the water temp. However, the vast majority of constant temperature shower controls rely on the fact that "flushing the toilet" lowers the pressure in the cold water pipes more than in the hot. They rely on little spring loaded gizmos to adjust. This will not solve the positive feedback problem of tankless water heaters. I do not know if there is a sure fire way to tell if you are getting bimetal or springs in one of these units, anybody on the net try to buy one lately? Mike @ AMDCAD
joel@prcrs.UUCP (Joel C. McClung) (02/15/85)
I seem to remember reading about some Navy seaman getting some award
from the Navy for coming up with a simple yet effective solution
to being scalded in the shower whenever someone flushes the toilet.
He put a coffee can in the water line right before the shower head.
Anytime someone flushed the toilet, the water would get hot, but
would be diluted in the one-gallon can and the person taking the
shower would never feel it.
--
Joel C. McClung
Planning Research Corporation
(703) 556-2644
seismo! \
allegra! > rlgvax! \
ihnp4! / > prcrs!joel
nrcaero! /
petsd! /