Turn your geyser off for 12 hours a day?

[Deenem]

Was just wondering....

I shower in the evening, so if I turned my geyser off just after I showered, then turned it back on the next morning before I went to work, I'd always have hot water when I needed it, but I'd cut my electricity usage on my geyser by half, Right?

[alf101]

Was just wondering....

I shower in the evening, so if I turned my geyser off just after I showered, then turned it back on the next morning before I went to work, I'd always have hot water when I needed it, but I'd cut my electricity usage on my geyser by half, Right?

Do u shave?

[Gunny]

Not by half. Since the geyser is not keeping the water nice and warm all day you use more energy at switch on to get it up to temp. In summer you should see a decent saving in winter not so much especially in JHB, but a geyser blanket and some thermal stuff in your ceiling should help

[bodhi]

currently doing this - my geyser is switched off for about 10 hours.

[stoke]

I'm waiting for Eksdom or Governmint to actually prove that this is not an exercise in futility.

[Deenem]

Do u shave?

Yes, in the shower.. 2 birds, 1 stone...

[Deenem]

the geyser is not keeping the water nice and warm all day you use more energy at switch on to get it up to temp

It's been along time since I was in high school but... whether it's turned on or off the water is losing heat at the same rate, so warming it up from cold is the same as keeping it warm?

[Gunny]

It was just my observation using a timer only resulted in minimal energy saving not 50%. Geyser blankets and insulated cielings helped more.

[SoftDux-Rudi]

Think about it. If the kettle is hot already, how long does it take to boil the water?
Let the same kettle & water stand for 10 hours, and then boil it. It takes longer, right? Why? Cause the water is much colder, and it needs more energy to heat up.

So, how will you save by switching the geyser off? During the day, the sun beats down on your black roof and form a sauna in the ceiling, which helps with geyser keep it's temperature and thus use less electricity.

[Freshy-ZN]

This whole switching off the geyser story is utter rubbish if you ask me. Rather set the thermostat to 55 and leave it on all the time.

[Scooby_Doo]

i think the best would to shower at like 9-10 just before bed then turn it off and then only turn it on when you get home at 5 or 6 the next day.

[Moederloos]

Please note:
DO NOT DO THIS IF you have a ripple switch.
It just does not work.

City Power (or your equivalent) has the power to turn off the geyser when it is most needed - there is no guarantee then that you have the geyser ON at the same time they do. You could land up with cold water, because whenever you turn it ON, those are the times CP has it OFF.

A ripple switch is meant to turn the geyser off when CP needs to shed load.

[eltherza]

i think the best would to shower at like 9-10 just before bed then turn it off and then only turn it on when you get home at 5 or 6 the next day.

Problem with that is that it's using power during the day... when everything else is on. Rather have it get hot overnight when there isnt such a demand for power.

[ajax]

You will save the amount of electricity equivalent to the amount of heat that is lost through the imperfect insulation of the geyser. If the geyser was perfectly insulated, switching it on/off would you save you nothing.

Newer geysers are very well insulated, so you wouldn't save much. Older geysers, especially those ones with just a lid on top, are extremely wasteful in terms of heat, so you would save a lot there.

As mentioned, best is to turn the temperature down, in summer I think one can get away with 45 degrees. But a timer set to heat the water in off peak times would help Eskom in terms of reducing "peak demand". I did hear it costs about R500 to install one so I don't think there will be too many people doing that as the altruism towards Eskom is at an all time low.

[Robin Hood]

Yes, in the shower.. 2 birds, 1 stone...

Thats what i do too...the facial hair is also nice and soft then...saving you on blades ;)

[CathJ]

Don't forget that normal geyser switches are not meant to be switched on and off frequently - the switch tends to break if used frequently.

Rather install a timer, or an isolating switch. Of course, either of these (or replacing a broken switch) will require an electrician, so it's not quite as easy an answer as it seems :(

[LancelotSA]

Think about it. If the kettle is hot already, how long does it take to boil the water?
Let the same kettle & water stand for 10 hours, and then boil it. It takes longer, right? Why? Cause the water is much colder, and it needs more energy to heat up.

So, how will you save by switching the geyser off? During the day, the sun beats down on your black roof and form a sauna in the ceiling, which helps with geyser keep it's temperature and thus use less electricity.

Your argument is shockingly flawed!

The kettle does not attempt to keep the water at a constant 60c (if this is your setting) for the entire 10 hours... your geyser does!

In fact, you think about this.... if you put the kettle on to heat the cold water, how long does it take? As a result how much electricity do you think it used?

Now imagine that same kettle being required to keep that water at 60c for an entire 10 hour period. Which do you think uses more elecricity?

[noxibox]

It's still questionable whether reheating the water whenever the temperature goes below a specified minimum uses more than allowing the water to cool completely, then heating it to the required temperature.

My own experience experimenting with this over the last 15 years is that there is no electricity saving, but a definite increase in hassle levels.

[Freshy-ZN]

My experience is also that there is no noticable saving. It must be said I have a newer, well insulated geyser.

Im still adamant that leaving it on at a reasonable temp setting of 55' is more effective than turning it off for hours at a time.

[Moederloos]

Also made no difference to me.
Years of both have shown me it is pointless.

[Ricard]

I had one of those 'Save 90% electricity' geyser timers installed a few years back.... It was set up to switch the geyser on 1hr before hot water was typically needed..

Net Effect on electricity bill ... Zero! Nada! Zilch! Well, I am sure there was a difference, but I could not see it.

[Freshy-ZN]

I see an interesting trend developing which basically proves Eskom is talking yet more twaddle when they advise us to turn off our geysers.

[Scooby_Doo]

well not really a lie eskom just wants us to turn them off to move load from peak time to non peak time so that loadshedding can be avoided. ie if peak is 5-8 then turn the geyser off then and let it reheat the water from 8-10 for example. Not going to save money or power in terms of totals but will reduce peak load.

[Moederloos]

I see an interesting trend developing which basically proves Eskom is talking yet more twaddle when they advise us to turn off our geysers.

Oh - don't get me wrong.
It saves power in peak times - by you only heating it off peak.
It does not however, save power overall - it just transfers power load to other times.
Which is what the ripple switch does.

EDIT: It is important to take this in context with the "sleep earlier" thing.
Having a light or TV on at night is not going to solve the peak load shedding.
I believe that they are trying to rebuild coal stocks and allow for night time maintenance - hence the desire to get you to use NO power at night.
In this context, the "switch our geyser off" ploy is nonsensical.

[noxibox]

They must call it what it is - load shifting, not try to sell us nonsense about it saving us money.

[Ricard]

well not really a lie eskom just wants us to turn them off to move load from peak time to non peak time so that loadshedding can be avoided.

Ripple switches have been running in Gauteng for years .. why doesnt the council switch the geysers off then!

[HavocXphere]

Never mind 12 hours. Those things hold their temp for ages.

I tried it recently:
24 hours=still too hot to hold your hand in it
48 hours=still plenty hot for a nice shower

Admittedly that is on a geyser that is set very high (That particular geyser is now off 24/7).

Anything under 36 hours is hardly going to result in real reheating.

The only options I see are switch it off 24/7 or switching it off during the peak times to help Eskom spread the load over the day.


Ripple switches have been running in Gauteng for years .. why doesnt the council switch the geysers off then!
Our house has a switch like that...but Eskom neglected the infrastructure there too. So it has not worked for years.

[Moederloos]

Ripple switches have been running in Gauteng for years .. why doesnt the council switch the geysers off then!

Ours actually work!
Can you believe that?

Off every morning from 6am to 10am.
I have not checked lately - but I will make a point of doing so when we are at Stage 2 and see if it is off or on.

I will report back ASAP!

I have always been a staunch supporter of ripple switchers. I have defended them on this site too.
To me, the most logical, and least disruptive power management system there is.

[Scooby_Doo]

like in a perfect world everyone in the contry should turn off their geysers now till about 20:30, but yeah not so perfect.

[Moederloos]

like in a perfect world everyone in the contry should turn off their geysers now till about 20:30, but yeah not so perfect.

I cannot.
If I do, I may lose the "window" that City Power has the ripple switch set to ON.

Ripple switches are the only way - you and I cannot tell when the "best time" is. For all you know, half the grid could go down later tonight when you decide to switch your geyser on. :D

[budgie]

I am continually amazed that there are so many people who think that it does not take continual energy to keep an object at a temperature higher than -273 celsius (the absolute lowest temperature possible). This should have been taught to us all in standard 5. Thus it cannot be cheaper to keep your geyser switched on than to turn it off. One person reminded us that the only difference that a blanket makes is that it slows down the transfer of heat energy from the geyser to the outside world. This transfer is happening whether the geyser is on or off. Either way you have to put energy back into the system (as electrical energy) in order to keep it hot. The parallel example is that it takes far less energy to put your suitcase down when waiting for the plane and pick it up when you go than to hold it up all the time. Come on people, stop being stupid. If you don't believe me, do a controlled test at home. without changing any of the other elecrtrical usage patterns of the house, go away for 12 hrs with the geyser left on and do the same the next day with it off. At the same time on each day have a hot shower of the same temperature, On the switch off day, turn the geyser on about a half hour before you shower and then off before you get into the water. Take KiloWatthr readings before and after each day and then calculate.

[budgie]

Another way of understanding the geyser issue is to realize that Earth itself is like a huge geyser. It only stays at it's average warm temperature (necessary to sustain life) by being CONTINUALLY heated by the sun. If the sun were turned off for a million years and then turned on again the earth would cool down and then warm up again back to its old operating temperature. The net result would be a huge saving on the Earth's electricity bill.
Global warming is similar to having a geyser blanket. The added CO2 in the atmosphere makes it more difficult for heat to escape and the planet cools down slower or, if heated by the sun, will heat up a few degrees.
The only reason we want to have the geyser on is to have the privilege of being able to shower whenever we choose. Privileges always cost more.

[flarkit]

Timer-switch installed 2 weeks ago and seems to be working fine. Next step is to find a good geyser blanket in Pta, that hopefully doesn't cost more than R250!

[Markc]

What about gas as an alternative to using electricity to heat water. Gas has been successfully used around the world for decades. Why do we still burden the national power grid with heating of water, and cooking.

Surely both of these acts are much more efficient when using gas instead of water. When living abroad and using gas to cook, heat the water, and heat the house (well heats the water in the radiators...), not once did we ever run out of hot water (5 ppl living in the same house, all leaving for work at 7am.... one water heater 1/4 the size of a traditional high pressure geyser).

We are looking at how to fix what we have, instead of looking how we can go forward with alternative energy sources!!! :eek:

[Frankie]

My experience is also that there is no noticable saving. It must be said I have a newer, well insulated geyser.

Im still adamant that leaving it on at a reasonable temp setting of 55' is more effective than turning it off for hours at a time.

This is my experience too - cold shower because someone forgot to switch the geyser back on - a timer would help here, but still I don't believe there's a worthwhile saving.


Ripple switches have been running in Gauteng for years .. why doesnt the council switch the geysers off then!

When I stayed there they did use them - I defeated it because the family was large then and there was insufficient hot water for all to shower.


What about gas as an alternative to using electricity to heat water.

My parents always had gas stoves with instant water heaters (Junkers) - we had 4 X 100lb cylinders outside.
Even the electric instant water heaters would save money.


I think improved geyser insulation and temperature set point reduced to 55~60 C is the key, as many have already suggested - the better insulation reduces heat loss and the lower differential temperature between the geyser and ambient reduces transfer.
If the power is left on and the geyser is at temperature the thermostat will not apply power to the element until it reaches the lower point of the thermostats hysteresis which may not occur for a few hours and this time depends on the thermal insulation.
The typical hysteresis of the thermostat is 5~8 C , so if it's set at 60 the power will only pass when the temperature drops to say 57 C and then turn off again at say 63 C.

[JungleRumble]

Geyser on - geyser off - the issue here is not a saving on YOUR monthly bill. It is about removing excess load during peak times.

Use a timer (with back-up battery), Isotherm geyser blanket (costs only around R100, and it is itch-free) and remember to insulate at least 1.5m of the incomming and outgoing piping too. That's actually where most of the heat loss occurs (hot water pipe).

[Albereth]

Yes, in the shower.. 2 birds, 1 stone...

What is the stone for?

[Albereth]

Another way of understanding the geyser issue is to realize that Earth itself is like a huge geyser. It only stays at it's average warm temperature (necessary to sustain life) by being CONTINUALLY heated by the sun. If the sun were turned off for a million years and then turned on again the earth would cool down and then warm up again back to its old operating temperature. The net result would be a huge saving on the Earth's electricity bill.
Global warming is similar to having a geyser blanket. The added CO2 in the atmosphere makes it more difficult for heat to escape and the planet cools down slower or, if heated by the sun, will heat up a few degrees.
The only reason we want to have the geyser on is to have the privilege of being able to shower whenever we choose. Privileges always cost more.

Umm - we need to use the Earth every day. Sort of like the geyser. Can you imagine the smell if we didn't bathe for a million years.

But if you are going away for several days, then it does make sense to turn off your geyser.

Rather save power by unplugging your TV and all those cell phone chargers.

[Albereth]

Oh - the simple answer why high school science doesn't apply.

When you shower you use only a portion of the water in the geyser. Unfortunately you have no way of heating just the part you are going to use - you heat all the water in the geyser. And by and large, the water all heats up equally.

I could go into a long explanation about heating and cooling not being a linear equation and a whole load of bull about thermodynamic properties of the various materials, heat transfer and heat radiation. At school, science was to a large extent an extension of simple mathematics, not the complex multi-factor modelling that you really need to apply.

I can't really say that the gas heaters that zap the water in the pipe as it flows into the bath is more efficient. It is slower than if you had hot water on demand and for you time may be more important than the cost of heating. We all have different needs and circumstances so the water heating systems that works for you may not be the same for me.

[greg_SA]

You will save the amount of electricity equivalent to the amount of heat that is lost through the imperfect insulation of the geyser. If the geyser was perfectly insulated, switching it on/off would you save you nothing.

Newer geysers are very well insulated, so you wouldn't save much. Older geysers, especially those ones with just a lid on top, are extremely wasteful in terms of heat, so you would save a lot there.

As mentioned, best is to turn the temperature down, in summer I think one can get away with 45 degrees. But a timer set to heat the water in off peak times would help Eskom in terms of reducing "peak demand". I did hear it costs about R500 to install one so I don't think there will be too many people doing that as the altruism towards Eskom is at an all time low.

Agree 100% - Most new geysers are VERY well insulated - Ours hardly even feels warm on the outside.

Also, we have a ripple switch - do they ever get used?

[lcbxx]

There is a big debate around what happens to to water in the geyser when you switch it off etc etc where Moederloos answered the question about twice already:
There will be little to no difference in you electricity bill if you switch your geyser off at peak times. Eskom sold this bullshyte to its customers because it has electricity demand problems.

And for those who are trying to conserve electricity, like myself: Everything you and I save is passed to Eskom's industrial customers and neighboring countries who have contracts with Eskom and who can't give a shyte about supply excuses - they have a contract and if Eskom cannot supply, Eskom pays crippling fines. This is a fact that has been proven twice already.

[hierts]

Geyser on - geyser off - the issue here is not a saving on YOUR monthly bill. It is about removing excess load during peak times.

Use a timer (with back-up battery), Isotherm geyser blanket (costs only around R100, and it is itch-free) and remember to insulate at least 1.5m of the incomming and outgoing piping too. That's actually where most of the heat loss occurs (hot water pipe).

Agreed.. but, why help the guys that double the price, dont do their job, tell you its your fault for using too much of their product, grabs a nice fat bonus and still "preemptive loadshed" you. Im not against doing my bit to help, I did, but when Im told that its my fault they cannot provide enough electricity I gave up. That and the cold showers.. :D

[Albereth]

There is a big debate around what happens to to water in the geyser when you switch it off etc etc where Moederloos answered the question about twice already:
There will be little to no difference in you electricity bill if you switch your geyser off at peak times. Eskom sold this bullshyte to its customers because it has electricity demand problems.

And for those who are trying to conserve electricity, like myself: Everything you and I save is passed to Eskom's industrial customers and neighboring countries who have contracts with Eskom and can't give a shyte about supply excuses.

Yes - you are quite right - why should we bother to conserve.

Thnig is, there are some people who may want to save themself some money. Switching your geyser on and off doesn't save money - it probably costs. But turning the TV off and unplugging cell phone chargers will save money.

Eishkom are already dealing with us annoying consumers by forcing us to not use their product. I am quite happy not to give them any more money than I possibly ever have to. Not because I care about the environment, not because it's the socially expected thing to do - but because I a damned if I will contribute one more cent to some idjit's undeserved bonus.

[lcbxx]

Yes - you are quite right - why should we bother to conserve.

Thnig is, there are some people who may want to save themself some money. Switching your geyser on and off doesn't save money - it probably costs. But turning the TV off and unplugging cell phone chargers will save money.

Eishkom are already dealing with us annoying consumers by forcing us to not use their product. I am quite happy not to give them any more money than I possibly ever have to. Not becaue I care about the environment, not because it's the socially expected thing to do - but becuase I a damned if I will contribute one more cent to some idjit's undeserved bonus.
Don't get me wrong, I'm all for conserving energy and operating more efficiently, but I cannot stand being lied to so that others can reap the benefits.
Being a democratic country (albeit a uniquely democratic country), if the Government is to blame for the energy crisis, they are the ones who should subsidise the Eskom increase.
Then again, being such a unique democratic country, it seems that the voters are the ones that foot the bill for our democratic Government's mistakes.

I wish the masses who voted them into power will be told (and convinced) what their beloved Government did (and still does) with their hard-earned tax money. They obviously don't know since there aren't any violent protests at the parliament buildings, with burning tires around Alec Irwin & Jacob Zuma's necks...

[JungleRumble]

Agreed.. but, why help the guys that double the price, dont do their job, tell you its your fault for using too much of their product, grabs a nice fat bonus and still "preemptive loadshed" you. Im not against doing my bit to help, I did, but when Im told that its my fault they cannot provide enough electricity I gave up. That and the cold showers..

It seems that you Jozi guys are being whipplashed by Excusecom. At least the Cape's sheeding schedule seems to be according to the published schedule.

Still - rebelling against the Excusecom fatcats will not solve the problem,

[Albereth]

@Icbxx - you make an interesting case for the voting to not be confidential. Thoise who voted for the current bunch of idjits should share the costs amongst themselves.

That might convince a few people that they should think a bit before they vote.

If shareholders of a company put the wrong directors in place they get burnt. Also, if directors act like idjits - they can get sued too.

[alanB]

Hi

We've just posted our latest geyser test. We simulated a geyser time switch to try and understand how that would help.

http://www.powersaving.co.za/index.php?q=con,65,%20misc

[Gnome]

Had a talk with the plumber the other day, he basically confirmed my story that a modern geaser has such good insulation you're unlikely to notice a difference in usage. The reason being:

A modern geaser loses 1 degree celsuis every 5 hours (if I remember correctly), the thermostat sits where the water comes into the geaser, if it drops in temperature it switches on for a short time and off again. Although heating the water all at once = higher thermodynamic efficiency, you're not gonna save that much electricity.

Oh and on the topic of ripple switches, the reason the Government don't use them is because they don't work, at least some houses don't switch off and sometimes they don't switch back on again, then they have to come out to your home to fix the problem, in the end they've lost way more than they've gained by constantly going through that exercise.

[Graham2107]

I can't believe that Albereth is making a comparison in saving electrical energy between a geyser and a TV and cellphone charger.

1 x geyser = 2KW (3KW on larger geysers)
1 x TV = 50watts
1 x plasma TV = 350watts
1 x cellphone charger = 4watts

Gnome's electrician needs to go back to school if he thinks that a geyser cools by 1DegC every 5-hours !! Come on, be real. If the internal water temperature is say 50Deg C and the ambient external temperature is say 20Deg C that is a thermal differential of 30Deg C. Try the experiment yourself in a cool box and measure the water temperature after 5-hours, it won't be 49Deg C !!

By the way - ripple switches are very reliable. Ask Ballito Municipality who have been using them for years.

[Turiko]

By the way - ripple switches are very reliable. Ask Ballito Municipality who have been using them for years.


Modern ripple switches are very reliable yes... we often talk about old ones, like what we have here in Gauteng, that are antique and tend to catch fire.

The thing is, for me, my geyser remains hot enough for me to bath after 1 full day. When I went to Durban for the weekend in April I turned the geyser off when we left. When we got back it was still warm. Not hot but still sufficiently warm to use to wash the dishes.

[Graham2107]

So you would advocate that turning the geyser OFF does in fact (a) save electricity and (b) have little effect on the water temperature ?

[Turiko]

Well in my case doing so saved me some cash on my electricity bill. Saved about R80. It is hard to put a number on it because I was home when I did this experiment and I was using other appliances a lot more such as my PC and the lights and power tools.

Over time the geyser gets cold yes. It does lose heat but not at a fast rate due to the insulation. But over a short period such as 8-12 hours I cannot tell the difference apart from about 8-10% less total "hot" water volume. But the water that comes out still burns if you touch it. Honestly after 8 hours of being off I can still have a freeking hot shower if I want no problem and if you would like to see this take place PM me and I can gladly demonstrate :)

It of course depends on the age and condition of the geyser. Mine is just over 3 years old. So with a 20 year old geyser (one of those old white ones) I'd expect a helluva lot more heat loss. Having one of those is a risk anyway, it can say bye-bye at any time leaving one with extensive water damage in the house.

[Graham2107]

I am surprised at how little energy you saved as some manufacturers claim up to 45% ?!? perhaps to take with the proverbial "pinch of salt".

What system did you use ?

I am keen to persue this avenue of savings as we have two geyers on our property and if we can save some "beer money" then all the better for that.

[Turiko]

I am surprised at how little energy you saved as some manufacturers claim up to 45% ?!? perhaps to take with the proverbial "pinch of salt".

What system did you use ?

I am keen to persue this avenue of savings as we have two geyers on our property and if we can save some "beer money" then all the better for that.

I am not using a system at present. I did that manually because my system is under development.

Well I am pursuing this avenue myself, I am designing DSM systems and applications. Maybe you might be interested in my work and the products I am developing. I have asked twice here for help with the testing but so far, no takers.

[Graham2107]

I have developed my own geyser timer using a Microchip PIC.

I have been developing electronic systems for "non off the shelf" applications for years now and I was just keen to build something for myself to "see" if all of these claims were valid.

My systme runs on a RTC and has two time period for 7-days/week.

Typically OFF (default but user adjustable via a simple keypad and LCD display) for 09h00 to 15h00 and 21h00 to 03h00.

I have a "day ON/OFF" selct so that, especially if you have visitors you can switch the timer OFF for the entire day.

I have yet to install it but works well on the bench.

I am always keen to investigate what other people are doing and so please forward me some details on what you are up to.

You can pm me on projects@cellcomm.co.za or via an enquiry on my website at www.cellcomm.co.za

Graham
Durban (a very cold one)

[SlyFly]

Switch the geyser of in the evening before you shower (Depends on how many people in the house) Then the next morning you can switch it on again, if only one person showereed the evening the water will still be pretty warm and it wont use that much electricity to heat it up again... Once a geyser is warm it doesnt use THAT much power, but it uses a lot of energy if you keep on using warm water, because cold water gets added to the warm water and that needs to be heated up again?

Thats what I do :P

[JungleRumble]

I have seen an IR photo of a modern geyser. Will try and find a link to it.

It is true that the geyser itself is very well insulated - and 95% of the geyser "body appears cool on the photo. The heat loss is very evident close to the outlet pipe, and around the outlet pipe itself.

[Turiko]

Well that would be correct, if you "felt up" your geyser you'd draw the same conclusion. My outlet pipe is about 10mm DIA so the surface area for heat loss is less than what would be for those who still have lead piping.

@Graham

I have e-mailed you at said address.. Did you get it?

[Keeper]

Your argument is shockingly flawed!

The kettle does not attempt to keep the water at a constant 60c (if this is your setting) for the entire 10 hours... your geyser does!

In fact, you think about this.... if you put the kettle on to heat the cold water, how long does it take? As a result how much electricity do you think it used?

Now imagine that same kettle being required to keep that water at 60c for an entire 10 hour period. Which do you think uses more elecricity?

for once i can say i agree with U. :eek:

[Mephisto_Helix]

take a reading over a 12 hour period, first with the geyser on and then with it off ......... you only save about one kwh. Do the same with your fridge and prepare to be shocked at how much you can save.

[Turiko]

take a reading over a 12 hour period, first with the geyser on and then with it off ......... you only save about one kwh. Do the same with your fridge and prepare to be shocked at how much you can save.


I seriously doubt it is wise to DSM the fridge... I am sorry but I value my expensive food. I cannot see why the fridge is such a power guzzler. However don't take my word for it and I assume nothing. I will do some tests first before I say anything further.

The supposed savings I got with turning off my geyser were probably affected by the ripple control also, something I forgot to mention.

[Mephisto_Helix]

I turn my main fridge off for 8 hours every second day and the spare fridge off for 12 hours every second day .... is cold enough to keep it cold for that period (no spoiling at all). Save about R200 a month on that alone, I kid you not.

[bekdik]

We have received a number of similar enquiries and the info below will hopefully give a full explanation.

Eskom has requested us all to switch our geysers off during the day but this is primarily aimed at making more energy available for other consumers such as hospitals, tertiary institutions, commerce, etc. Unfortunately, this is not guaranteed to reduce household electricity accounts.

The energy wasted in geysers has been a topic of discussion in technical circles ever since geysers were first introduced and there are still many divergent views on the matter. However, the ideas which seem to me to be most logical are as follows:-

Geysers in houses are usually installed in the roof. This area is very hot, particularly during the day in summer, so there can’t be a lot of heat lost from the geyser during the day as the ambient temperature around the geyser is not far below the 50 / 55 degree temperature of the water in the geyser. Also, remember geysers are well insulated in order to limit heat losses.

When a tap is opened, hot water flows through the pipe and obviously stops once the tap is closed. The water remaining in the pipe is hot but soon cools down and the energy originally used to heat the water is therefore wasted. If the distance from the geyser to the tap is long, there will be more water in the pipe and therefore more energy will be wasted as the water cools down.
The waste of energy is unavoidable but can be reduced by limiting the number of times the tap is opened and by insulating the hot water pipes for the first 4 or 5 meters from the geyser.

The golden rule is: - Electricity consumed by hot water systems will only be reduced if the household reduces their use of hot water or improves the pattern of usage.

It is also most unlikely that energy usage will decrease due to switching geysers off during the day. Monthly electricity accounts depend not only on the energy consumed but also the period over which the consumption is measured. Meters are not always read on the same day of the month and the number of days between readings could vary between 27 and 34 which has a significant effect on the billed consumption.

Installing a solar water heater is a good idea but the payback period is not always as good as the manufacturers claim as savings depend on when and how much water is used. Please note that a timer may be affected by load shedding unless it is equipped with a back up battery.


I asked a municipality whether switching a geyser off would save on electricity usage. (My Bold text)

[Turiko]

I turn my main fridge off for 8 hours every second day and the spare fridge off for 12 hours every second day .... is cold enough to keep it cold for that period (no spoiling at all). Save about R200 a month on that alone, I kid you not.

OK what I am going to do is I am going to put a meter on my fridge. I will do that probably tonight or sometime before the weekend and post the results here on an ad-hoc basis. Let's see what kinds of usage a fridge has and calculate what kinds of average savings we can expect.

[psc]

@Turiko

AlanB has already got a study on a fridges power consumption, if I recall properly it is in the region of 2.X kW/h per day (+- R1.00) .

http://www.powersaving.co.za/index.php?q=con,50,%20misc

[Moederloos]

I turn my main fridge off for 8 hours every second day and the spare fridge off for 12 hours every second day .... is cold enough to keep it cold for that period (no spoiling at all). Save about R200 a month on that alone, I kid you not.

There is simply no way in hell you could save that much unless your fridge is badly sealed or an archaic monster.

I only use R500 a month on electricity, and have 3 fridges, a deep freeze, a home office, a geyser that came off the Titanic, a pool and the usual assortment of other goodies.

[Turiko]

@Turiko

AlanB has already got a study on a fridges power consumption, if I recall properly it is in the region of 2.X kW/h per day (+- R1.00) .

http://www.powersaving.co.za/index.php?q=con,50,%20misc

I realise that, and I also suspect the figure to be about R1 a day to run. But it would be interesting to see what happens, considering mine seems to run a lot.

My electricity bill averages around R300 / month and that's with several servers I run 24/7 and a home office. My geyser does tend to be power hungry because I can save money by turning it off. The other problem is my stove is a piece of kuk. I have a brand new one but I need to finish the counter tops before I can put it in

[Graham2107]

Turico

So why don't you put a geyser timer in circuit if you think that your geyser is guzzlin all the power ?

For stove tops I think that this new magnetic (?) based system is really good. Big problem is that they are expensive to start with so you have really negated the original idea of saving money !

[Turiko]

I am developing a timer/ripple receiver combo unit.

[psc]

For stove tops I think that this new magnetic (?) based system is really good.

Induction cooking, yes its really very efficient (cant use all pots though) :(

[Mephisto_Helix]

There is simply no way in hell you could save that much unless your fridge is badly sealed or an archaic monster.

I only use R500 a month on electricity, and have 3 fridges, a deep freeze, a home office, a geyser that came off the Titanic, a pool and the usual assortment of other goodies.


I realise that, and I also suspect the figure to be about R1 a day to run. But it would be interesting to see what happens, considering mine seems to run a lot.

My electricity bill averages around R300 / month and that's with several servers I run 24/7 and a home office. My geyser does tend to be power hungry because I can save money by turning it off. The other problem is my stove is a piece of kuk. I have a brand new one but I need to finish the counter tops before I can put it in

well when you have a monthly bill of 1.2k or above (I've posted about it in this section somewhere), /me had to find what was causing the high bills. Through putting off various things, it came down to the fridge being the main culprit/guzzler. Personally, I don't agree with that R1 a day story ......

[Turiko]

Well, by testing we can see what is going on. it doesn't help to speculate on a forum

[Paulr]

Induction cooking, yes its really very efficient (cant use all pots though) :(


I remember seeing those on Beyond 2000 (I think) about 15 years ago or so. The way they work makes a lot of sense.

Are units like that available yet? (And at a decent price, might I add)...

[Turiko]

AFAIK they are available, however the price tag is :sick:

[Moederloos]

well when you have a monthly bill of 1.2k or above (I've posted about it in this section somewhere), /me had to find what was causing the high bills. Through putting off various things, it came down to the fridge being the main culprit/guzzler. Personally, I don't agree with that R1 a day story ......

More a case of awareness than the fridge imho.
A simple awareness of consumption leads to things like turning off lights, TVs and so on.
Take an average 100W bulb left on for 2 hours a day, unnecessarily. Thats 200W a day or 1KW in five days, or 6KW a month, or around R3.
We have 5 40W downlights in the kitchen, so that is 200W "a time", or R6 a month if left on without reason. Multiply out for lounge, diningroom and 3 bedrooms with similar consumption, and we have 6*6 = R36 a month that is pure waste. Everyone in my house knows they will face the wrath of M. if they leave lights on, so a saving of R36 easy - which on my bill is around 7%.
Just on lights.

My opinion on the fridges? They have caused an awareness - and the result is a saving for you. The fridges are just the catalyst. (perhaps people have stopped standing in front of an open fridge saying "I don't know what I feel like" for 20 mins) :D

[BTTB]

We have two Geysers on our property. One feeds the bathroom and the other feeds our private kitchen, wash room and staff kitchen.

I installed two electronic timers and set them up as follows:

Geyser 1:

05h30-08h00
09h30-12h00
14h30-16h30
18h30-22h00

Total Hours Geyser 1 - 10.5

Geyser 2:

06h00-09h00
12h30-14h00
17h00-18h00

Total Hours Geyser 2 - 5.5

In summary the two geysers potentially run for less hours than one geyser at 16 hours in total per day.
This ensures hot water to the kitchen during the day and at supper and a steady supply of hot water for the bath room for most of the day.
I haven't noticed a drop in my Electricity Bill, probably negligible, but one of my main reasons for installing the timers was to shed my own load so that during the day my total usage on the property should not exceed 60 AMPS otherwise the board would trip.

[Moederloos]

I have often considered installing just a gasheater for water for the kitchen and guest shower.
Anyone think that will be "cost effective"?
The kitchen uses a lot of hot water in a distributed fashion - my thinking is that this constant use means the geyser stays on for more than it would with a gas heater.

EDIT: The (non-cost-sensitive) advantage of course is hot water in the shower and kitchen when the power fails or the ripple system goes "belly up" again.

[kaspaas]

Turn the thermostat down until you don't need to add cold water.

It is amazing how much electricity you will save.

[Moederloos]

Turn the thermostat down until you don't need to add cold water.

It is amazing how much electricity you will save.

This has been discussed before - and the difference in opinion heated (groan).

By only using hot water, you use more of the hot water. I for one do not think that would save much.
Also, for people with smaller geysers, they could run out.

[psc]

Turn the thermostat down until you don't need to add cold water.

It is amazing how much electricity you will save.

And you will probably die from legionaires disease ;)

[Turiko]

Gentlemen,

What I propose is that we take this rationale a bit calmer here. I get the feeling that things might get a bit tense here.

Instead of thrashing it out on a forum why don't we work together and test these things on a larger scale and with some form of calibrated instrumentation. That way we can compile a definitive list of what the savings are and what the savings aren't for what circumstances and appliances involved.

As you know my pet project involves DSM and I have metering that I can use to test these things. Why don't we collaborate?

[Lord Anubis]

Well in my Vaal house I put a pay as you go meter. I started loading it in R1000 increments for the day when we get rationed. I have now a full meter 9999kW cost me about R5000 back in April.

In my future I see aircons in summer and heaters next winter and middul finga to the man

[psc]

Well if you look at the manufacturers websites, most have the energy consumption figures.

They seem to vary between 135 and 340 kW/h per anumn depending on size and whether they are fridge, fridge freezer or freezer.

[Moederloos]

Well if you look at the manufacturers websites, most have the energy consumption figures.

They seem to vary between 135 and 340 kW/h per anumn depending on size and whether they are fridge, fridge freezer or freezer.

so, 0.3 - 1kw per day

[psc]

Yes, they are however modern units and have either an A or A+ energy rating

[Maginxa]

I am about to build a house and it has been suggested to me that i put in 20-30L geysers, one in each of the 2 bathrooms (we shower only) and one in the kitchen, perhaps even a smaller one in the kitchen. Can anyone tell me whether this would save on electricity. Basically we require 3 hot showers a day and a couple of sinks of hot water, it seems unnecessary to maintain 150L at 55deg for the entire day for this.

[jasondeklerk]

Try installing a Geyser Switch, MUCH MUCH simpler
You can get one on http://www.redgiant.co.za or http://www.redgiant.co.za/index.php?page=shop.product_details&category_id=17&flypage=flypage-ask.tpl&product_id=54&option=com_virtuemart&Itemid=64&vmcchk=1&Itemid=64 , it is about R220 or something and does not fit into the DB Board :p


Geyser on - geyser off - the issue here is not a saving on YOUR monthly bill. It is about removing excess load during peak times.

Use a timer (with back-up battery), Isotherm geyser blanket (costs only around R100, and it is itch-free) and remember to insulate at least 1.5m of the incomming and outgoing piping too. That's actually where most of the heat loss occurs (hot water pipe).

[Hosehead]

I've installed my greyser exposed and outside in the interest of space saving. I asked about insulation but it would seem that it's already insulated inside. EXCEPT for the area around the thermosat. What should I do? These elect bills are eating me alive-o.

[Paulr]

I've installed my greyser exposed and outside in the interest of space saving. I asked about insulation but it would seem that it's already insulated inside. EXCEPT for the area around the thermosat. What should I do? These elect bills are eating me alive-o.

Feel the outside (body) of the geyser - if it's warm it means you are losing heat and a geyser blanket will help.

As for the thermostat area - see if you can get some fibreglass (Think Pink type stuff) and place it over the area. Be careful of not putting something that can conduct electricity there - it can cause unwanted fireworks.

[Morgoth]

Try installing a Geyser Switch, MUCH MUCH simpler
You can get one on http://www.redgiant.co.za or http://www.redgiant.co.za/index.php?page=shop.product_details&category_id=17&flypage=flypage-ask.tpl&product_id=54&option=com_virtuemart&Itemid=64&vmcchk=1&Itemid=64 , it is about R220 or something and does not fit into the DB Board :p

1) nice try advertising your own site, do the math as I posted in another thread and you will see that turning off a geyser costs more money then letting it run.......

now don't come with your expert opinion crap again......

well done bumping a over a year old thread...

[Hosehead]

Feel the outside (body) of the geyser - if it's warm it means you are losing heat and a geyser blanket will help.

As for the thermostat area - see if you can get some fibreglass (Think Pink type stuff) and place it over the area. Be careful of not putting something that can conduct electricity there - it can cause unwanted fireworks.

Thank You kindly. I'll see what I can do...

[Nerfherder]

We have two Geysers on our property. One feeds the bathroom and the other feeds our private kitchen, wash room and staff kitchen.

I installed two electronic timers and set them up as follows:

Geyser 1:

05h30-08h00
09h30-12h00
14h30-16h30
18h30-22h00

Total Hours Geyser 1 - 10.5

Geyser 2:

06h00-09h00
12h30-14h00
17h00-18h00

Total Hours Geyser 2 - 5.5

In summary the two geysers potentially run for less hours than one geyser at 16 hours in total per day.
This ensures hot water to the kitchen during the day and at supper and a steady supply of hot water for the bath room for most of the day.
I haven't noticed a drop in my Electricity Bill, probably negligible, but one of my main reasons for installing the timers was to shed my own load so that during the day my total usage on the property should not exceed 60 AMPS otherwise the board would trip.

You are letting the geysers get too cold, keep them on for longer during the night and keep them off for when they are not used during the day. Then your bill will go down.

[theratman]

I have my 100l geyser on for 2hours a day.Started last month and my bill went from 270 to 160.Water is never lukewarm,always hot.

[Paulr]

Try this one I am selling online.

http://capetown.gumtree.co.za/c-Stuff-for-Sale-general-items-for-sale-Analogue-Geyser-Timer-Switch-W0QQAdIdZ178118282

Dude, please, I bought one of those timers as in your ad's picture for my pool from Mica for R100.... :confused:

[nevinturner]

I have some process knowledge and have done some testing. If you switch off you geyser during the day it has no or little effect because the heat lost during the day while the geyser is off is recovered when you put it back on so no saving. During the day the geyser only switches on and off for very short periods to compensate for the heat loss, so, when you turn it on in the evening it recovers the loss in any case so you can save on not installing a timer as there is no benefit. If you do want to save, change you habits. I used the same amount of power for 1 person’s bath compared to 3 peoples shower.

[cbrunsdonza]

You are letting the geysers get too cold, keep them on for longer during the night and keep them off for when they are not used during the day. Then your bill will go down.

Agree. In the Strand they have installed ripple switches which are only off during peak office hours. Never had cold water in all the years I lived in the Strand. Stayed in 3 different houses.

Currently I've set my geyser to its coldest temp and it also makes a huge diff.

[I am Penguin]

Try this one I am selling online.

http://capetown.gumtree.co.za/c-Stuff-for-Sale-general-items-for-sale-Analogue-Geyser-Timer-Switch-W0QQAdIdZ178118282

What a rip off. OMG! :sick:

[I am Penguin]

Agree. In the Strand they have installed ripple switches which are only off during peak office hours. Never had cold water in all the years I lived in the Strand. Stayed in 3 different houses.

Currently I've set my geyser to its coldest temp and it also makes a huge diff.

You are living in danger. Geysers should never be set lower than the minimum safe 55degrees C. You may expose yourself to a terrible disease.


Turn down the thermostat. Many geyser thermostats (the device that switches off the heating element in the geyser once it gets to the right temperature) are set to 70 C. By adjusting this down to 60 C, the geyser’s electricity consumption can be reduced by 14%. Please note that the temperature should not be set below 55 C to avoid conditions conducive to bacterial growth and diseases such as Legionaires' disease.

Q. What are the symptoms of Legionnaires' disease? (http://hcinfo.com/ldfaq.htm)

A. Legionnaires' disease develops within 2 to 10 days after exposure to legionellae. Initial symptoms may include loss of energy, headache, nausea, aching muscles, high fever (often exceeding 104°F), and chest pains. Later, many bodily systems as well as the mind may be affected. The disease eventually will cause death if the body’s high fever and antibodies cannot defeat it. Victims who survive may suffer permanent physical or mental impairment.

Temperature affects the survival of Legionella as follows:[ (http://en.wikipedia.org/wiki/Legionellosis)20]


70 to 80 °C (158 to 176 °F): Disinfection range
At 66 °C (151 °F): Legionellae die within 2 minutes
At 60 °C (140 °F): Legionellae die within 32 minutes
At 55 °C (131 °F): Legionellae die within 5 to 6 hours
Above 50 °C (122 °F): They can survive but do not multiply
35 to 46 °C (95 to 115 °F): Ideal growth range
20 to 50 °C (68 to 122 °F): Legionellae growth range
Below 20 °C (68 °F): Legionellae can survive but are dormant

[cbrunsdonza]

Oh, the coldest my geyser goes is 65

Interesting post, but then again I don't drink the hot water - got a kettle for that :)

[bekdik]

Powering a geyser off for some period cannot save electricity, yet people continue to claim massive savings. On the radio yesterday a caller claimed that by only switching his geyser on for 2 hours twice a day save 50%.

So what's going on?

I think I have the answer - what's happening is that the temperature of the hot water is dropping as it's not being heated as much as it was and the user doesn't notice that he is mixing less cold water.

If this conjecture is correct, a better solution would be to turn the thermostat down by 5°.

[kaspaas]

There are a number of possible reasons for people getting these results:

The active management of a geyser (switching it on and off) will result in people being more aware of their hot water usage.

Other reasons include leaky hot water pipes and even worse, a leaky electrical circuit.
When the geyser is switched off, the losses due to especially leaky electrical circuits are reduced. Geysers are seldom connected to the eartleakage protection.


Also rodents and insects find geyser insulation nice an cozy, and often the insulation is efffectively a useless mess around the geyser.

People who get such savings, should urgently have there geysers, water pipes and electricity installations checked by competent persons. This is not a DIY job.