Thread: Power Saving on a Hot-water system.

Originally Posted by Disco_owner

Justine;

going back about 12 months , there has been 4 adults living in this house hold , consequently we have noticed a big jump in power usage only last 12 months or so , people having showers everyday , hot water for cooking , cleaning etc , last quarter we used 1902 kwatts of power used
is this norma ? it's highest we've used in any quarter.

I don't know how may kws we use but our bills vary from about $260-290/quarter. That is running the 250L HW system, fridge and freezer, oven, hotplate, computers, crt tv and all lights are fluoros. For two people.
Basically all the normal stuff and we don't have gas anything.

As said above I doubt you would have enough hw storage to be able to take advantage of the off peak power.

I just turned the hw system down from full power (70 degrees) to 60 degrees. So our bills should go down by something.

Originally Posted by Xavie

For a small tank of 125litre it will by default be at peak setting. You can have it on off-peak but you would probably run out off hot a lot water (dependent on your schedules).

If you call Origin and if your street has gas mains you might be best off asking them to install it. They kept extending their free offer of gas installation so it still might be valid. AGL charge 600 buckeroos.

Otherwise going to solar has a huge rebate.

Xav

on OPHW setting the hot-water system relay doesn't kick in , had a power blackout
and the other night and when power came back on the misus went to check why
power ccts had no power and accidentally switched the hotwater cct to OPHW
and 125L tank , it doesn't even heat up water ??????

Originally Posted by weeds

be carefull with doing this, outdoor units are
designed taking into account there is plenty of ventilation, once inside
the house available ventilation is a lot less, pretty sure it is illegal but
in saying that we all do that not quite right.....

just ensure the flame is nice and blue i.e. no yellow in it.

that's something I'd be seriously considering, but I'm leaning more
towards Solar, all your advice regarding Solar hot water has got me thinking.

we don't particularly want a larger hot water system..I'll try changing
the Thermostat temp , ( Thanks for advice Justin )

with government rebate I can't imagine would be that costly ??

Originally Posted by Phoenix

Back to the original question, I presume OPHW is off peak hot water. Shouldn't it be switched to that where the power is cheaper? I thought all hot water units were supposed to be on off peak??

yes, that's right , OPHW is off-peak hotwater

urm , I suspect this is to do with relay in the Hotwater system ,but if the Hotwater Power cct is switched to OPHW we have no hotwater as we experienced a few nights ago.

I suspect once a bigger hotwater system is installed ie a 250L or above then we need to notify the power company and switch back to OPHW to take advantage of cheaper OPHW rate.

Originally Posted by waynep

Highly recommend solar- where you are you should get a good percentage of your hw heating from the solar.
We put in a SolarHart with electric booster in our last house ( no gas supply ) and were very happy with it.
When the gas storage one packs up in our present house it will be replaced with a solar system with gas boost.
If you're prepared to time your hot water use a bit better ( eg have showers and clothes washing at night when the sun heated water is still at its hottest ) you can make even bigger savings.

Also go through all your rooms and see how much stuff there is on "standby" ( or just left on all the time ). Try and encourage people to switch off things at the wall or main switch. If you turn off as much as you can and go and look at the meter it should be ticking over very slowly. If it is still whizzing around there is something "rogue" sucking power.

If you have a solar system with an electric boost (as I did in Yass), my experience was that the best time for showers and big loads of washing was in the morning.
If you drain your hot water in the evening, the electric booster heats the water over night. Then when the sun comes up next morning, the water is already hot.

On the other hand if you don't use a lot of hot water at night, the booster doesn't do much overnight because the water is still pretty hot. When you drain off hot water in the morning, solar energy is available to heat the water, so you don't use the booster as much.

I suppose there is some combination of automatic and manual overide on the booster that could make a different regime better, but with the Solarhart setup I had, that worked best for me (or at least it did when I could convince SWMBO to operate that way).

Of course when we moved out of town and had a heat pump solar system, it was a bit different. It could be snowing in the middle of the night and the heat pump was still heating the water. Our system didn't have an electric booster. On that model, so few people were bothering to connect it that they no longer fitted a booster so it relied completely on the heat pump.

I believe the heat pump solar systems are the most efficient. Unfortunately they are also the most expensive.

I saw this on a program a little while back. Seems interesting, but a very amazing claim!

http://www.youtube.com/watch?v=yh_-DUKQ4Uw

From a sparky point of view.

The Off Peak Hot Water is designed to take advantage of the power generated during off-peak peiods. The only spots its really used now are in areas without gas, and even then some of the new rinnai/bosch instantaneous heaters are efficient enough to run off bottles. 125L is really too small to take advantage of off peak. The common way is to have about a 300L Storage tank with off-peak element in the bottom and a booster in the top. During OP times the bottom element heats the water, as the water heats it rises to the top, thus giving a full tank of HW heated at a cheap rate. If you use all that water, the top element kicks in and only heats the top section.

The old style meters used to use a time clock to control when the OP was active, problem with this was that after a blackout, the SEC had to go around and reset all the time clocks. With a modern meter they just send a pulse down the line at anytime whenever there is a power surplus and this activates all the Off Peak equipment.

Seeing as you already have off Peak and No gas, I would get a 300L electric system with boost, or maybe a solar with booster.

My two cents

Stu

well firstoff all, a 125L hot watr system is not nearly enough.
you options are
*put a bigger eletric hws in and ou it on off peak (my advise to you)
*put a gas instantanios in. (Will cost more to run than what you have)
*put in solar (good potion, but costs $3-$4k after rebate)

just my 2cents
cheers steve