An Electric Water Heater money saving question...

[Inchworm]

I was toying around last month with an idea to save on electric bill.

I flipped water heater off at the breaker. Well, I forgot about it really. A few times I suffered through a cold shower. The first one wasn't so bad. It was turned off for about 10 days.

My usage is at a record low. (I've been working on this of late)

My question is...

Would it cost more to heat the water up daily if I turn off at 10pm and on at 5pm the next day, or would it cost more for the heater to maintain the constant temp all day?

:shrug:

:hi:

[Captain Hilts]

1. All over the world people use hot water heaters that are solar powered. Get some solar cells

on your roof.

[Inchworm]

2. Trying to save money not spend it :)

My greenhouse is sucking at my purse as we speak :D

:hi:

[Schema Thing]

3. I think that would definitely save you money

you might think about using a timer on the water heater to automate the process for yourself.

[Inchworm]

4. I'll test manually

I was just wondering if any frugal or green types do this and what results they've had.

:hi:

[HopeHoops]

5. Have you thought about on-demand heaters?

They're very practical for sinks, but not so much for bath and shower use. They basically heat the water on the way to the faucet and aren't much bigger than a garbage disposal.

As for heating it, if you don't plan to use hot water for a few days it is economical to shut it off. It takes about 2 hours to fully heat a cold tank, but only about 15 minutes to heat a refilling tank. It is a similar question to turning the heat/AC off during the day. In general, it is more efficient to maintain a stable temperature than it is to take something from one extreme to the center.

We use a window AC unit in one room (we have hermit crabs) and save a LOT of money by not using the whole house AC. We use open windows a lot. You probably have to try to experiment with that and by "experiment" I mean check the settings on your electric meter, keep a log, and compare the usage over a period of time. Individual results might vary.

[Inchworm]

6. Those are gas?

That seems like it would be my best option for that if I were to buy a new system.

For now, I'm simply deciding ways to make June's bill even less.

:)

[HopeHoops]

8. No, electric.

It is just a small canister that fits under the sink. It has a mass of copper tubing in it and heating elements and essentially the water enters cold and comes out hot - good enough for a sink. A friend of mine uses one and he says it delivers hot water much faster than waiting for the whole-house system to clear the cold water. It is especially good for sinks that are physically far from the main heater. It feeds off the cold water pipe so the hot water pipe isn't even necessary.

[Inchworm]

9. Cool!

I'll look into this.

Then I'll have to initiate designated bath/laundry days for when to turn the big one on.

:P

[HarukaTheTrophyWife]

11. Most of the time, you can just wash clothes in cold water

Saves quite a bit of energy. We only use hot water, if something particularly nasty belonging to one of the dogs needs to be washed.

[Kali]

15. there are gas ones too

[TreasonousBastard]

It depends on how well the heater is insulated and...

how fast it loses its heat.

If it maintains temperature fairly well it might not make much of a difference, since it won't be running much overnight anyway. If it loses a lot of heat fast, it's still kind of tough to calculate the saving, if any, because it will be running off and on vs steady on at full power for a shorter time. The tank size can make a difference, too-- you're heating a larger volume of water, but a larger volume of water loses heat more slowly.

I would probably try wrapping the thing up in more insulation before trying anything else. If you can get your hands on some gadget to measure current flow, that would be handy. A clamp-on ammeter with a computer connection-- if such a thing exists.

Best thing is to chuck the tank heater and get an instant use heater that only runs when you turn the water on. If you're using hot water mainly for dishwashing and short showers-- that could be the biggest saving. I've seen the units for as little as 600 bucks at Home Despot. Plus installation, naturally, but I've put in electric tank heaters, and one of these shouldn't be any trickier.

[Inchworm]

7. Added info KWH usage last 6 months

1151 December's bill

Kicked brother out

855 January's bill

Started turning Stereo/Home entertainment/etc systems off at the power strip

572 February's bill

Cold as all hell. Furnace used a lot.

633 March's bill

483 April's bill

Turned off water heater for 10 days.

432 May's bill

I'll beat 'em yet!

:rofl:

[One_Life_To_Give]

10. By definition it would have to take less energy

if you turned it off when not in use. Heat loss, which must be made up by the elements, when no water is flowing is essentially the 0temperature difference between the water and external ambient multiplied by a constant specific to your model/size of heater. Since the water temperature cannot increase with the elements off the net flow of heat from the water can never be more than it would be if the elements were able to run.

Just how much you can save will vary by model, temperature settings etc. But you can't take more electricity to turn the water heater opff for some period and then let it re-heat for use.

[Inchworm]

12. Nice explanation

Even I understood, I think.

The only way the water could lose heat making it worse than your model would be to run cold water into the HW Heater. So, by sense, if I never open a hot water valve in the house while HW Heater is off.. it WILL use less energy overall.

Right? :P

:yourock:

[One_Life_To_Give]

16. Thanks for the compliment

It's simpler to explain if the water is assumed the water stays in the tank. Although even if you were to use the hot water tap, assuming you didn't mind the cold/luke-warm water, you still would use less electricity than if you left the heater on. So there is no down side to turning the heater off other than the inconvenience factor.

So now everyone can go buy a Industrial Timer to turn off your Hot Water heater while your away.

[triguy46]

13. We installed a ground source heat pump that makes hot water...

as a result of the cooling process.

[Kali]

14. If it is well insulated you don't need to turn it off - it wouldn't be running much anyway

- that is what I would work on. Now if you aren't using it daily, turning it off might be more worthwhile.