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View Full Version : Water heater.... add a timer? benefits?


SMARTT
Apr 12th, 2009, 10:36 PM
Has anyone added a timer on their Water heater? do you save anything by doing this? Can a timer be useful to heatup the water tank at a given time?

let me know your thoughts?

Justin
Apr 12th, 2009, 11:07 PM
Has anyone added a timer on their Water heater? do you save anything by doing this? Can a timer be useful to heatup the water tank at a given time?

let me know your thoughts?

What happens if you need hot water at another time? Wait 30 min while it heats up?

SMARTT
Apr 13th, 2009, 10:01 AM
What happens if you need hot water at another time? Wait 30 min while it heats up?

well you need to plan it accordingly, such when you are at work, it's always off.

trixstar
Apr 13th, 2009, 10:28 AM
what if something happened at work and you needed to shower asap??

hmmmmm..:lol:

mcplar
Apr 13th, 2009, 12:28 PM
The savings of having it off will be countered by the amount of energy used to head a 40gal tank of luke warm water up!

dark169
Apr 13th, 2009, 12:29 PM
if your home is heating by electricity you'll save exactly ZERO in the winter, but if you cool your home in the summer their would be savings to be had.

Insulate your water heater and hot water lines. Insulating your hot water lines will slow the cooling in the pipes so you don't have to wait for the hot water to reach the tap, putting less once heated water down the drain.

BMWWW
Apr 13th, 2009, 12:44 PM
The savings of having it off will be countered by the amount of energy used to head a 40gal tank of luke warm water up!

I agree--though not entirely. I'm sure there will be very marginal gains, but for the loss of convenience, it'll be completely 'not-worth-the-hassle'.

+1 for insulation and those blanket things for the tank.

Mario38
Apr 13th, 2009, 01:32 PM
There is value in turning down or off the temperature of the water heater. The value is directly related to the length of time the temperature is lowered. The gains are had when the temperature in the tank goes down. Then the amount of heat loss by the water tank is reduced because the difference between the inside air temperature and the water is reduced.

But here is the problem. Because the water tank is well insulated (or should be), the water temperature does not go down a significant amount in say 6 hours. For extended periods of time though, it is definitely worth turning down the temperature. For example, I leave my water tank off while on vacation.

The other factor, as was mentioned above, is the savings are less during the winter because the loss of heat from the water heater is used to warm the house.

Another method of saving water heater costs is to reduce the temperature of the water such that one rarely has to mix hot and cold water. For example, when taking a shower, if you have to use a mixture of hot and cold water, the temperature of the hot water may be too high. One needs to take into consideration all uses of hot water though, to set the ideal temperature.

MrBurns
Apr 13th, 2009, 04:40 PM
Turn your water heater temperature down and turn it off when you go on vacation.
Otherwise leave it alone.

plymouthhater
Apr 13th, 2009, 07:09 PM
Go tankless.

Heynow999
Apr 15th, 2009, 02:39 AM
An electric water heater is what I call "North American" efficiency. You may find places in Europe that keep a 40 gallon tank warm 24/7/365, but I have been to many homes there and not a lot of people do that. It really is crazy, and I think it will be a thing of the past soon.

I have a solar water heater, and I can look at a graph of the tank temperature on the controller. My tank is a special, well insulated solar tank. I have also wrapped it with extra insulation. I have an electric element in the tank for back-up that is on a timer. When the timer goes off at night, the temperature in the tank drops surprisingly quick, but I can see that it warms back up quick as well. This says to me that there is a lot of energy wasted keeping the tank at temperature all night long.

There are some things you can do to reduce your cost. As mentioned, insulate the tank and both pipes as heat is lost through convection, conduction and radiation. Hot water can thermosyphon up the cold inlet so that should be insulated. Also as mention, turn the heat down. If you don't use a lot of water, you can turn the bottom element down even more. Who needs 40 gallons of hot water at one time?

But here is why you want to put it on a timer. In ontario there is going to be time of use metering soon. Hydro is going to be quite a bit cheaper at night so you can put it on a timer and crank it up at night and hope you make it throught the next day. My timer is pretty easy to turn on if I need to turn it on for extra heat, but I wish it were a bit more user friendly. You have to open the cover, not something I would want the kids doing.

pitz
Apr 15th, 2009, 03:44 AM
....not only that, but *nobody* in North America, it seems, recovers waste heat from the waste hot water.

Basically, all hot water sewage in a house comes from a) shower, b) dishwasher, c) clothes washer. Mainly the shower.

Pump all that water into a heat exchanger that pre-heats cold inlet water (ie: water that is to go into the water heater), and voila, you've recovered a significant amount of heat overall.

North American residential HVAC is atrocious, both residentially and commercially. Can't even begin to describe how bad and innefficient we've become.

Heynow999
Apr 15th, 2009, 03:58 AM
....not only that, but *nobody* in North America, it seems, recovers waste heat from the waste hot water.

Basically, all hot water sewage in a house comes from a) shower, b) dishwasher, c) clothes washer. Mainly the shower.

Pump all that water into a heat exchanger that pre-heats cold inlet water (ie: water that is to go into the water heater), and voila, you've recovered a significant amount of heat overall.

Exactly! I just wish I had know about it several years ago when I reno'd by basement. It is such a no brainer it should be in the building code. I am considering cutting a huge hole in the wall so I can retro fit a heat recovery pipe, but I need another project like I need a hole in my head. The price of copper has come down a lot so the pipe might be cheaper now.

brunes
Apr 15th, 2009, 07:13 AM
Putting a water heater on a timer is a foolish idea. Almost all of the energy used in a hot water heater is used to heat the cold water coming into it up to the right temp. Once it is there, it uses next to nothing to maintain it. If you had it on a timer, it would be cooling off for hours per day, at which point it would have to re-heat all that water again. You would gain nothing, and in fact I am pretty sure it would end up costing you more,

If you want more efficient hot water,then invest in an on-demand hot water system, which elimnates the hot water heater entirely. Or look into alternative choices, like solar heaters etc, as mentioned.

pitz
Apr 15th, 2009, 09:13 PM
Exactly! I just wish I had know about it several years ago when I reno'd by basement. It is such a no brainer it should be in the building code. I am considering cutting a huge hole in the wall so I can retro fit a heat recovery pipe, but I need another project like I need a hole in my head. The price of copper has come down a lot so the pipe might be cheaper now.

Yeah...but do you know of any heat exchangers that are relatively easy to install, won't clog up, have a fairly good heat transfer coefficient, and are, ummm, fairly self-maintaining?

Having to spend a Saturday afternoon in the basement cleaning a heat exchanger clogged with hair, skin particles, and soap doesn't appeal to me.... but are there any good designs to date that avoid these problems? Self-cleaning heat exchangers?

Heynow999
Apr 16th, 2009, 06:26 AM
http://www.retherm.com/HowItWorks.htm

noting to clog. It works just like a normal piece of sewer pipe.

Heynow999
Apr 16th, 2009, 06:35 AM
http://waterheatertimer.org/4ShowNumber.html