Waist more Energy Water tank temp set to High? Natural gas.

[lbbss]

Just curious if there have been any studies or experiments on energy used by a water tank set to high, compared to medium. I am just trying to get a feel, if its worth keeping it at medium, to save on the heating bill. If it's a matter of $50 more per year in heating, that is not a big deal. I know that no one can tell me a dollar about, for our place of living (Ontario Canada), but maybe a percent savings would be useful information.

Insulating the tank, I doubt would help much. It already has insulation inside, and it does not even feel warm to the touch of my hand. Thanks.

p.s. we have Natural gas heated.

[Edwin Pawlowski]

There are a couple of factors to consider. First, you have to realize heat is always moving to a cooler place. The greater the temperature differential, the faster it moves so increasing the temperature will move the heat more.

Next, is it really waste? If the water heater is in the garage or outdoor shed, the heat may be wasted. Since the heater is in your house, as long as you are heating the house anyway, no heat is wasted. It is just one source that adds heat, right along with your furnace, cooking range, light bulbs, etc. OTOH, in the summer if you are paying to cool the house, it is a waste.

Next consideration is personal comfort and how you use the water. Some codes have a maximum temperature so as to prevent scalding. This is especially helpful with young children or the elderly but you can also put anti-scald devices in the shower. Keeping the water hotter means you blend in less taking a shower so more is save for the next person or three behind you. Dishwashers tend to work better with hotter water also and most have boosters for that reason.

I can't give a good guess at cost differences, but I keep mine where I like the temperature to be.

[Jay Stootzmann]

Yes you'll save though it will be less than if your take is a a high efficiency [at least 2" insulated walls].

I don't remember the exact % but in my own case with a 40 gal high efficiency tank it was worth it to put it on a lower temp setting. [I live in central Illinois]

All of my home hot water pipes are also insulated.

[ransley]

Of course its a WASTE, 20% goes up the flue , or chimney, Research " Energy Factor" Tanks waste about 20% up the flue, tankless dont....

[Joseph Meehan]

To add a little to what Ed said. First during the cooling season that extra heat entering your home is not only a waste from the point of burring extra fuel, but it also has to be removed, so you are going to pay twice for having the heater turn up. Second, you are also shortening the life of the water heater.

I would certainly consider the point of safety. You really don't want that water hotter than it needs to be. With one exception having the temperature turned down is a total win. That one is the possibility of capacity when you are using more hot water than can be heated with your heater over a short time.

The decision would be based on why you might want the temperature higher and likely a larger higher efficient water heater would save you money and provide all the hot water you want.

[trader4]

I agree, that's the main issue. Dishwashers need about 130. Beyond that, the only advantage I see is that once it's mixed down to desired temp at faucet, you get a larger reserve of hot water out of the same size tank. If you're talking about a 20-30 deg temp diff, I would think for a typical gas WH, the $50 a year guestimate of cost savings might be in the ball park. Whatever the diff, it would be less with an electric, because you don't have the loss up the center flue.

[Mark]

as someone else said, most of the waste heat in a gas heater is up the flue so yes it saves to turn it down.

also it saves becasue the tank will LAST LONGER.

I set mine heater down as low as I could where I need to set the shower valve to full hot to still get a good hot shower...

Mark

[hallerb]

please provide a link to 20% up the flue.

[Bill]

Actually $50 *is* a big deal! When saving money, it is the little things what add up to big savings over the period of a year.

Energy is especially this way. There is not usually any one thing you can do to save a lot money, but a lot of little things, which when done, will add up to a big savings.

The thing with a water heater is showers/baths. When there is hot water, less water from the water heater is used and more cold water is mixed in with the shower water. This leaves some hot water for the next person to take a shower. If the water was set to warm, you might adjust the valves to only "hot water" and no cold water, draining the water heater of all of its warm water. Then next person gets cold water!

So experiment and see how low you can go so everyone in the house can still get a warm shower. It takes time to heat up water.

Then beyond that, use less hot water. Do dishes by hand, wash clothes in cold water, get a valve on the shower to stop the water flow while you are soaping up, etc.

Also work on saving energy in your home. Add more insulation, get new Energy Star appliances, seal air leaks, etc. Tons of energy saving tips here...

[Cindy Hamilton]

Sorry, I'd use up more hot water doing dishes by hand than by using the dishwasher. Trust me on this one; I've done dishes both ways.

Cindy Hamilton

[trader4]

Yes, I agree and I think most people would use more water hand washing compared to recent vintage dishwashers. You could argue that if you were real careful about trying to save water by hand washing them, it would use less. But for the typical person doing them in a typical fashion, I bet they use more water than the dishwasher