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-   -   Turn down water heater during the day? (http://www.houserepairtalk.com/f58/turn-down-water-heater-during-day-5671/)

G Dot 12-03-2008 02:59 PM

Turn down water heater during the day?
 
Is this worth doing to turn it down to WARM while at work?

Then come home and turn it up? Or does this technique use more gas to heat it back up? Thanks for your help.

Glenn

woodchuck 12-03-2008 03:23 PM

With a well insulated tank and pipes it probably wouldn't come on but once or twice during that time anyway. I would say it would be a waste of time for just a few hours.

glennjanie 12-04-2008 01:53 PM

Hello Glenn:
If you pass right by the water heater on your way out and back in, it would be worth your time to turn the knob. Your gas water heater will pick up the temperature very quickly. I personally prefer the 'on demand' water heaters but they are considerably more expensive.
We have a geo-thermal heat pump that heats our water so we simply have to store it. Of course there are days the heat pump doesn't run very much and the electric water heater keeps it warm for us. I have the water heater thermostat set 10* below what the heat pump will provide so we only use the electric elements when necessary.
Glenn

GreenIsGood 02-16-2009 04:13 PM

We don't turn our's off - but we turn it down to pilot-light only setting during the day. That seems to keep it at a more economical 'heat temperature.' What I mean is, I can still wash my hands and do the dishes, but I wouldn't take a shower or bath at that setting. When we are ready to bathe, we simply turn the water heater up - giving it about 30 minutes notice. That's it - a hot shower!

Plus, my tank is covered with a thick insulated blanket - this totally saves energy/money.

Leaving it on all day seems like a waste of money to me.

racsan 03-21-2009 11:18 AM

but if its maintaing a constant 120-130 isnt that more effeicent than heating up a tankfull from complete cold? seems like if the a/c is set at a constant setting in the summer the power useage isnt bad, but if it keeps getting turned on the off based on when the house is occupied then more electricity is used. now if you were going to be away for a week or more, sure. but on a daily basis i think it would end up costing more to keep turning it down & back up.

nma 08-19-2010 04:36 PM

Quote:

Originally Posted by racsan (Post 28666)
but if its maintaing a constant 120-130 isnt that more effeicent than heating up a tankfull from complete cold? seems like if the a/c is set at a constant setting in the summer the power useage isnt bad, but if it keeps getting turned on the off based on when the house is occupied then more electricity is used. now if you were going to be away for a week or more, sure. but on a daily basis i think it would end up costing more to keep turning it down & back up.

No. Maintaining a temperature over a period of time is always going to be more expensive than just heating it up when you need it. Having said that, I'm doubtful that this is going to save a lot of energy - it will save some though.

mudmixer 08-19-2010 07:42 PM

It just makes the person feel "GREEN". but the savings would be negligible.

Spend the time and effort and just plant trees that will not be removed since they are supposedly a recycled material, except some countries frown on using wood for construction and there are better agricultural uses for the land that is precious in some large countries.

nma 08-19-2010 08:51 PM

It's possible a thermostat might be worthwhile if your water heater is really old and poorly insulated, but modern ones it really probably isn't worth it.

Nestor_Kelebay 08-20-2010 12:06 AM

Quote:

Originally Posted by racsan (Post 28666)
but if its maintaing a constant 120-130 isnt that more effeicent than heating up a tankfull from complete cold? seems like if the a/c is set at a constant setting in the summer the power useage isnt bad, but if it keeps getting turned on the off based on when the house is occupied then more electricity is used. now if you were going to be away for a week or more, sure. but on a daily basis i think it would end up costing more to keep turning it down & back up.

This can be an easy problem to trip over if you're not careful in how you analyze it.

Basically, turning down a water heater's temperature during the day works to save money for exactly the same reason that timed thermostats save money by turning down your house's temperature at night.

The reason is that adding heat to your water or your house is an investment, no different than putting in new appliances or building a deck. So, if it weren't for heat loss through the insulation, you'd pay to heat your house once in October and then enjoy comfortable indoor temperatures for the rest of the winter, just as you enjoy new appliances or a deck to have bar-b-ques on for a long time after making the investment.

Unfortunately, that's not how it works. What you're actually paying for on your gas or electricity bill is not the heat you put in, but the heat you lose. You burn gas or use electricity to replace heat lost through the insulation.

And, it stands to reason that you simply lose LESS heat by having a lower temperature differential across the insulation.

In fact, even when you're water heater is heating the water back up in the late afternoon, or your house is warming back up in the morning, you're still saving money during this re-heating period because the rate of heat loss from the water heater or house is still lower during the reheating period than it would have been had you maintained a higher temperature differential throughout the day or night.

So, even though the gas or electric meter is running, the net effect is a savings in energy because you're replacing LESS heat than you otherwise would have if you'd maintained a constant temperature.

Certainly the potential savings would be lower by turning down a water heater during the day than it would for letting a house cool down at night, but that's because there is much greater heat loss through he exterior walls and roof of a house than there is from a water heater. Still, the savings would be proportionate to the amount of heat loss.

One way to REALLY save money is to turn the thermostat in your house down, and put on a sweater. Or, wear LONG underwear; both long sleeved undershirts and long johns. You do that, and you'll be surprised at how much you can save on your heating bills.

No lie. I've had tenants ask me to come to their suite in the winter to check the thermostat and zone valve because they're cold. They're in their suite wearing nothing but shorts. No shirt, no shoes, not even socks. They'd be butt naked except for the shorts. And it's 35 degrees below zero outside. It's no wonder they feel cold. Great grampa would hang his head in shame.

Perry525 08-22-2010 01:32 PM

As you can see, there is no way to stop heat moving to cold.
You can merely slow its escape.
If you have 6 inches or more of polystyrene insulating your heater, there will still be a loss via the water in the connecting pipes.
Water is a very good conductor of heat, in fact it is 4,000 times better than dry air. You will loose heat.
However, the amount of heat lost is relevent to the temperature difference between the water temperature and the outside air or room temperature.
For a lot of the year it will be so small that you cannot measure it.


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