Author Topic: Water heater blanket?  (Read 3416 times)

Travis

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Water heater blanket?
« on: August 22, 2015, 01:37:51 PM »
The water heater in my new house is upstairs in a closet.  Would it be worth the expense to get an insulating blanket for it?  In our last house it was electric, but this one is gas.  If I get a blanket will I need to cut out portions for all these meters and pipes?
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Shinplaster

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Re: Water heater blanket?
« Reply #1 on: August 22, 2015, 04:23:30 PM »
I'm pretty sure you are never supposed to blanket a gas hot water heater.   Can't tell you all the reasons why, but assume it's a flammability thing at the very least.
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Greg

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Re: Water heater blanket?
« Reply #2 on: August 23, 2015, 08:34:04 AM »
Gas heaters are definitely ok to wrap with a blanket, you just have to be sure not to block off the intake and exhaust.

But, generally, your heater only needs a blanket if it feels warm when you touch it.  If you can't discern a warmth with your hand on the side, then a blanket isn't going to do much for you. Check the heater or the manual if you have it, you want at least R-24.

Shinplaster

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Re: Water heater blanket?
« Reply #3 on: August 23, 2015, 09:18:30 AM »
Huh - learned something here.   Our service people have always said "don't do it" when we asked about this years ago.  I just took their advice at face value, and didn't investigate further.   I guess they worry that  it wouldn't be done correctly, so "no" is their default answer.

Still not going to do ours, because our gas bill (heating, hot water, and fireplace) is only $60Can a month.  But good to know if we ever move, and things change.
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worms

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Re: Water heater blanket?
« Reply #4 on: August 23, 2015, 09:59:57 AM »
With all these warning stickers on the tank is there nothing in the small print that refers to covering it?

music lover

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Re: Water heater blanket?
« Reply #5 on: August 23, 2015, 12:23:52 PM »
Water heaters are pretty efficient...you can shut one off and still have warm water a day or two later. A 1/4" Styrofoam cup will keep coffee hot for an hour or more, and a water heater is much better insulated.

Greg

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Re: Water heater blanket?
« Reply #6 on: August 23, 2015, 12:24:47 PM »
Tips on this and other ways to save energy:
http://www.energy.gov/energysaver/articles/tips-water-heating

HipGnosis

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Re: Water heater blanket?
« Reply #7 on: August 24, 2015, 08:12:58 AM »
How old is the water heater?
The one I put in my house 3-5 yrs ago specifically says not to put a blanket on it.
Google the brand and model.

Bob W

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Re: Water heater blanket?
« Reply #8 on: August 24, 2015, 08:35:47 AM »
Set thermostat on heater to a level such than when you take a shower that you need to mix no cold water.   

Use cold water for laundry,  dishes,  etc.  (hot only for showers)

If allowed on your brand (don't block intake and outtake on gas) a cheap way to do it is to buy one R-19 roll of fiberglass insulation.  Then cut to fit and use a sticky duct tape to seal the seams.   

Gas is pretty efficient when it is turned down low.   No need to ever mix cold with hot in a shower.   

Then use a low flow shower head and use the following showering technique.

Wet up good for 1 minute ---- soap up as long as you like (I currently just soap face hands and private parts) --- let soap set and do it's magic.    Turn shower back on and rinse.

By doing this you will be using less than 3 gallons of hot water per day per person. 

Enjoy. 
Better living through math.

Travis

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Re: Water heater blanket?
« Reply #9 on: August 24, 2015, 08:56:34 AM »
Set thermostat on heater to a level such than when you take a shower that you need to mix no cold water.   

Use cold water for laundry,  dishes,  etc.  (hot only for showers)

If allowed on your brand (don't block intake and outtake on gas) a cheap way to do it is to buy one R-19 roll of fiberglass insulation.  Then cut to fit and use a sticky duct tape to seal the seams.   

Gas is pretty efficient when it is turned down low.   No need to ever mix cold with hot in a shower.   

Then use a low flow shower head and use the following showering technique.

Wet up good for 1 minute ---- soap up as long as you like (I currently just soap face hands and private parts) --- let soap set and do it's magic.    Turn shower back on and rinse.

By doing this you will be using less than 3 gallons of hot water per day per person. 

Enjoy.

Thanks for the tips everyone.  We moved in 3 weeks ago and I'm still figuring out how to optimize the place.  The house came with this flat articulated shower head that reminds me of a spatula and it takes a couple minutes for the hot water to show up.  If I replace it with a more efficient head will it take even longer for the hot water to flow or is there another way to speed that up?
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Bob W

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Re: Water heater blanket?
« Reply #10 on: August 24, 2015, 12:06:00 PM »
I'm guessing you are correct to assume that Low flow = slow flow -- so yeah,  it may take a bit longer to warm up.   Our main shower is probably 70 feet of pipe away from the water heater.   I haven't timed it, but it seems to take a couple of minutes for the hot to arrive.   I have a routine prior to the shower so it isn't a problem.

It may take you a week or more to adjust the water temp.   Start at a low medium and then every few days adjust down just a tad.  Then one day you will turn the shower full on at hot and the water will come out the perfect temp.

Mixing cold and hot is like running your heat and AC at the same time!
Better living through math.

worms

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Re: Water heater blanket?
« Reply #11 on: August 25, 2015, 12:21:15 AM »
  If I replace it with a more efficient head will it take even longer for the hot water to flow or is there another way to speed that up?
Depends on your plumbing arrangement but you might be able to run your hot tap in the bath or sink to get the cold out of the way quicker.

Mixing cold and hot is like running your heat and AC at the same time!

Except that the cold is coming at that temperature naturally with no added cost unlike your AC.  It may be that the most efficient operating temperature of your gas water heater is the same as your preferred shower temperature but boiler efficiency is related to a wider number of variables than just output water temperature.

Bob W

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Re: Water heater blanket?
« Reply #12 on: August 25, 2015, 09:04:31 AM »
  If I replace it with a more efficient head will it take even longer for the hot water to flow or is there another way to speed that up?
Depends on your plumbing arrangement but you might be able to run your hot tap in the bath or sink to get the cold out of the way quicker.

Mixing cold and hot is like running your heat and AC at the same time!

Except that the cold is coming at that temperature naturally with no added cost unlike your AC.  It may be that the most efficient operating temperature of your gas water heater is the same as your preferred shower temperature but boiler efficiency is related to a wider number of variables than just output water temperature.

That sounds very confusing?     Could you please elaborate on your theory?

I think most people would agree that setting your hot water temp to the lowest setting is energy efficient.       My analogy to heat and AC was an analogy.  My cold water is generally around 70 degrees and comes straight out of the ground at 56 degrees.  So my house has heated the cold a tad.   I can't understand the logic in wanting to heat water up using energy only to cool it down with colder water??   My back of the napkin annual energy savings by setting the tank temp low is around $100. 

Of course, if we have guests,  we set it higher so that less hot water by volume is required and then mixing makes sense.   Someone who only uses a total of 10 gallons or less of hot water per day will benefit from the lower setting. 

Another trick is to turn you hot water off when you are away from home for extended periods.   

Extra insulation + low temp setting = dollars saved. 

Better living through math.

worms

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Re: Water heater blanket?
« Reply #13 on: August 25, 2015, 01:18:46 PM »
You have already identified that the best way to manage the tank depends on expected rate of use.  But I would think there are also other factors at work including the way that different boilers handle the heating and cooling cycle at different temperatures, temperature-related variation in standby losses, thermal stratification in the tank and, in condensing systems, the temperature of return flows. 

And let's not even go to the question of timer-operated versus "always-on"!

Jack

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Re: Water heater blanket?
« Reply #14 on: August 25, 2015, 02:04:37 PM »
Be careful not to turn your water heater down too low, or else you can get Legionnaires Disease

Telecaster

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Re: Water heater blanket?
« Reply #15 on: August 30, 2015, 11:20:54 AM »
Blankets usually don't make sense, and can be surprisingly hard to install.    Running some pipe insulation on the hot side is easy peasy and cheap though.