Water Heater Blanket: BS or Good Investment?

[aglassman]

I've been looking into ways to reduce my energy costs during winter, and I keep seeing water heater blankets suggested.  I have yet to find one actual report on energy savings for this.  All the articles say: "You'll save up to 13% energy consumed by using a water heater blanket!".  I find this claim extremely hard to believe.  This may hold true for very old units, but at that point, you're probably better off just buying a new one.

I checked mine out, and the exterior of the heater is not the slightest bit warm.  I'm skeptical that wrapping it will magically improve on the manufacturer's built in insulation.

Does anyone know of any actual reports with real experimental numbers to back up the use of these blankets?

[acroy]

I purchased a roll of fiberglass insulation (the pink stuff iirc for $8-10), wound it around, and held it on with duct tape as a cheap alternative. The water heater was a gas one, and the ONLY gas appliance in the house. The gas consumption dropped by about 30%. We didn't use much anyway, but it paid for itself within a few months.

While you're at it I suggest drop the heater temp to 105-110. That temp is perfect for running the hot tap 100% for showers etc, and the lower temp will reduce temperate delta between the water heater & it's environment

[aglassman]

Any idea what year your water heater was made?

Thanks for reminding me to drop the heat temp. It is currently WAY too hot for my needs.

[acroy]

I put it on a new one I installed 2006 iirc

[grantmeaname]

Michael Bluejay says "meh". Makes sense - not much heat leakage, so not much savings by minimizing it.

[Lorin]

If your HWH is in an unconditioned space (the garage), it makes sense to insulate it. If its in a conditioned space (mine is in our laundry room) or you are in a temperate climate, it probably doesn't matter much.

[theSchmett]

Mine is in the basement. I've had the same thought, but I touch it and its just... room temperature. I don't feel any heat coming out, and I seriously doubt the 50 degree temps in the basement are seeping in.

Maybe if it were in REAL unconditioned space like a garage.

[imustachemystash]

I'm not sure about the blanket, but have you considered making a rice bag?  You just make a big beanbag filled with rice and microwave it for about 3 minutes and it stays warm for a really long time.

[imustachemystash]

Doh, I just realized what I just wrote about the rice bag was way off topic.  I thought you were asking about a hot water bottle to put under your blanket to warm up your bed.  Never mind :)

[aglassman]

Haha!  I was really confused by that suggestion!  I may get a blanket since there is one on Amazon for less than ten bucks.  I have no way to measure how effective it will be though as our heat and why are both gas.

[Hamster]

Haha... At first I thought the rice bag comment was some sort of face punch - "Dude, turn off the water heater and take a cold shower you wuss, and just warm yourself up with a rice bag afterwards!"

[giggles]

My mom has an insulated water heater in her basement, and she swears her gas bill has been reduced by wrapping.  She also only turns her gas for a few hours once a week, and she claims the water stays hot enough for the week's worth of water for 2 people. 

She is wrapping my unit later this month (insulated, in a garage) so I will keep you posted on my results.

[the fixer]

My water heater is also room temperature to the touch. If you remove an access panel, under the insulation it definitely gets warmer, but it's not noticeable on the outside.

I did notice on my water heater that some of the metal piping and pressure relief valves sticking out get hot. If yours is like mine, in lieu of a blanket you could probably just insulate those with some foam pieces.

[aglassman]

I think I'm going to focus efforts on insulating pipes.  There is some insulation on the pipes, but it looks old, and shoddy.  My water also runs ice cold for a good 15 seconds before the hot water gets there, so I know it is not doing it's job well.

Maybe I'll throw a few rice bags on the ol' water heater as well =P

[_JT]

Your water running cold initially isn't the fault of your HW heater, provided it does get warm eventually. What happens is you have hot water sitting in pipes throughout your house, and the further away from the HW heater you are, the longer it takes for fresh hot water to push the old 'hot' water through those pipes. If it's been a day since you used that particular hot water faucet, the water in the pipes has cooled to ambient temps.

[theSchmett]

Good call on the pipe insulation! If you can feel the heat coming off you are losing it!

[Kaspian]

I just did the pipe insulation thing a few weeks ago when I noticed that the really long foam pipe insulation things were only $1.75 at Home Depot.  (Was there picking up a washer to fix a dripping tap.)  I live in a 1-bedroom apartment and that piece of insulation (about 3 or 4 metres long) was able to cover all the exposed hot water pipes above my tank, under the bathroom sink, and under the kitchen sink.  Not sure if it'll rake me any big savings over the long haul, but was willing to risk the $1.75.

[reginna]

The blanket helped on our old water heater but the replacement is insulated on the inside. If the heater is old it would probably help.

[livetogive]

from what I saw in my last job, it has to be pretty old or an inefficient method (like electric) to pay for itself, but there are so many variables that it's hard to say.

Generally speaking in my last job water and/or boiler upgrades and improvements yielded the least amount of savings per capital outlay.  In larger contracts I'd see ESCos combine those measures with super efficient ones like lighting; otherwise they tend not to make a project worth it.

[Chuck]

It's ten bucks. Worth a shot, I say.

Compare your next 12 gas bills to your previous 12 and see if you've got some savings. Just the experiment alone is worth ten bucks to try out :P

[dragoncar]

Don't forget to get some mittens for your doorknobs!

[StarswirlTheMustached]

http://www.iwilltry.org/b/projects/super-insulate-your-hot-water-tank/

^ this fellow takes the time to work out exactly how much insulation you'd want, for a given payback time. For him, with an electric water heater in an unconditioned space in Minnesota, it worked out to a lot more than a blanket.
(Interestingly enough, he deliberately converted the water heater to electric: its actually cheaper than the pilot-lit gas burner he had before. Electric sucks for heating, but older gas might suck more.)

[acroy]

to those who say 'it's cool to the touch' - yes, it'll feel like it, mine did too.
But the only way to verify is with a temp measurement. Using an IR gun, mine was running warmer than ambient (don't remember how much)

My gas bill did go down substantially in the previous house where the only user of gas (outside of winter) was the water heater. The $10-12 fiberglass roll paid for itself in a few months.

Insulating the pipes is an excellent idea if you have access. It'll slow the energy loss, not stop it, but it helps!

[aglassman]

I insulated all the pipes.  Whoever put the hot water heater where it currently is was a moron.  It is about as far away as possible from any sink / faucet / shower that actually uses hot water!  I think I'll try out the insulation roll for the water heater.  I just went and looked at blankets again, and the price has gone up to $18 bucks on the same one!  It's that time of year I suppose where people are scrambling to lower their heating bill.

[Greg]

Another way to save on your hot water tank heating is to turn it down.  120ºF is a recommended safe temperature anyway.  The idea is to adjust it until it's no longer necessary to add cold back to it for a shower.  As long as you don't run out, meaning the volume of the tank is sufficient for your use, this will save some money as well.

If you can, consider moving the tank closer to the high-use areas.  Like if it's an a basement and it's all open anyway.  If not it's probably not going to be easy.

[aglassman]

It may be too much of a pain to move.  It's gas, so there is the gas line, and the exhaust duct.  I may give it shot though as my dad used to be a plumber, so he'd be willing to help me out.