Hot water heater insulating jacket: How much savings

Measuring how much a hot water heater jacket saves.
In my case, very little. But it can save more if your hot water heater is poorly insulated, the hot water heater jacket is better than this one, electricity is expensive, and the jacket is cheap.
More about the spreadsheet I used at:
woodgears.ca/ph...
Please note that the W/m2 column in my spreadsheet had a formula error in it, which resulted im my heat-loss estimate being about 20% lower. So the payback period is actually more like 5 years. Still too long. But if your electricity costs twice as much as here, your water tank is less insulated, and you get a better insulating blanket for less, the payback could be less than a year.

[@JohnEdwa]

When using an IR thermometer, you really should keep the surface emissivity (aka material/colour) relatively constant. The emissivity value for wood is ~0.9, but for the reflective insulation or the painted metal tank it could be half or even lower than that which would completely mess up the readings. The easiest way is to stick a piece of tape on the spots you want to measure on advance.

[@dougdevine27]

Great comment and suggestion!

[@matroosoft4589]

Was looking for this comment, did research on this topic for my internship. Shiny surfaces have a very low emissivity which indeed mess up your readings. If you read the manual of the IR thermometer it will be mentioned usually. Only expensive sensors which measure on a low wavelength would have the right readings on these surfaces. (edit1, looked it up: This is because the effective emissivity of a material is highest at shorter wavelengths and the accuracy of sensors with narrow spectral responses is less affected by changes in target surface emissivity.) (edit2: cheap sensor will also have correct readings if you change the emissivity setting, but then you need to now the specific emissivity of the surface) Oh and it is indeed an IR thermometer and not a laser thermometer as some people call them. The laser is only for pointing to the spot you're reading.

[@trevorlambert4226]

He never measured on the foil surface, which would have been really different. The painted surface, not as bad an error, but yes definitely a different e than wood. I always put a piece of masking tape on whatever I'm measuring, even if I suspect they are similar e values.

[@leochen4891]

Good info, and that's probably why he measured the inside.

[@graffie]

Some black vinyl electrical tape works well.

[@FrederickDunn]

I just want to say how much I enjoy your practical approach and process when evaluating anything and everything. I quote you often and send my students to your channel time and again. How to approach a problem/challenge, and how to compile the results. You are the guy! I did now know you also have this channel.

[@kympridham8267]

what a BS vid this is as you have it internal and ambient temp is not done in cold time but during day and probably in summer . cmon dude don't treat us like idiots give us relevant information if this were science you would be laughed at

[@musicbymark]

Excellent analysis Matthias oh, I did not bother replacing my jacket of insulation when I had a new water heater installed. Also people need to remember that throughout the cold season, any heat loss from their water heater is still contributing to heating the house and therefore not an entire waste.

[@kympridham8267]

what a BS vid this is as you have it internal and ambient temp is not done in cold time but during day and probably in summer . cmon dude don't treat us like idiots give us relevant information if this were science you would be laughed at

[@Rybczynski1]

After installing jacket my entire electric bill dropped around 10% per month. Savings paid for my hot water jacket cost in 1 month. Contrary to what you are calculating savings are quite substantial and well worth the cost and effort.

[@kylemoore1865]

You realize he covers this by explaining the variables like better blanket and worse insulation on the tank itself

[@woodendiode]

So this is just a small typo on the package, 6 years, not 6 months :)

[@gardnmi]

In California it's 6 hours.

[@brandonfrancey5592]

@@gardnmi But it also causes cancer.

[@mikevanin1]

@@brandonfrancey5592 and don't forget man-made global warming ...

[@christiangeiselmann]

Mike VanIn Uahaha funny.

[@briannelson605]

My guess is somebody didn't keep track of their units

[@BrianBoniMakes]

In winter that heat loss isn't really wasted as it's going into your house but in summer it will put a bit more load on your AC which still might not be noticed unless it is heating a part of your house that makes you uncomfortable.

[@kkarllwt]

Yes, but it is electric heat. If you heat the house with gas, at about 1/3 the cost of electricity, then stopping this heat loss is good. Case dependent.

[@l.merbecks8144]

I’m sorry but that is not clear at all. For example a heater placed in the basement and locked in a fireproof room (like in my home) will mainly heat up that one room only and then radiate or convect the heat into the ground ergo heat wasted / leaving the system house. However if the house is very open and air can circulate very good you are right I guess.

[@_NikkyD_]

Also depends where that room is, how well insulated the house is etc.

[@ke9tv]

@@kkarllwt I fire my water heater with gas, too. So I don't worry much about jacketing the water heater.

[@doug-cdsimontrustee6609]

The heating of your house during winter, via the water heater, is more expensive than direct heating of your house.

[@honeyforce996]

I enjoy the energy saving videos. I'd be interested in seeing you talk about windows. Not replacing them, but perhaps trying out curtains/shutters, or seasonal coverings that could be used to insulate very large windows. Hope you & your family are enjoying the new location

[@peter_smyth]

It would be interesting to test a sheet of foil (stuck to cardboard or foam) that you put against the window before shutting the curtains at night.

[@matthiasrandomstuff2221]

that would help, no doubt, but be inconvenient. Also, it makes the inside of the window get colder, and then you run into condensation.

[@lpsowns]

@@matthiasrandomstuff2221 Could try a low-emissivity film? It's a cheap alternative to replacing windows, that gives some of the benefits that more recent windows have built-in.

[@bootsowen]

I tried the heat shrink film on my windows about 5 years ago and it works well (in that the room is noticeably warmer, but I put most of this down to draught exclusion). If you use it on the inside and the room heats up, like in our kitchen the film slackens a bit and looks unsightly. I replaced the film in some of our rooms with double glazing, in that I added brand new double glazing units to the inside of the window frames without removing the original single glazing. I used some self adhesive draught excluder around the frame and then positioned the extra glass and held it in place with cleats, this was about a quarter of the cost of having full new double glazing made and fitted. it has been in about 4 years and is excellent, both for noise and heat loss reduction. My observation to anyone who asks me about my windows or other hacks is that the greatest gains are draught exclusion. Especially around doors and windows, but also between floor boards, skirtings, electrical fittings, behind fitted units, etc., etc. This is in the UK, where there is a balance between sealing a house up, and adequate ventilation to prevent mould growth from condensation forming on cold walls. The youtuber "Peter Ward" has made some excellent videos on this. Good luck with the new house Matthias!

[@andrewlyon6834]

Matthias Wandel id watch your energy videos because you’ll tell us if there actually worth it to do to save money since you do the exact calculations or just false advertisement

[@jaguar36]

Your energy usage numbers seem very low for loss on an electric hot water heater. Instead of calculating it, why not just measure the energy used overnight when no water is being used?

[@xcruell]

Was looking for a comment like this

[@aussiegruber86]

Rheem actually publish these values and its very similar to his calculations....but 100% agree....electrical measurement would be best

[@maddin95k1]

Now you have to heat your basement more.

[@rpeet687]

My basement is currently unoccupied. We got a bit of a flooding issue.

[@Don.Challenger]

Good, buy a few RC boats maybe a submarine and play at Admiral as you wait until the coming dry season. And Good luck.

[@emmettturner9452]

You wouldn’t heat the basement in the summer.

[@Don.Challenger]

You and your doggie would take refuge down there in the cool during summer heat - why should the root vegetables and canned goods be the only survivors?

[@pbgd3]

Correct. A bigger cost savings in winter would be some form of heat reclamation efforts from your gray water discharge. Consider if you could run your hot shower water into a holding tank that dumped when it hit ambient. Your shower discharge probably going out of the tub at 100 degrees hangs out in an aluminum tank till it drops to 70 and then dumps to sewer. Using good old BTU you have 30 degrees F delta by average shower of around 17.2 gallons at 8.33lbs a gallon for around 4300 btu or 1.26kwh. That's per shower down the old drain.

[@khcopter]

Thank you for making that. My brothers told me to do that to my hot water heater. Because of you I’m not doing it now!! you are the man!!

[@sarcasmo57]

Interesting video, thanks a lot. Don't forget that that when used on shiny surfaces that style of thermometer measures heat reflections. What you should do is get a little masking tape and put it directly onto the new insulation and measure it's temperature. This way you are not measuring your own body heat reflection etc, but you are getting a direct reading through the insulation.

[@JamesBiggar]

Math pays. Stay in school, kids.

[@davinderc]

Don't do cocaine!

[@FathinLuqmanTantowi]

@@davinderc sell em

[@Stevenpwalsh]

Except he did the math after he had already given them his money!

[@simoncameron4355]

@@davinderc Why can't I do cocaine and math at the same time.... I get it done so much faster!

[@Don.Challenger]

Vape the herb - it slows the mind while calculating those tricky long divisions and painful partial fractions.

[@camohawk6703]

gotta love when someone pulls out the spreadsheet. you know that they prepared.

[@AaronBishop-st2ow]

This was an exact replacement for the old one that lasted about 10 years. kzbin.infoUgkx7yWIKcrbA9KMHkGSfcgxW2lsjHT6B8Sh The top of my mitigation tube by my roofline was just a 90 elbow which allowed too much debris to fall down into the fan, eventually ruining it. Without this issue, I bet it would have kept running another 10 years. When I replaced this fan, I added an extra elbow joint so the top tube now it does a 180, which should solve that problem. The radon guys around here wanted to charge me a $300 diagnostic fee, then parts/labor (probably close to $600 total). I installed this all by myself in about an hour for the cost of the fan; it would probably be even easier/faster with two people. FYI the manufacturer's warranty greatly differs depending on whether you install it yourself (1 yr warranty) or have a licensed installer do it (10 yrs).

[@juleswebb1885]

When using that 'bubble foil' stuff (or any type of insulation), airtightness is essential for maximum benefit.. tape up every little gap. Saying that, most of it is pretty crap. I built a 'box' around my 500 litre tank with rigid PU foam ( celotex or kingspan etc in UK) and filled the spaces between it and the tank with mineral wool for good measure. The difference was amazing : )

[@kympridham8267]

what a BS vid this is as you have it internal and ambient temp is not done in cold time but during day and probably in summer . cmon dude don't treat us like idiots give us relevant information if this were science you would be laughed at

[@1956vern]

Years ago I bought the fiberglass wrap for my water heater! What I really noticed about wraps was how warm the wrap felt! 🤪 Thanks for the science lesson! When I put the wrap on we didn’t have conculators! Lol

[@gr8bkset-524]

I stuck the same reflectix material bought as car windshield shade from the dollar store in the panels of my metal garage door. The temp measured in the inside of the door was 130F on a sunny day and 90F with the reflectix installed.

[@Sho81]

Love how they up charge when the packaging has a specific purpose. When you just buy the stuff in a bulk roll it is so much cheaper. I used the same stuff running my kerosene heater in my garage (the standard tall cylinder type) by having a wooden frame built and use that as a heat deflector. One roll with yearly re-lining lasted about 10 years.

[@supersarah5673]

As someone who is new to this topic (thermodynamics? Physics?) could you please advice me which roll I should buy:) I’m going to be a mom soon and need to save money on bills. Thank you

[@DumbledoreMcCracken]

I bought Owens Corning fiberglass, and wrapped the heater with that. Then I put the whole thing in a Styrofoam box. The tank is in an unheated garage. Winter temp outside is about freezing. Then insulated garage ceiling and door. I don't care if it saves me substantial money, I just wanted to do it. Plus, the garage now feels less cold in winter and less hot in summer.

[@acegolfman3203]

Like I did. Owens Corning fiberglass then a dollar tree plastic drop cloth cover. It's a big pink bubble....but highly insulated. Hey, the water heater is ON all the time and this winter oil is sky high so we have to save all possible

[@IAmKyleBrown]

Great video. Really shows the diminishing returns of additional insulation.

[@hvheerden]

Yes! Thanks for taking the time explain it concisely. Many products and companies assume that consumers will not question their "complex physics and math".

[@Cpl.Cadaver]

The "R" value you calculated for the jacket is correct. However the jacket you installed is supposed to act as a radiant barrier which is calculated differently and performs differently. Try increasing the air gap between the tank by about 2 inches and then do the calculations. Once the radiant barrier comes into contact with the object you are trying to insulate, it becomes useless as an insulating material.

[@SuperJamster1]

He's BACK! How we save money. Our basement is 44 degrees F in the winter, it's also where we have our propane hot water heater. It's set at a lower temperature. We also have a dishwasher. We found that if you set the dishwasher to come on and finish an 1/2 hour before you shower (i.E. before work). The dishwasher uses enough hot water to have the water heater come on heat up the tank, and you always have a nice hot shower, because it's at the high end of the thermocoupler switch.

[@davelowe1977]

Those radiant barriers apparently need an air gap to reflect effectively otherwise conduction ruins the effect.

[@matthiasrandomstuff2221]

Yes, an air gap behidn them helps. The spacer strips aren't rally that effective, but I also wrapped it around the outside of the drain pipe, so where i measured it, there was a bit of gap behind it. How it's installed makes a difference.

[@MadHatter764]

Yes, I think the treatment of the insulation numbers were for a conductive barrier, whereas this is a radiant barrier...the heat loss is to the fourth power of the absolute temperature vs the absolute temperature of the surroundings, which was (273+18)^4 vs (273+14)^4...is that close to 1.125?

[@MadHatter764]

That is only 1.056...I think this radiant barrier might be much more effective in extremely cold basements where the temperature difference is much greater than 4C.

[@greggv8]

@@matthiasrandomstuff2221 Likely would've had better performance coating the metal with white Flex Seal to reduce heat flow through the metal covering. Or put a full layer of plain bubble wrap on it first. If you're leaving it on, cut holes to expose the thermostat hatches. Trapping excess heat around them can do bad things, up to making them get hot enough to come close to catching fire. ISTR a few cases of water heaters wrapped with thick fiberglass batting in the 80's (when this craze started) catching fire. The one in our house back then came >thisclose< to burning. Scorched and melting bakelite (or phenolic or whatever plastic is in them) smells horrible, like burning oranges.

[@engineclinic]

An air gap raises any r value. Static air has a r value.

[@thomasdoherty6876]

I've used old duvets before now for insulation on tanks, I'm using a 12.5 tog one now for my loft hatch to stop heat escaping from my house and it works surprisingly well

[@MrLimetto]

You want the foil to have the least possible contact to the tank in order for it not to heat up but rather reflect the heat radiation coming from the tank

[@rapunzeleh546]

ya know, what would be awesome, is a 'engineering' class for homeowners... using inclined planes, pulleys, fulcrums etc... this kind of stuff is so useful and when it's applied to something they can use, people tend to be more interested in the math part. simple stuff like why does it take less energy to PULL something than to push it. you're just the man to do such a thing

[@supersarah5673]

Yesssssss

[@MrScotttraynor]

that "kit" looks like the exact same stuff that car windhield cooler/reflector material..

[@MaxMakerChannel]

There are w lot of products that use reflective materials to insulate and I always wonder if they make any sense. Yes they are good for infrared heat loss. You can reflect sunlight and keep your car cool, but is there a lot of infrared heat coming from a boiler? I have also seen them on socks and inside of coolers. How can reflective materials on the inside of a cooler keep energy out? Or a sheet of aluminium foil on wall insulation?

[@michael-dm2bv]

@@MaxMakerChannel - they reflect radiant heat. look up emergency space blanket.

[@Conservator.]

Max Maker Yes they work well but only for radiation and only if there’s no contact with the heat source. Otherwise the heat would transferred through (heat)conductivity. There will also be convection heat transfer (heated air flow) if the package isn’t almost airtight.

[@autobotavengerfireballxl5339]

All I can say is a solar blank saved my life once and kept me warm during a winter camping experience so yes that material does work

[@logik316]

Max Maker heat produces infrared light, and infrared light definitely produces heat in objects. Metal reflects infrared light. Therefore, using aluminum foil to reflect it back towards the heater will help it retain more heat. However, I believe it only makes sense to put the foil on the outside of the insulation cover, as the tank itself is already metal and it would do little to put a layer of foil directly against it.

[@RichardTomkins]

On your water inlet and outlet lines, install a U connection, like the water trap on a sink drain. This U will stop the convection heat loss from the hot water tank into the water line columns.

[@felenov]

It is probably 6 months in the case that you have a old boiler or a boiler that is not properly insulated

[@bobd3584]

I'm renting a house in Milwaukee, the electric water heater is in the garage (not heated). We just experienced record colds -23F wind chills -55, water heater is on concrete, no legs. Tank froze solid, it's my first winter in this place, I'm going to do some math, landlord has got to pay. Great video

[@thirstbuster78]

Verybgood analysis. Another point is that energy costs are increasing quickly, which would reduce the pay back time. Helped me decide this isnt a priority to insulate. Thanks!

[@farisfayedalshebani]

I bought this water heater kzbin.infoUgkx8G49mV71sAzUl9shXyLW-r3XgHH9EVh1 for use in my bus conversion. I installed it under my kitchen sink and it is fed by a high efficiency on-demand LP water heater. It is both a backup hot water source as well as a water saving device since we have hot water on demand rather than having to wait for the gas on demand water heater to finish its ignition cycle. I decided on this water heater due to the fact that it only draws 1300watts when it's ON instead of the 1500 watts that most Water heaters this size draw. In an RV a couple hundred watts can be a big deal. With very low standby losses, I don't have to worry about excessive power consumption. When propane is not available for our gas water heater, in conjunction with our low flow shower head there is enough hot water available to shower, albeit we won't be taking "hotel showers." Also very happy with the recovery rate of this water heater. Granted, it is quite small, but it does exactly what we need it to do.

[@JoseSilveira-newhandleforYT]

I used the same material in a totally different application - a concrete ceiling that's exposed to the sun all day and getting about 42-45ºC inside, in the summer. After installing the jacket in the ceiling, I got an immediate reduction of 7-8ºC inside. It will be more effective when I add a layer of rock-wool and a drywall ceiling. You could too add a layer of rock-wool between the water heater and the jacket and get a better result.

[@frollard]

Very cool. I'm always finding infrared scanner results dubious since they (cheap ones we have) don't have an emissivity adjustment for how shiny the surfaces are. Ideally you could place a piece of low thermal insulative material in ambient and on the heater body so you are scanning the same material for both readings to nudge the numbers closer.

[@PhilippeMarseille]

Nice EcoPeak heater - your utility will like you for the 800W load instead of a bunch of peak. I though these were only available in Québec :) Couple of tips I tried that worked (using current monitoring systems) -Lifting it up from the concrete : no need to conduct heat to the basement slab -Adding a anti-convection loop : you take the output of the tank, pipe it downward (beside the tank) a good 36in then back up. Prevents the hot water from seeping into the pipes while not used by convection. Got this trick from the NovoClimat 2.0 rules in Québec.

[@essentialjudge5430]

you should just put a timer on it. and monitor its electrical draw. way more accurate

[@va3hie]

And if you set it up to suit your peak hours of use, you will save quite a bit. Ours turns off at 11pm and comes on at 530 am. Off at 9am and on at 330 pm. I noticed a difference of about 10$ the first month. No guarantee anyone else will.

[@logik316]

I made my own heater wrap using recycled old fiberglass insulation and aluminum foil. When I place my hand under the extra insulation, the surface of the water heater definitely feels hot, and the insulation itself was free, so I think it is saving me money. I also keep the heat turned down all the way, so that it’s comfortable enough for a hot shower. All my hot water heaters had an eight year warranty, but they all lasted at least twelve years as a result of keeping them at a lower temperature.

[@Cheese_1337]

What about the bacteria and things? Is that thing real?

[@williamhadfield3852]

Draining a hot water heater annually also increases its life-span. You would be amazed how much deposits build up in them. Eventually, the minerals stick to the heating element... We replaced our HWT about three years ago because the original was too small. However, it was in good shape and 14 yrs. old!

[@ThePicha14]

If you can get yourself a flir thermal camera for example, I can't wait to see what you do with it. Perhaps go around the house to check insulation, windows, floors? Amazing opportunity

[@tyrehester5550]

ThePicha14 you can rent a Flir thermal camera from some Home Depot’s. A store near me (metro Atlanta) charges $75 per day.

[@eddydutton4614]

My test, long time ago, was to touch the water heater. It was ambient temp, so I concluded didn’t need a ‘jacket’. Ha ha. Great proof video.

[@dawebferret]

HOT water heater? LOL....just say water heater....Unless it's stolen.

[@victorl.6128]

I like you, your'e a geek too. subscribed. For my tank I used polyiso at 3" thick (R-20), got it free. Used AutoCad to figure out the cut angles like the staves in a whiskey barrel except straight. Then Tuck tape holds it all together. Saves about $3 a month in standby loss. Cheers for this, kinda always figured this stuff was crap.

[@paulkolodner2445]

I looked up the emissivities of common household surfaces like paint, raw wood, and wood finishes. They are all uncertain, with variations of a few percent. A 3% emissivity uncertainty corresponds to an IR temperature uncertainty of about 2 degrees C at room temperature. Measuring the difference between the temperatures of two different surfaces increases this to about 3 degrees C. Conclusion: the temperature differences measured in this video have a probable fractional error of near 100%. You would be much better off using contact sensors.

[@larslindgren3846]

I do not think that is correct. At room temperature in a room in thermal equilibrium the emissivity does not influence the measurement since the sum of emissivity, reflectivity and transmissivity is always 1. The problem at low emissivity is that you risk measuring reflected radiation from surfaces of different temperature such as your own body.

[@paulkolodner2445]

@@larslindgren3846 Three comments: (1) Materials like paint, plaster and wood have emissivities of greater than 0.9. So the influence of photons reflected from surfaces other than what he is aiming at is small. (2) His body is warmer than the other surfaces in the space, but it fills a rather small solid angle. So he's not contributing many photons either. (3) These effects, including what you suggest, only make the measurement more imprecise.

[@guytech7310]

Your HotWater tank likely has better insulation than older tanks. Presumably this tank blanket is targeting older tanks that leak a lot more heat,

[@TooManyHobbies786]

Great Videos as always Matthias--but FYI--electric water heaters are much more prone to legionaires disease due to cold spots in the lower corners. Therefore, its usually recommended to raise the temp in the tank to 140 and have a mixer on the outflow to bring it back down to 120. Gas fired heaters don't suffer from this since the burner is at the bottom and it boils off any bacteria. If you drop any water heater to a low setting for too long though, you do risk legionaires growth. Only way to really save money on water heaters is to go tankless--but even those have their associated issues.

[@jmstew642]

Timer on @ 4am, off at 10am, on at 3 pm, off at 10pm... Works great saves 💰

[@98dizzard]

The foil bubble wrap stuff is often a lot more inexpensive if you buy it as just a normal roll rather than something tailored to the specific application. For nearly $70 I would expect you could get enough to wrap that tank 3 times and still have enough spare to buy some foil tape to seal it.

[@98dizzard]

I can only go by the price's here but they also sell it as a radiator reflection layer. Usually 20/30gbp for enough to do half my radiators along with some double sided tape. Where as a roll of similar size is around £10

[@DeweyKentM]

A very practical and simple insulating solution would be to attach plywood to the 2x4s in front of your water heater, effectively sealing it in, and filling the miniature room with sawdust.

[@dragoscoco2173]

Wait a minute what did you measure on the second run? You measured the surface temperature of the heater again? Should you not measure the surface temperature of the insulator itself? The heat loss is proportional to the radiation and convection of the insulator versus the ambient. For the heater surface when insulated it's ambient is not 13.4 it is much higher also given the reflective coating which would look like a similar temperature for itself. If measuring the insulator reflective coating is not easy with your thermal gun black out a small portion with a marker.

[@EvilED08]

I thought exactly the same! Was looking for this comment to second it.

[@webinatic216]

I was reading all these comments and no one mentioned it. Point is that there is no leakage of heat and that it bounces back instead of going out.

[@EvilED08]

@@webinatic216 some comments further down brought it up. Wandel sais it's because he can't make a reading on the jacket because it's ir reflective. My point is that you should take a measurement where you're supposed to take it, not where it's more convenient to take it.

[@webinatic216]

@@EvilED08 Put a piece of paper on it and then take a measurement. It's still wrong way to measure it from the inside.

[@EvilED08]

@@webinatic216 I think you and I agree. But I would suggest to put mate masking tape on and measure that. But I'm in no way an expert. Some people mentioned that whatever heat escaping the tank will heat the house making it a none-loss thing. Except for in the summers when it would make an ac work more.

[@chuckr8683]

The wrap is very similar to,or is, double bubble or single bubble insulation used in metal buildings. That runs from 25 to 30 cents per square foot USD. You could use that insulation and wrap 4 tanks for the price paid when buying it as hot water tank insulation.

[@Jinguapingi]

Your results may be skewed with the IR thermometer. What we do at work is to stick a energy meter to the plug and measure the thing at idle during some days (or hours if you can't), while still monitoring ambient temperature. Nice alternative method though ;-)

[@nelsonic74]

When I was growing up my dad had a box similar to yours but with another wall it'sthe heater set in and we filled it with loose insulation that was left over from the attic it was basically free seem to work good when we had to change the water heater a couple years later we just took the wall off swept up all the insulation put in a bag. changed the heater and poured the insulation back in

[@sir_urx]

One who thinks of saving money by turning temperature down must consider Legionella bacteria hazards. 60C water standard is not just a number!

[@achillevache3866]

just don't use it for cooking or drinking, mine is heated to only 45C and it is fine

[@sonicseaweed]

There are also hot water heaters that can be set to a lower temperature and will run a legionella bacteria cycle where it heats the tank to 65c and keeps it there for 3 hours every so often to kill off any bacteria.

[@jacktrades5]

You also can't use it for bathing or hand washing or pretty much anything.

[@MaxMakerChannel]

I heard you can get them just by taking a shower in them.

[@CyberlightFG]

The mist of the water spray is enough to get infected.

[@mikezeke7041]

You want to keep water heater at +120 degrees F to keep legionella from reproducing. It is present in pretty much all municipal water in the USA.

[@Lutzboater]

Very interesting analysis. I appreciate your discussions of these types of things, and learn something everytime.

[@nicodemus7784]

I would mention that if your cost for your heat source is more expensive, you gain more savings faster. for instance, in California it is 27 cents per kw/hr. or propane that can cost quite a bit.

[@KB-kc7ou]

Just stuff that closet with rock wool!

[@matthiasrandomstuff2221]

and that would be cheaper too!

[@bootsowen]

Preferably the extra itchy kind! I hate that stuff, every loft in Ireland and the UK is full of it!

[@juleswebb1885]

@@bootsowen yep! Horrible stuff, but cheap.

[@furtim1]

When you increase the surface area of the heater, you increase the transmission of energy (like heat sinks). I heard this as an argument against some water heater insulation. Yes, the heat loss per square meter is less, but you have increased the surface area to at least partially compensate. Seems like your idea would fall in that ball park.

[@KB-kc7ou]

@@matthiasrandomstuff2221 Also... where in your house is the water heater? Mine is electric, in the middle of my ground floor, and my house is heated electrically. The way I figure it, any heat lost from my water heater is just heating my house...less work for my baseboard heaters?

[@ML-lg4ky]

Rheem sells a 3” blanket with their tanks that works awesome. Also set the tank on 4” of ridged foam if you really want to save!

[@steveoxler9774]

Not trusting the conclusions based on surface temp readings (at this point), a more reliable way to quantify the difference would be to control the ambient temperature if possible and simply clock the cycles once things had reached equilibrium. First without the insulation and then with. You might find that it the coils are energized for 13 minutes an hour with insulation and 14 minutes without--or something like that. A little work insulating the top and the first few feet of copper coming off of it might have just as much impact.

[@sarahallenhumboldt2638]

Thank you for all of your energy, time, effort, and commitment to educating and helping all of us.

[@wfqsfg]

why would someone want to heat hot water?

[@JonathanGach]

For the radiant style insulator to accomplish anything it needs to have a 1" air gap and be completely air sealed in order to provide any convective or radiant properties.

[@dave597]

Saving is dependent on ambient temperature.

[@42lookc]

If you want to decrease the heat loss, and not pay as much, wrap regular fiberglass--or better yet: Roxul--bats in vapor barrier material, and wrap your tank with that. Your material expense will be less, and your heat retention will be greater, resulting in a shorter payback time or higher Return on Investment (ROI).

[@MauriceNL1]

THANKS! for using Metric! Love your video's!

[@sebi7794]

Metric? All I hear is inches, inches, inches :-)

[@MauriceNL1]

Well on his temperature meter at least

[@KipdoesStuff]

Metric snobs are almost as bad as beer snobs. If you can't do the math in your head then get a calculator.

[@eideticex]

Looking at the price of that stuff locally. One could buy an equivalent amount of mineral wool (kale wool, rock wool, etc) and get significantly better insulating properties.

[@engineclinic]

Mineral wool is not airtight.

[@mikeroberson1461]

Always love your videos Matthias. A few more thoughts to consider: Adding insulation to your water heater will likely void your warranty. In a predominantly heating climate like mine, heat loss on the water heater is not a complete loss as it heats the house. (assuming its inside in a conditioned space) It could also prevent regular visual inspection for things like leaks or rust. More effective cost preventative maintenance would be draining it every year or so, replacing the sacrificial rod, and checking on the heating elements (electric only). I am very energy and conscious, and I decided to not put this type of insulation on my own water heater as I didn't see the benefits.

[@jeffpotter8984]

Thanks for the info. I was thinking about getting one. I assumed it wouldn't save too much but man 6 years!

[@kyrrekar]

You have to calculate the heat you get from the water heater to the house as well. If you insulate it you loose that heat in your house. But then I live in Northern Norway and we need all the heat we can get.

[@tomsverrevikse]

if you got a heatpump it is better to use the power there than on the heater..

[@Ed19601]

When I lived in Norway I saw interesting features: windows close better a d the chimney from the heater/stove is not insulated, so you get the warmth of the pipe in yr house as well. Netherlands e.g. insulates that pipe so no one can accidentally burn himself by you touching it......losing a lot of heat out the chimney

[@kyrrekar]

@@Ed19601 I have the same. You get apx 1kw pr meter pipe

[@gregmislick1117]

in the US, under the brand name " Reflectix " you can get just the material....aluminum coated Mylar or bubble wrap style like you have there. The documentation says that you want a 3/4" air gap between the surface to be insulated and the insulation. The setup on your water heater test - per the packaging - did not appear to be 3/4" However, I agree with your conclusions 100% What about building an insulated box with a very high R values ( like a Yeti brand cooler - those are amazing) which encloses the water heater on all sides - allowing for proper air gap and any needed ventilation etc for safety and fire prevention? Where do On-Demand heaters fall in here? Empirically, my 199,000 BTU Natural Gas fired on demand heater - based on the before and after gas bills - is MUCH better than the gas fire 50 gallon tank heater which it replaced. Love these studies you do when you're not doing a project.

[@MaxMakerChannel]

Is 57C° not the perfect temperature to grow legionella bacteria?

[@markusr3259]

Citation: www.ncbi.nlm.nih.gov/pmc/articles/PMC2094925/ The optimal temperature for Legionella proliferation in water varies between 32°C and 35°C, but it can easily proliferate at temperatures of up to 45°C. Usually, there is no growth above 55°C, and a temperature of over 60°C has a bactericidal effect. Thus, the WHO recommends that water be heated and stored at 60°C (3). However, studies in Quebec have shown, even when the thermostat is set at 60°C, a high percentage (approximately 40%) of electric water heaters remain contaminated because of the lower temperature, about 30°C to 40°C at the bottom of the tank.

[@mroek]

Yes. 57 deg C is not enough to kill legionella. Recommended temperature in the heater is 70-80 degrees.

[@blenderNOOb69]

If you use the whole water at least within a few days, I think legionella have no chance to grow.

[@MaxMakerChannel]

And what is the temperature when it reaches the top of the house?

[@danielwilson5102]

Don't know what happens to your water but in the UK tap water arrives chlorinated and microbe free, so as long as you start with a clean tank and a sealed system you will be fine. I have showered using water from a tank heated to 50 degrees only twice a day (Not held at that all the time, the cost would be astronomical!) for the last 30 years and I am perfectly healthy......

[@dlee6985]

Even though my eyes started rolling into the back of my head during the calculations (because I’m stupid), I found this video informative and appreciate you making it.

[@amerispunk]

There's clearly a bit too much back & forth between the spreadsheet & the calculations. Eyes glazed over...

[@Lacertus94]

12.5 ct/kWh ?! Is that common for north america? Here in Germany we pay around 28 ct/kWh.

[@TWX1138]

Gasoline where I live in the United States is around $2.50/gallon right now for 87 octane, probably $2.80 for 91 octane. Energy prices in the USA are low, which has served to disincentivize electric cars and alternate means of generating electricity.

[@sketchin72]

I pay 6.5 ct/kWh in Canada.

[@sketchin72]

www.enmax.com/ForYourHomeSite/Pages/Rates-Easymax-Electricity-After.aspx

[@volundrfrey896]

@@TWX1138 I don't think your conclusion is accurate, energy prices in Sweden is about 8 ct/kWh even though significantly more of the energy production is renewable compared to Germany. The fuel prices are also significantly higher than the US however that hasn't had the desired affect on car purchases, albeit some effect. People are quite quick to adapt their spending's, what Europeans spend on fuel Americans spend on something else.

[@thalivenom4972]

in oz its 40 per kwh. youre lucky.

[@Cedillallidec]

I live in Canada where the heating season is from September to May. Having heat leakage from the water tank contributes to the required house heating for 75% of the year. So the net energy savings would be even less here. The opposite would be true in an area that requires air conditioning for much of the year. You would need to calculate the air cooling load that the insulation has avoided and take credit for that energy. Since it is about 3-5 times as expensive to cool something than heat it, that 6 years could be reduced to 1 -2 years very quickly.

[@timothybaker8234]

Technically it’s a cold water heater, not a hot water heater. Water heater for short..

[@matthiasrandomstuff2221]

yes, and you are pedantic. Go into home depot and ask them where they ave cold water heaters. Everyone else calls it a hot water heater. So if you want to communicate with real people, just call it a hot water heater.

[@AzureFlash]

When the cold water becomes hot, it continues heating it so it stays hot until you open a faucet, so you can also say it heats hot water. It probably spends most of its time heating hot water. But I'm on board with calling it just "water heater". (I'd call it a Dihydrogen Monoxide Enthalpy Reactor but I don't think that would catch on)

[@brentleymetcalf2037]

It's just a water heater.

[@timothybaker8234]

I do call them cold water heaters at The Home Depot, I get weird stares though.

[@brentleymetcalf2037]

And Matthias sure loves the word 'pedantic'. Uses it regularly.

[@b.b.3260]

Living in the south, our tank is in the attic, which is not insulated. So when the attic gets bellow freezing, we get a huge radiant heat loss. Loads more savings in this situation.

[@norxcontacts]

$50 shiny bubble wrap

[@matthiasrandomstuff2221]

yes, a bit much for what it is!

[@Petertronic]

Yes, foil covered bubblewrap. That stuff started appearing in the hardware stores here in the UK about 10 years ago, and I'm dubious of the claims and don't think it is a substitute for a nice thick rockwool jacket.

[@Conservator.]

The air gap is essential to get better insulation values!

[@NitroMaxOriginal]

What was the temperature of the water in the tank during your tests, was it the same??????

[@TWX1138]

Water temperature is controlled via thermostat. The heating elements run up to the temperature set on the thermostat and then shut off. So basically the water should be at the same temperature, with the heating elements running less.

[@briand.1694]

If you keep a regular schedule, try putting the water-heater on a timer. That way you are not heating the water during periods of non-use.

[@DearHenryA]

That stuff was just foil lined bubble wrap with a big budget for advertising.

[@juleswebb1885]

Yep, and it's known to be pretty useless!

[@Juiczey]

Proof behind the pudding. I love it. So much more interesting than someone youtuber just making assertions and expecting ppl to believe them. You have a new subscriber sir.

[@kizbo]

Those exposed nails are giving me anxiety

[@brothyr]

it's okay. his head is underneath the the bottom of the nails. Unless he jumps, he'll never hit them.

[@kizbo]

Adam Rivera Didn’t you watch the video? He stands on the desk and reaches precariously right over the nails. Very scary

[@mephInc]

@@kizbo They're nails, not the end of the world. Only hurts a little bit and you go to the doc and get a shot.

[@kizbo]

@@mephInc How about if he slips and slams his face against a nail, puncturing his eye?

[@mephInc]

@@kizbo Wow. I bet outside is terrifying to you.

[@thealanguy4547]

Man, I love smart engineering types like you. Thanks for the analysis!!!

[@__shifty]

water. heater. not "hot water heater" ya'll stop it

[@pissgoat]

i can't stop binging your videos every night till 3 am for some reason

[@emmanuelc996]

What? This insulating jacket is not homemade of wood? I'LL SUE !!!!

[@peter_smyth]

At least paint it green.

[@matthiasrandomstuff2221]

Painting it would reduce its effectiveness.

[@juleswebb1885]

@@matthiasrandomstuff2221 build a box around the tank and fill it with wood shavings/sawdust!!

[@godfreypoon5148]

Perhaps cut matching hexagonal arrays of tiny pockets in two sheets of ply, to simulate the air bubbles in the wrap?

[@GiddeonFox]

My parents' house came with a very old water heater (since replaced) that had almost no insulation whatsoever, so maybe it could pay for itself in *that* situation in 6 months... ... Except they had a solar water heater and never had to actually run the water heater itself as a result.

[@chaosmasker9858]

"hot water heater"? If you already have hot water why do you need to heat it? It's a WATER HEATER. You would think that someone making a video about it would know that. Just saying.

[@DadoRAM]

To properly measure the temperature with infrared gun you must apply black tape on the surfaces because different reflection of the materials

[@locutusofborg2880]

The reason you spend so much money heating water is that you're doing it twice. Why are you heating already hot water? Hot water heaters aren't a thing. They're just water heaters.

[@matthiasrandomstuff2221]

everybody except for pedantic pricks like you calls them hot water heaters.

[@davinderc]

@@matthiasrandomstuff2221 He's just a Borg, he'll say "Irrelevant" and keep going, but I loved your comeback!!

[@MrTarfu]

@@matthiasrandomstuff2221 or people that enjoy watching old George Carlin specials.

[@XJWill1]

@@matthiasrandomstuff2221 Nope, plenty of people call them water heaters. No reason to put "hot" in front. In fact, if you check homedepot, the categories use "water heater" without "hot" in front.

[@danieldavidson8149]

Locutus of Borg if you are so smart why does no one watch your videos? But tons of people watch and love his videos

[@QPatriot07]

You took measurements off a fairly reflective surface so you're partially measuring the temperature of the room. To get an accurate temperature with an infrared thermometer you need to measure the temperature of a surface with emmisivity close to 1 (or recalibrate the IR gun). 3M brand black electrical tape is pretty close, apply some to the surface and let the temperature stabilize.

[@videostarish]

You could use TRISO layered foil & foam insulation. it's 30mm thick, but gives an equivalent insulation of 210mm of mineral wool. (very expensive though). Alternatively you could do what I did, & make a cardboard 'former' around the tank, & squirt-in lots of expanding foam. My drying cupboard where my tank is, used to be VERY warm. But now it's pretty cool, & the water stays hot for a day or so...!

[@Scorch1510]

This doesn't concern me in any practical way whatsoever, but I heartily appreciate the solid maths anyway. Thank you very much.

[@michaelovitch]

Copper pipes full of water entering and exiting of the heater are very good heat sinks also...

[@SuperAWaC]

putting the heater in a closet with no ventilation (obviously not for gas heaters) seems more effective, since air in the closet would be an additional insulation.

[@jim0648]

I hope I didn't miss the caveat about using this insulation with a gas fired tank. No insulation on the top and other required openings. I wrapped my 40 gallon electric heater at the cottage with 2+ inches of fibre glass and a vapour barrier plastic cover and used 3 inches of blue foam on the top. I switched it off on Sunday night and on return the next Friday it was still hot enough for a long hot shower.

[@kkarllwt]

The vinyl coated insulation used to insulate metal buildings, and pole barn buildings, can be had for free. ( almost, plus your labor ) If you see one being built, stop by after the walls are up and ask for the scraps. They are paying to dispose of them. Offer the Forman a case of beer for a big pile of scraps. I have insulated a number of buildings this way. It will be tedious to remove the vinyl covering if you are insulating an attic. But, again, almost free for very good insulation.

[@Psycherz]

Got radiant heat loss but what about conductive heating of the air surrounding the unit? Reading ambient temps would have been worth doing, surrounding the unit. Also introduces complications, however, such as general ambient temperature and humidity that you'd need to factor in. Not impossible though. I imagine this would be just as large if not a larger factor than radiation loss, which you measured, hopefully making the numbers better. I like the other bits of advise though, especially at the end. Never thought to reduce low coil temp for people that have oversized units.

[@TacoMaster3211]

My grandfather used to keep his hot water tank on a timer. It would start warming about 2 or 3 hours before he would wake up, that way it's ready for his morning shower, and for him to do the dishes after breakfast. He then had it turn off, but had some fiberglass insulation around it, so it would stay warm for a while after. He lived alone, so he didn't use that much hot water in the first place, so he had one of the small halfsized tanks.

[@matthiasrandomstuff2221]

a timer makes a lot of sense if you have time of use metering

[@TacoMaster3211]

@@matthiasrandomstuff2221 I'm not sure if he had time of use metering, but he was in northern Ontario, where hydro is pretty expensive to being with, so that's more so why he had the timer. No point paying to heat the water when you don't need it.

[@Yonatan24]

@@matthiasrandomstuff2221 A good idea, but we've gone through I think 4 or 5 timers in the past 5 years (220v heater). Chinese junk!