Anyone familiar with this?

Mark Hunt

http://www.howardharrisbuilders.com/

Mark H

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Constantin

Is this guy for real?

Perhaps I'm just a tad jaded, but some of the claims simply don't make much sense. For example, how does a conventional electric water heater heat water twice? There are some thermodynamic issues here that I haven't resolved yet. Perhaps someone else can clue me in?

Going further down that path, a tankless electric system ought to be always more efficient than a tank-based system simply due to standby losses. Resistance-based electric heat systems are 99% efficient transforming electricity into heat, so why bother with the tank? Perhaps the cost of getting a bigger wire service, bigger fuse-box, etc. is prohibitive.

I also suppose the tank does help the recovery rate and/or stretching by acting as a thermal buffer. But it doesn't knock my socks off the way the Allcraft stainless marine water heaters do. Not only do they feature a resistance element of your choice, they also have a removable cupro-nickel HX to let your engine do the heating for you. All stainless construction, inside and out. See more comparative specs here. Should last a while.

Mark Hunt

But


does the resistance heater heat the domestic or the tank side????

If that is the case, how can this be more efficient than a standard electric water heater when you have to push the heat through a HX???

I dunno!!!

Mark H

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Matt Clina

Standby Losses

I would contend that the standby losses of this water heater would be higher than those of a conventional water heater. This water heater holds a permanent tank full of hot water at low pressure (so it won't explode!!), which in turn heats the usable water, which flows through a coil. In order to heat the usable water to the design temperature, the water in the tank must be at a higher temperature. This increases the heat loss from the tank vs. a tank at a lower temperature.

Also, the tank is always filled with "preheated water". This is not the water that goes out to the house. Wouldn't this water get kind of nasty after a while? Perhaps the water is changed periodically, which would involve dumping a full tank of very hot water.

R. Kalia

thermodynamically speaking

> how does a conventional electric water heater

> heat water twice? There are some thermodynamic

> issues here that I haven't resolved yet. Perhaps

> someone else can clue me in?


Thermodynamically speaking, it is complete nonsense.

Constantin

That was my point...

.... speaking thermodynamically, there is no reason that this system ought to be more efficient than a standard water heater with the same standby losses. In fact, as was pointed out lower down, the internal temps would have to be higher to effect heat X-fer, thus standby losses would have to be higher for a comparative volume of water in the container.

Lastly, I can show the snake-oil salesman fascinating ways in which water heaters can fail, even with the use of a HX coil like he is proposing. On my mums boat, the HX coil that allows engine coolant to heat the tank burst/corroded. Hence, the domestic water system began pressurizing the diesel engine coolant circuit, not a good thing. I don't see why the reverse couldn't happen here.

Like I said before, the big issue with these electric water heater tanks is standby losses, in the pipes and at the tank. Retrofit as much insulation as you can justify, that's about as much as you can do with them. The only other options are to go tankless or to switch to a fuel-source whose cumulative efficiency is typically higher (think indirect tank with a condensing, modulating boiler and the like for much of the USA).

And yes, I am not accounting for the folks who get electricity for next to nothing due to hydro or other federally-subsidized forms of power.

Guy_5

It rather resembles an old side-arm tankless, only this one is heated electrically instead of through boiler water.

Guy Woollard
Heat Transfer Products

Mark Hunt

I wonder


how much it costs?

We already know how much "it will save"!!!! HAHAHHAHAHA!!!

P.T. Barnum was right.

Mark H

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Aidan (UK)

Thermodynamic nonsense

“According to the Department of Energy tests, this water heater will heat 10 gallons of incoming 58° cold water to 115° hot water temperature per kilowatt of energy consumed….”


10 gallons US = 37.85 litres.

Mass of water, M = 37.85 kg

dT = (115-58) degF = (46-14.4) degC = 31.6 degC

Specific heat capacity of water, Cp = 4.2 kJ/kg degC

Energy consumed, Q = M x Cp x dT = (37.85 x 31.6 x 4.2) kJ = 5023.45 kJ = 1.4 kW hr

Energy input 1 kW, Energy output 1.4 kW.

I think it’s another perpetual motion machine.

Supply House Rick

Plastic Water Heater

Ok,

an interesting idea, tankless coil inside an electrically heated tub of
water. Need more information on the design and output of the unit but
here's what I notice:

they calculate output @115 degrees from 58 Degrees. This equates to a
57 degree rise. Most water heaters list 1st hour numbers with a 70-90
degree rise. My take on thermodynamics is that any unit can heat more
water to a lower temperature with the same input energy (btu). They
also compare their water heater which appears to have a 30 gallon tub with
a 50 gallon electric. Not a very fair comparison!

Fundamentally if you are using electric resistance heating the output
is 3.41 btu's per watt. No matter how you do it, what shape element,
placement, fins, whatever; it's always and only 3.41 btu per watt. Any
claims to heat more water with less energy using identical heat
production seem unlikely.

On the plus side; top mounted electrode is a great idea. Most failures
are do to mineral or sediment buildup at the bottom of the tank that
eventually covers the element, acts as an insulator against all that heat
absorbing water in the tank and allows the element to overheat and melt
down. Keeping the element on top will stop that (although in all
fairness so would periodic draining and flushing of the water heater).

The tank is also presumably better insulated than an electric water
heater, this will reduce standby loss and therefore electricity
consumption. Also how reliable is whatever design they are using to maintain
water in the tub? They advertise no pressure, perhaps it is pre-filled
with oil or some other heat conductive substance.

If it was identically priced it might be worthwhile. If it is much
more expensive, I'd stay away from it. We'll probably find it adorning
the shelves at HomeDepot in 6 months.

Props to you for finding this! More than just a pretty face it seems.

Rick

Constantin

Thanks Aidan!

I didn't have the time to do the heat transfer calc, though my gut feeling was that a thermodynamic law (i.e. conservation of energy) was being broken. Yet, how many consumers will be savy enough to be suspicious about claims like "it won't heat water twice like an ordinary water heater". Etc.

I still remember how "enthusiastic" the water heater industry was about side-arm water heaters when it came to writing the coming energy efficiency standards.

Constantin

Interesting!

Rick,
You noted a number of good points regarding this design, namely how the construction of the unit may be advantageous in several respects. Let me, as a mere homeowner and engineer who developed a gas water heater, make a couple of observations.

If this thing functions as I believe it does, the electrode will never need to be de-scaled. That's simply due to the fact that the water inside the water heater never changes. Therefore, no additional calcium carbonate can be deposited inside the chamber and on the heating element in particular. Where you might see scale, however, is inside the side-arm coil. Whether that is easier to de-scale than the conventional system is for others to debate.

The "no pressure" safety claims are bogus IMHO, because the side-arm coil can and will leak eventually. At that point, the city water system will pressurize the tank, followed by being contaminated with the stagnant water inside it.

A plastic tank and/or 2" of insulation are nice but not the end-all when it comes to preventing standby losses. When I look at a water/tank/insulation system made of steel the only difference is that the R-value of the steel is like 100x lower than that of plastic. Will that, however, make a real difference? I think the answer is no, considering that it's the insulation that provides the real benefit. I haven't looked at the market offerings lately, but I would be surprised if you couldn't get a 2" insulated water heater from a "regular" manufacturer.

While Aidan has proven the thermodynamic nonsense of this design, it wouldn't prevent Home Despot or others from picking it up. I hope that their buyers are intelligent enough to recognize that this product will create more heartache for them than profit. On the other hand, given HD's alleged supplier contracts, this company could be out of business in a week, bankrupted by the narrow profit margins and the bogus returns that HD allows.

hr

Clever design

I thought. Good features regarding plastic (lifetime) tank, easily repairable.

One of my suppliers has a floor model. I have some other ideas for this tank, hydronically speaking, when the price comes down

hot rodr

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Kal Row

yeah, like

if you could add an inlet and outlet for the tank - you could use it as a solar preheater tank - but the tank would have to go on the roof since it cant even handle the the pound per 2.33 ft from the roof to the boiler room, fogetaboueet

had they made the tank out of fiberglass with a cpvc liner, then we could talk about real temps and pressures

Constantin

For something more legitimate...

...have a look at the Wattsaver from Dunkirk. It's a heat pump that uses the basement air to help heat the water. As a bonus, it cools the the interior of your home.

In other words, it uses some "free" energy from inside the home. This is a legitimate way to reduce the electrical energy consumption, though the rest of the energy still has to come from somewhere.

Products like the DX ground-based heatpump system from ECR also allow for the use of "excess" heat for the water heater via the desuperheater. A better use for the heat than simply dumping it outside.

I also wonder if folks have seriously considered attaching things like refrigerators to whole-house cooling systems. A direct connection may not be practiable (different cooling points of the refrigerants and all that) but imagine how much room you could add to the interior of a fridge if you didn't have to accomodate a exterior HX (also, no more vacuuming, etc.).

Better yet, make the compressor package external, hide it in the basement, wherever, then make the kitchen quite a bit more silent. I imagine that would be pretty popular with the service techs, since they now would no longer have to pull the fridge out every time they had to service the unit. In fact, the more charitable installers may in fact make the compressor "module" easy to service by mounting it conveniently.

ScottMP

HR ?

Life time tank with plastic ??

Tell that to an Amtrol owner !

I would like to see how this company fills the medium tank and what is the meduim, water ?

Scott


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Mitch_4

The wattersaver

Is made by EMI a sister company to Dunkirk under the ECR umbrella. DUnkirk does have the ARTESIAN. an indirest tank of similar concept.

Maggie Reed

Watter$aver

The Watter$aver is actually sold under three of ECR's brand names - Dunkirk, EMI and Utica.

Maggie Reed Lutz

ECR International