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Company Develops Microwave-powered Water Heater
Posted by
CowboyNeal
on Fri Nov 25, 2005 02:42 AM
from the pacemakers-beware dept.
from the pacemakers-beware dept.
dponce80 writes "Pulsar Advanced Technologies has announced that, starting next week, they will launch the MK4, a microwave-powered on-demand water heater. Why is this cool? Well, until now, you had two options: electric heaters that keep a large amount of water hot at all times, or natural gas heaters that heat up water on-demand. The first is very costly and wasteful, and the second is not available to everyone, especially those in rural areas. You can't heat water up quickly enough with conventional resistance-based electric elements, as it would require huge amount of electricity. Not so with microwaves. The Vulcanus MK4 can heat water from 35 degrees Fahrenheit to 140 degrees Fahrenheit in seconds and can source multiple applications at once: showers, dishwasher, sink usages and more. The Globe and Mail has an article with a little more information."
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ooooh (Score:5, Funny)
No, another example of cut and paste... (Score:5, Interesting)
This "article" is a press release being marketed as news by the Globe and Mail. Here is my letter to the editor.
Google before you post (Score:4, Informative)
I think you ought to research your claims before posting here. Instantaneous electric water heaters have been around for years. My mother uses a SETS [sets-systems.com] instantaneous electric water heater to supply water to her entire home. Other examples of tankless electric units include remote washrooms to save on the piping, etc.
Please note that I didn't claim that electric water heaters were 99.9% efficient, I just claimed that 99.9% of the energy consumed by one would actually end up inside it. Obviously, any water heater that incorporates a buffer tank will have some standby losses. Please also note that some instantaneous water heaters have standby losses due to their use of standing gas pilots (common on older systems).
Most significantly, I urge you to research the minimum flow requirements that all instant units impose. If you have a whole house instantaneous water heater, it may be very beneficial to have a small buffer tank to cover low loads like a single faucet being cracked open enough to cause flow, but not enough to allow the water heater to fire.
What you're also missing is that the energy distribution companies are gearing up to disincentivize instantaneous gas and electric water heaters, whereever they are attached to their networks (i.e. methane and electric, LP is a different animal). That's because many distribution networks (gas or electric) cannot handle huge spikes in demand, and instantaneous water heating units do exactly that, creating predictable spikes in the morning and in the evening. How will they kill instantaneous units? Simple, peak demand metering.
Utilities and their distributors prefer the slow,steady demand that a low-recovery, buffer-tank water heater imposes on their systems. As meters get upgraded (and ours just did), the utility company not only knows how much you consume, but when you consume it. Demand metering is already standard practice in the Commercial arena (with VERY heavy-handed penalities) and it's only a matter of time before the distribution companies will try to impose the same kind of demand-control on the residential side of the business.
Jeepers (Score:5, Insightful)
BTW, the article 'summary' contains wholesale copy/pasting from the article linked to, which itself is just a press release that offers no additional data.
Has anyone considered putting together a submission etiquette guide for the editors to use when greenlighting stuff? Something that includes a dupe check, a Ron P. filter, and perhaps a 'marketfluff' detector? Such a device would come in handy for things like this, "articles" that make Popular Science read like the freakin' Encyclopedia Brittanica in comparison.
Not true! (Score:4, Informative)
Were I lived (the real world) many people had on-demand heating with conventional gear in the seventies, and still do [plumbingsupply.com].
Electric resistance-based quite common (Score:5, Informative)
In a lot of countries (like Germany where I live) on demand electric waterheaters (called continous flow heaters) are very common, especially in apartments buildings where there is no central water heating. They work well, and from the (very old) model I have in my apartment you get hot water in less than 30 seconds. Modern units can be set to a fixed water temperature and hold this even with changes in the amount of water flowing.
Also, as another poster pointed out already, those units do not use up any more energy than other technologies would to heat the same amount of water.
Marketing Crapola! (Score:5, Insightful)
If you want to heat 2-3 gallons of water per minute from say 50F to 130F using electricity you need a SERIOUS load. These on demand electric heaters often require 100 or 200 amp breakers BY THEMSELVES which most often means that in order to use them you have to upgrade your home's entire main breaker panel AND you may have to pay the utility company to give you this type of service as they typically do not have not installed equipment and lines capable of providing this amount of power to a home.
I do se a bit of an advantage in that it's possible that an on demand microwave heater, although ideally less efficient than ceramic/resistance based heaters, could provide both a size and a maintenance advantage over a conventional heater.
On-demand water heaters have been around a very long time and it seems in the last year or two they have come back in vogue again. They work OK. They can save you money. But most people can also save money with a much less substantial outlay by upgrading their old water heater to a newer model that is better insulated and more thermal efficient. There are even dual gas/electric heaters that let you change fuels to suit whatever is currently cheaper. In many areas such as the one I live in electricity is much less expensive in the winter than in the summer and gas is the opposite.
Electric heaters are 100% efficient. (Score:5, Informative)
The energy to heat water is fixed. Normal electric heaters, called "resistance-based electric elements" in this story, use 100% of the energy to make heat. They are 100% efficient.
A microwave device would waste energy in making microwaves. That wasted energy would be heat, but it might be difficult to put that heat into the water. And why spend more to get another kind of 100% efficiency?
In Brazil and New Zealand, for example, shower heaters are often 220 Volts at 25 Amps. They heat cold water instantly to shower temperature. The heating elements cost less than $10 local equivalent.
Disgusting nonsense quote from the referenced article: "The technology is designed to eliminate the deadly Legionella Pneumophila, since water will not stagnate, as it does with conventional hot water heaters."
Here is accurate information [middlebury.edu]: "Legionella
You don't get Legionaire's disease from water heaters! The high heat in water heaters kills bacteria. The linked article about Legionella says that it can live in shower heads, but that is at a cool temperature, on the outside.
The British, Great Innovators.... (Score:5, Funny)
Its stated in the article that there are two methods.
Method 1 is to heat water and store it and draw it off as needed. In the UK this is usually done with the aid of one massive tank in the roof, to store the cold water for the hot water store. And a second, to store the cold water for the working fluid, which is used to heat the water in the water store. And then of course, there is a third tank, in which the actual hot water itself is stored.
Are you with us so far?
Well, there is a variant on this method, which consists of having a mains fed hot water store. The advantage of this method is that you no longer need tanks in the roof. The disadvantage is that if this tank, which is under pressure, ever blows up, it takes the house with it. A very small chance however.
Method 2 is to heat it on the way through, either by gas fire in a heat exchanger, or by running it over a hot resistive electric heater. In this case you do not have all those hot and cold water stores in your roof space and closets.
British heating engineers have invented a third way. This interesting method has the great merit of being even more more complicated than the multiple tanks in your roof. In this method, you first circulate the working fluid through a tank of hot water, thus heating it up via a heat exchanger. But you do not bathe in this!
No, you draw cold water in a second heat exchanger through that hot water. In this way you have the benefits of both of the first two systems. You have a constant store of hot water in your closet, and two cold water storage tanks in your roof. And, you get to have hot water on demand heated up for you when needed. And as compared to the variant on method 1, you get to have mains pressure hot water, without having a pressurized tank anywhere in the house.
It is very surprising that this system has never been exported.
How 'bout checking what's written for errors? (Score:4, Informative)
This makes utterly no sense. Here in the US, and I assume in a fair number of places, we have oil or natural gas water heaters that are hot all the time, and I believe I've read (in the Whole Earth Catalog) of oil on-demand heaters. In either case, drive around outside the big cities, and you'll see house after house with 550 gal. propane tanks, like the one we had in our immobile home 19 years ago.
"Natural gas not available outside cities"?
mark
Re:Kill germs too? (Score:4, Funny)
Plus it would be emission free, and a great use of all those Soviet ICBM warhead initiators that are just sitting around, going to waste.
Just don't turn off the cold water supply....ever.
Re:Kill germs too? (Score:4, Funny)
Well duh - that's because they're made out of water!
Didn't you study Aristotle [kheper.net] in school?
Now, if you'll excuse me, I have to prepare for my job as a science teacher in Kansas.
Re:microwaves more than 100% efficient? (Score:5, Interesting)
Of course, my ex housemate ben only knows to get out of the shower when it gets cold, so I apologize for my mate using up all the world's energy when he gets one of these. On the plus side he'll eventually wash down the sink and his missus will turn it off.
Yes, I understand the OP would definitely know all this, and was just trying to make a point, but I just thought I'd elaborate^W ramble a bit with my AU$0.02
Re:microwaves more than 100% efficient? (Score:4, Insightful)
Prerequisite: I live in an area of the planet where I am heating, rather then cooling my house the majority of the year. None of this applies to anyone with an air conditioner turned on right now.
I currently heat both my house and my hot water with natural gas. Any heat that my hot water system (tank, pipes, etc inclusive) releases into the environment isn't really lost -- The "environment" into which the heat is being released is also known as my house.
The only "lost" heat is that which is carried by water out the drain and into the city's waste system.
Every bit of heat that is lost due to the inefficiency of storing the water is an equal amount of heat gained by my house, and the result is that my furnace uses that much less energy to keep my house at a comfortable 20C.
Now in my current house I'm actually using a boiler rather then a furnace. Assuming both my boiler and my hot water tank are equally efficient (which is likely fair, since both appliances do the same job, they heat water), and since they use the same energy source and hence neither is more economical, I don't think I'm losing anything by using a hot water tank rather then an on-demand method, am I?
Re:microwaves more than 100% efficient? (Score:5, Informative)
Really? So none of the electric "tankless" water heaters on this page [plumbingstore.com] actually work then?
Re:microwaves more than 100% efficient? (Score:5, Informative)
Re:Actually... (Score:5, Funny)
Re:that's more like it (Score:5, Informative)
A hot water heater's element - on demand or tanked - is submerged at all times. Therefore, almost 100% of the heat that it produces is coupled to the water - the only loss *NOT COUPLED* to the water is the heat which travels to the ends of the element where the terminals are. Electric heating of water by immersion heaters is close to 100% efficient. (We'll ignore the heat from the water which radiates through the heater; the energy loss from the hot water will occur with both conventional and microwave heaters.)
On the other hand, the magnetron, power supply transformer, rectifier diode and capacitor a microwave heater will require *all* dissipate energy, and unless they're all submerged themselves, the heat they produce will be lost.
How much heat is that? Consider, for a second, that most microwave ovens put out something on the order of 700W of RF power... and that most of their nameplates indicate they consume 1200W-1500W to do it.
So, watt for watt, will it elevate the temperature of the water more than a conventional resistance element? I can't see how, and I have more than a few University-level engineering courses in thermodynamics, chemistry and electrical engineering under my belt. It might respond faster than trying to heat up a relatively massive heating element, but... there's the magnetron.
Consider also that the magnetron is a vacuum tube which has a filament. Unless the filament is left on 24/7 (wasteful), it will take a moment to heat up before producing microwaves. A smaller and lighter filament would heat up faster, but would probably fail sooner during the repetitive on/off cycling this thing is going to experience.
Absolutely asinine. Finally the tankless water heater has one-upped itself in stupidity. Perfect for people with more money than physics knowledge.
(I come from a Northern climate where the thermostat is set to "HEAT" for 7-8 months of the year. The heat which radiates from the imperfect insulation of my water heater is simply lost *into my house* where it reduces the duty cycle of my furnace. Yet tankless water heaters are all the rage here, and I've installed dozens of them in the past year. They only make sense for compact homes in hot climates.)
Re:that's more like it (Score:5, Insightful)
Re:that's more like it (Score:5, Interesting)
As the water flows the pressure would close a switch inside the showerhead and heat the water electrically as it sprayed out. Costa Ricas tend to be shorter than Americans so these pipes are invariably mounted about 5'10" off the ground, forcing many to squat down a little bit to get under the head. An accidental brush up against the showerhead with give you a quick reminder to squat back down again. The unfortunately arrival of a moderate earthquake (fairly common) could also bring about a zap.
In one apartment the occupants (Americans, actually - Costa Ricans aren't this stupid) had spliced the wiring (120V @ 50Hz IIRC +/- 10% to allow for the ever-changing conditions on the line) with masking tape. I happened to be in there at the moment the tape burst into flames making me one of the only people in the history of the world to have been using a shower that caught fire.
Re:that's more like it (Score:4, Interesting)
If only that had been the only electric oddity I encountered.
I believe I saw circuit breakers a total of three times. I never saw a single glass fuse. What does this leave? Little pieces of aluminum that look like little wrenches. When the current gets too high they melt/vaporize. At one apartment the landlord never had spares, but would cross the two terminals in the fusebox with several turns of his solder. Who knows just how much current it would take to melt it.
Arc welding is very common - on/off switches or plugs for the welders are not. They would usually scrape off some insulation on the power line, cut off the plug on the end of the electric cord, bend the wires into a hook and set into place. To turn the machine off one swats in the general direction of the wires until they disconnect.
The electric showerheads never gave me any major problems - except for the time the americans spliced the wires with masking tape. Everybody said that they were perfectly safe (to reassume me, I suppose) but I never heard of anybody who had been electrocuted, nor did I ever meet anybody who had even heard of somebody getting zapped. Again, maybe they were just trying to reassume me.
By the way, I found a picture [belizenorth.com] of the showerhead... something that most people in this country (or many other countries) have ever seen. (I didn't read the article there, just found the picture.)
Re:that's more like it (Score:5, Insightful)
You forgot about 2 elements to the story.
1. EXCEPT for cold Northern climates where the heater is properly installed inside the house's heated area (not all of them are, some are in closets in the garage) all the heat used the majority of the time is wasted for a typical heater. Have you ever noticed how much that thing is running during the day when there is minimal demand for hot water? Net efficiency can't possibly be above 50%.
Oh, and you still pay a lot more for the 'heat' wasted by the electric hot water heater than you do for heat generated by the fuel burning furnace (whether it uses oil or natural gas). A system that doesn't have that waste heat would be more economical.
2. Where do you think the energy lost in capictors, magnetron, ect goes? I have a bright idea...let's put the heat sinks for those AGAINST THE WATER TANK COLD SIDE!!! DOH! Where else do you think the heat for a 2000 watt magnetron gets dissipated. Without knowing exactly how this implementation of a fairly obvious idea actually works, I can say that that would take some bigass fans and a huge radiator to get rid of 40% of the heat lost running a magetron this big. It must be a BIG one to heat water in these volumes this fast. It almost certainly MUST vent the excess heat into the cold water coming into the system through a radiator or something. This would have the net effect over a prolonged run-time (perhaps someone is taking a shower) of making the system very efficient. Perhaps 90% net.
At the least, this kind of system should obsolete electric hot water heaters, as well as electric assists to solar and geothermal systems.
Re:that's more like it (Score:4, Informative)
1 - ALL heat generated is put into the water, the exaust is piped via a PCV pipe ot the outside and it is cool to the touch all the time.
2 - I regularly flush the tank to get rid of sediment. Sediment is the #1 cause of hot water tank problems. it insulates the bulk of the heat that is hitting the bottom heating plate from the water. after that the chimney that goes up the center has a labrynth in it that sucks out most of the remaining heat left over.
Gas tank style water heaters are hugely more efficient than electric.
and then there are things you can do to increase efficency even further. Insulation blanket around the tank, new tanks from today do not need this as they has an insane amount of insulation around them. secondly turn the thermostat down. You do not need 200 degree water at the tap. if the tank style heater only has to maintain 120 degree water and you simply use more of it then do so. Or better yet get a timed thermostat. it cranks the temp up higher in the morning to have more hot water available for showers but reduces it for normal load during the day.
Even with the impending near 90% price increases Gas heating of ANYTHING is still much more efficient. Nobody reverts to electric unless they absolutely have to, or for convience... I.E. rural areas typically have electric water heaters because it's a PITA to find a fuel oil water heater and some think that using their propane faster is not worth it. (it is, get a propane/butane high efficency water heater and throws out that inefficent electric heater.
Now Water on demand systems are different and the electric ones are the fastest response but suck down the power like there is no tommorow to instantly heat that much water that fast. and god help you when you burn out the elements because the flow sensor was a little laggy and it overheated.. the element replacement costs nearly as much as a new heater system.
Re:that's more like it (Score:4, Insightful)
How about having your AC heat up the water?
Re:bad science = fun (Score:5, Funny)
No, no, no, you don't understand. Heat from microwaves is *more efficient heat*. It's like the difference between LEDs and incandescent light bulbs. The LEDs output almost all their energy as light, whereas the incandescent bulbs output light, but they also waste a lot of energy output generating heat.
Water heaters are just the opposite. The resistance based ones are basically just big light bulbs. They heat the water, but they also output tremendous amounts of light, which is completely wasted. (You can't see the light because you don't use transparent pipes, do you?)
The microwave water heaters only output heat (and a little bit of interference with your Wifi network). That's why they're more efficient.