Company Develops Microwave-powered Water Heater

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."

Comments

Re:microwaves more than 100% efficient?

[G-funk]

That's if you just count kw->BTUs, but that's not what they're talking about. They're talking about a complete system. You can't heat water efficiently for your showers with coils because they take time to heat up, they waste energy when they're cooling down and you're not in the shower, and because it just takes so darn long to do it without a huge amount of coil (which would use more energy in heatup / cooldown), you have to store it hot. And storing something hot is just about the least effecient thing you can do in this universe, and as such "the system" tends to be quite inefficient. With a magnetron it's not seeping heat into the air while it cools down (well not within an order of magnitude the same amount), it's more or less instant-on. So you're not leaking your power into the air in your heater cupboard and the frame of your house. The only thing newsworthy about this though is that it's taken so long for someone to think up and implement a viable microwave solution.

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:that's more like it

[keraneuology]

In a former life I lived in Costa Rica for a couple of years. In all that time I saw exactly -two- hot water heaters. (Out near Puntarenas and down in San Isidro the water simply comes out out of the plumbing warm 24/7 without any human intervention.) To get a hot water one had an electric gizmo that threaded onto the end of the horizontal pipe sticking out of the wall in the shower (unless one had this electric ducha one never had a showerhead ofcaug any kind). All showers that I ever saw were constructed to include a large frankenstein-style knife switch in the shower stall with you mounted up in the corner, hopefully away from the expected stream of water. Wiring was one hot, one neutral.

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.

No, another example of cut and paste...

[Constantin]

This "article" is a press release being marketed as news by the Globe and Mail. Here is my letter to the editor.

Reprinting press releases and announcing them as news in your publication is a pretty sad state of affairs. Your "article" fails to analyze the technology even in a rudimentary fashion. For example, if the reporter had turned on a crticial thinking cell, perhaps he/she would have inquired how a micro-wave based tankless water heater was going to be more efficient than a resistance-based one?

You cannot get around the Physics that it takes 1 BTU to heat a pound of water by 1 degree Farenheit. Tankless electric water heaters have existed for years and are 99.9% efficient at turning electrical energy into heat... just like this microwave technology. So no efficiency gain there, and never mind answering the question where the electrical power comes from in the first place and the conversion efficiency at that end.

How about comparing the efficiency and energy consumption of a tankless electric water heater (of any kind) to a tank-based water heater that uses a heat pump, a desuperator from a geothermal heating system, or perhaps even an indirect water heater fired with a condensing gas boiler? That probably never occured to your reporter because he/she was under orders to secure advertising from Pulsar Advanced Technologies.

Yet, heat pump water heaters have been shown to consume a lot less net energy than their electric competition because they harvest "free" energy from the basement or the ground, even if you account for standby losses. Every kWh put into such a heater produces several kWh of heat. See this press release at ORNL for more information.

And, lest we forget, even regular gas fired water heaters achieve a higher thermal gain per net unit energy put in at the front end than any electric unit... as a typical energy plant is 35% efficient. Most of the energy going into that process escapes as waste heat, and I'm not sure that being dependent on the electrical utilities is any more beneficial than relying on the gas utilities.

Please do better than this in the future.