Getting Into Hot Water

by Dan Schafer

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About a year ago our Sears gas water heater died. It had survived being shipped across the Pacific to Taiwan about 15 years before that and being installed by an amateur on a rainy mountain in the suburbs of Taipei. Then when we moved to Thailand it had a damp journey in a leaky container to Bangkok and overland to Lamphun. There the same amateur bravely installed it in a rented house. When we built our new house a few years later, one thing we didn't buy new was a gas water heater. In fact we couldn't find one in Thailand to buy. And since we had no love for increasing our electricity bill for hot water, our battered but still tight Sears tank got moved again. But all good things must end. And though, I guess, digging in the right Sears warehouse might have yielded the parts we needed, our first efforts turned up what looked to be the real thing but were in fact the right part for the wrong device.

So what does that have to do with the world's crying need for a solution to its energy problems? Originally this article was scheduled to be about solar energy. Indeed it almost was, as was also our new hot water heater almost a solar powered one. But as Robert Frost puts it, "Way leads on to way." And our search for a new hot water heater kept leading on. First it led from concluding that Thailand still didn't believe in gas hot water heaters -- at least not the kind that can let three Americans all take showers at once while the dishwasher is also using its share -- to a chance phone call to a Bangkok yellow pages number. The strange thing about the phone call was that it then led to a Bangkok businessman who seemed to speak American English better than he spoke Thai.

In fact Michael had solar water heaters, which we hadn't thought we were looking for. But having found someone who had them, we acknowledged that it made good sense in a country with as much sunshine as Thailand. In fact we began to get quite enthused about making use of the sun instead of just protecting ourselves against it. But in the course of studying the literature Michael sent us, we found he had a second solution to hot water that also did not consume electricity or gas. But beyond that this second solution promised to save us money on our air conditioning electric bill. {short description of image}

This solution uses water to cool the air conditioner and at the same time heats the water. It wasn't essentially a revolutionary idea. Large commercial air conditioners have long used water cooling towers to help the air conditioner compressor get rid of the heat it is pumping out of the cooled building. And, similarly, heat exchange systems are no new phenomenon. But putting the two together into a practically affordable and uncomplicated system was certainly new to us.

Basically the system we installed takes heat collected by the air conditioning coolant, and passes that heat to the tap water of our house by means of the air conditioning compressor and a heat exchanger. Normally smaller air conditioners like ours attempt to dissipate their waste heat into the outside air by means of a condenser. A condenser works much like the radiator coil of a car. It similarly has a fan blowing air through it to speed the cooling. But you don't need a degree in physics to guess that the hotter the weather outside the less efficient such a system becomes. But our refrigerant-water heat exchange system helps that cooling process by a more positive disposing of that heat. The hot coolant and the relatively cooler tap water pass one another in opposite directions through the adjacent copper tubes of the heat exchanger. In the process it makes the compressor's job and the condenser's job easier meaning that they end up using less electricity to achieve the same cooling job in the building.

Now many of us are not very technically minded and we might think that does not sound like a promising way to get very hot water. But the surprise is we have had to start using hot water for all kinds of things like washing clothes and washing our bikes where we used to frugally only use cold. In fact there have been times we have had water in the storage tank hotter than 80 degrees C (176 degrees F).

Even if you are technically minded you might guess the electrical saving is pretty insignificant. But, ironically, if we can use enough FREE hot water, the savings in electricity on cooling alone can be 30 _ 40%. In Thailand, where a relatively high percentage of both industrial and domestic electrical consumption is related to air conditioning, 30% - 40% savings is very significant. Certainly in our factory, depending on the season, up to half our electrical consumption comes from making the atmosphere comfortable for our workers.

Our free hot water not only means savings in electrical consumption. Of course now we use no gas for water heating. That means from our little corner of the fossil fuel consuming world both our own and some of our share of the local power company's consumption is down and our contribution to carbon dioxide in the atmosphere has become less, too.

I enjoy researching and discovering new technology breakthroughs in regard to the development of renewable energy. It is quite exciting to see how technology can start to make possible some of the ideas we only dreamed about before. But practically speaking I know that the great majority of us are part of what I have called above, the fossil fuel consuming world. Even if we like the idea of switching to renewable energy sources, we have enough other problems in our lives to keep us from getting much further than just talking about what could be done. But there, I believe, lies the beauty of ideas like the one we are discussing today. It is a step that is not too expensive and not too far out, perhaps into something that could cause us more headaches than we already have. But it is a step that helps to solve some of the problems we are facing day to day as well as moving in a good direction in regard to conserving this world's resources.

I would like to discuss some more ideas like this in future articles.

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