SUN ON TAP

The Best We Know
by Frederic S. Langa

You Can Cut Hot Water Bill By Two-Thirds... 
With A Fine-Tuned Passive Solar Heater

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I 'm going to tell you a secret. I've never told this to any one before -- not even my wife -- because it's something I'm really embarrassed about.  
When I was young, I had a wildly irrational fear of the cellar. When some household chore forced me to go downstairs, I'd become utterly, insanely terrified. My heart would race, my legs would feel weak, and I'd get goose bumps. Sometimes I'd breathe so hard I'd almost black out.
To me, the cellar was a place where strange machines and nameless horrors lurked in the shadows, a place of creatures whose sole purpose was to terrorize (and maybe eat) young boys. All too often, the furnace or water heater suddenly would roar to life just as I walked by, scaring me silly. The tongues of flame visible through the air intakes seemed hungry and menacing, like some evil from the nether world. No amount of whistling in the dark or rabbit's-foot rubbing could make me feel any better.
In time, I grew out of my fears. Today, I know my cellar is inhabited only by my home's mundane mechanical systems: the furnace, the duct work, the plumbing. While it's a relief to know I'll never become an hors d'oeuvre for a hungry water heater, as an adult I've found a new and entirely rational reason for disliking the cellar's mechanical denizens.
It's not me they're after, it's my paycheck.
According to the Department of Energy, you and I now spend more than $1,100 a year on the energy it takes to run our homes. After the furnace, the single greatest energy-eater is the water heater. It costs hundreds of dollars a year to run. But you probably don't think about its operating costs because they are lumped in with other appliances that use the same fuel. As long as you get hot water when you turn the tap, everything seems to be fine. 
But everything isn't fine. Chances are, at least one out of every three dollars you now spend on water heating buys you absolutely nothing: It's simply wasted by the built-in inefficiencies of your system. To make matters worse, another third of your present water heating bill is a sort of hidden penalty for the "convenience" of using oil, gas, or electricity, because the sun easily could provide this much water heating energy for free. In other words, at least two-thirds of your present water heating expense is money down the drain.
It's this needless 66 per cent waste that our "Sun On Tap" series is aimed at. During the last year, we examined all sorts of solar and non-solar water heating systems to see which offered the best combination of performance and price. Wherever possible, we concentrated on do-it-yourself options to keep down the cost.
The full test results were reported in the last issue, but the highlights are worth repeating. No system we looked at, regardless of type, cost, or size, could beat this combination: 
First, upgrade your home's existing water heating system for maximum energy efficiency, then add a "batch" solar water heater to deliver the sun's free heat.
The batch heater itself is a masterpiece of simplicity, with no moving parts or high-tech gadgetry. Likewise, our energy-efficiency upgrading is extremely simple and very, very effective. Both jobs require only ordinary hand tools and basic construction skills, yet the combined performance rivals that of some complex solar systems costing two or three times as much. How well does it work? If you live in the South or West, where there's plenty of sun and a generally mild climate, our retrofit can save you around 18.2 million Btus per year, equivalent to about 5,333 kwh of electricity, 200 gallons of fuel oil, or 24,300 cubic feet of natural gas (multiply by your present fuel costs for a ballpark estimate of monetary savings). In colder, cloudier climates, the performance is only a little lower. Here in Pennsylvania, for example, our batch heater must be drained during the below-freezing months of December, January, and February, yet the total annual savings are still almost 14 million Btus, equivalent to roughly 4,000 kwh of electricity, or 150 gallons of fuel oil, or 18,200 cubic feet of natural gas. Of course, your local climate and the care with which you do the job will determine exactly how many millions of Btus you can save each year, but you will save. And chances are, you'll save a bundle. Right now, one of our test families is saving almost $300 a year, based on local electric water heating rates of about six cents per kwh.
As for costs, the entire job -- everything from insulating the home's existing pipes to building and installing the solar water heater -- totals just $450, not including state and local solar tax credits. (We've already deducted the 40 per cent federal credit: The full, pre-credit price is about $750.) To put this in perspective, our test retrofit will pay for itself in about a year and a half, and then will go on to generate pure profits for the rest of its 10- to 20-year life. We don't know of any solar, do- it-yourself retrofit that will give you a better return on your investment. In fact, the job is so straightforward (taking only about five comfortably paced weekends), the cost is so reasonable, and the savings so spectacular, you can hardly afford not to do it.
The next few pages contain the information you need to perform your own batch heater/efficiency retrofit. First, we'll tell you more about solar batch heaters so you'll understand how they work, and so you can choose the variation that's right for your home. Then we'll show you, step by step, how to build and install it. When you've finished, you'll have taken a giant step closer to energy independence. And who knows? Maybe you'll even start enjoying trips to the cellar. 

 


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22 RODALE'S NEW SHELTER - JULY/AUGUST 1981