Jerry Simon Posted August 20, 2008 Report Share Posted August 20, 2008 Was it here I heard water heater insulation jackets actually decrease the heater's efficiency? Scientific proof of such was available, something about a point of diminishing returns... Anyone know where I can find such proof, assuming such is true? Quote Link to comment Share on other sites More sharing options...
hausdok Posted August 20, 2008 Report Share Posted August 20, 2008 Check out this list http://www.google.com/search?hl=en&q=OR ... rt=20&sa=N Quote Link to comment Share on other sites More sharing options...
Bain Posted August 21, 2008 Report Share Posted August 21, 2008 Kurt has a couple of insightful posts on this forum that explain how insulating jackets actually decrease efficiency. I freely admit to stealing his thoughts in the recent past to make myself appear brighter. As for locating the posts, you're on your own. Quote Link to comment Share on other sites More sharing options...
Jerry Simon Posted August 21, 2008 Author Report Share Posted August 21, 2008 Originally posted by Bain Kurt has a couple of insightful posts on this forum that explain how insulating jackets actually decrease efficiency. I freely admit to stealing his thoughts in the recent past to make myself appear brighter. As for locating the posts, you're on your own. Found it...thanks...you're right, it was that Kurt nut. Insulation acts in a linear fashion fir heat transfer through the material. In math terms, H=kxT, or heat loss equals the thermal constant (U value) times the thickness of the insulation times the Temperature difference between inside and outside. More simply ââ¬â if you double the thickness of the insulation, you cut the heat loss in half. This, we pretty much all know intuitively. But itââ¬â¢s only true for flat surfaces. Thereââ¬â¢s a lot of simplification that goes on to get to that simple formula. When you start insulating cylinders, you canââ¬â¢t ignore the effect of curvature. If the insulation is thin, the effects of curvature are small, and the formula above works fine. But as the insulation gets thick, the surface area of the outside increases with the square of the thickness while the surface area of the inside stays constant. Effectively, the heat has more ââ¬Åpathwaysâ⬠Quote Link to comment Share on other sites More sharing options...
Richard Saunders Posted August 21, 2008 Report Share Posted August 21, 2008 Its written but I don't buy it. Assuming this was true, the thicker the insulation, the greater the heat loss, so adding, say 10 feet of insulation would be the same as none, do you believe that? Quote Link to comment Share on other sites More sharing options...
Jim Katen Posted August 21, 2008 Report Share Posted August 21, 2008 I don't buy it either. At one time, I proposed a simple experiment to address this theory (myth?). Start with several identical 5-gallon buckets full of hot water. Place each on an identical sheet of foam insulation board. Wrap each in a different thickness of fiberglass insulation. Place another piece of insulation board on top of each one. Monitor the temperature of each bucket over a period of several hours. I predict that if you were to plot the results, you'd see a linear relationship between insulation thickness and heat retention. Maybe this winter. Better yet, get Mythbusters on the phone . . . - Jim Katen, Oregon Quote Link to comment Share on other sites More sharing options...
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