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### Extracting Heat From Compost Project

Posted: Mon Nov 03, 2014 2:03 pm
My son and I are looking at this as a 4th grade Science Fair project however, I don't see how a control and/or variables can be incorporated into this particular "experiment". As presented, it seems more like a demonstration than an actual experiment. Am I missing something?

http://www.sciencebuddies.org/science-f ... p035.shtml

Respectfully;
jwexler

### Re: Extracting Heat From Compost Project

Posted: Mon Nov 03, 2014 5:57 pm
Hi,

Looking at a glance at the experiment, this doesn't seem to be a typical, straight-forward experiment with a controlled variable. It seems to be about finding the waste heat energy produced by compost. So it's more of a experiment on calculating a certain value. However, this information can be useful in determining if the energy produced is enough to heat water or supply energy for a typical family. Hope that helps!

### Re: Extracting Heat From Compost Project

Posted: Wed Nov 05, 2014 8:27 am

### Re: Extracting Heat From Compost Project

Posted: Wed Nov 05, 2014 11:22 am
boydrew wrote:Hi,

Looking at a glance at the experiment, this doesn't seem to be a typical, straight-forward experiment with a controlled variable. It seems to be about finding the waste heat energy produced by compost. So it's more of a experiment on calculating a certain value. However, this information can be useful in determining if the energy produced is enough to heat water or supply energy for a typical family. Hope that helps!

We could tweak this and perhaps have a true experiment: Control could be a compost pile with two ingredients, leaves and grass. Variables could be a second pile with leaves, grass and kitchen scraps, a third pile with leaves, grass, scraps and manure.

Shouldn't be a problem to weigh/measure the individual ingredients to ensure each pile is proportionally equal. This would change the scope of the original experiment in that we would try to determine which piles (if any) create heat and if the heat energy is usable.

We have enough material that we could do two or three trials simultaneously.

Think this would fly?

### Re: Extracting Heat From Compost Project

Posted: Wed Nov 12, 2014 8:48 pm
Hello,

Yes, I think that sounds like a great idea!

### Re: Extracting Heat From Compost Project

Posted: Thu Nov 13, 2014 2:50 pm
Well, we built 6 compost piles this weekend and surprisingly, even the control pile is heating the water...that's a surprise. It is lagging behind the other piles with added varibles though, by about 5 degrees. Our day 3 temperature measurement recorded the water temp at 95 degress F.....way more than I would have thought. Heck, we might be making our own bath water in the future.

### Re: Extracting Heat From Compost Project

Posted: Fri Nov 14, 2014 12:30 pm
Well, we have discovered a "flaw" in our experiment. Our over night temp was 19 degrees F. We had to turn our piles this morning to introduce oxygen so we decided to take a morning measurement of the water temp for the heck of it. Our control piles lacked any obvious heat, the other piles were steaming like crazy and we could feel heat with our hands. The water temp in the control pile was 60 degress F while the other piles registered in at 85 degrees F. So, this has us thinking that the control pile water temp is a result of being under black plastic and receiving full sun most of the previous day. Plus, the glass water container is "insulated" with a large pile of grass and leaves. The result could very well be simply solarization. With that in mind, perhaps our control should be nothing more than a container of water under black plastic? We're gonna try it and see what happens.