<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><p class="MsoNormal">I have a friend who has a pond on his land in Southern Illinois. He wants to use the pond as a component of a water-source heat-pump cooling system. He’s looking for a formula (or several?) he can use to calculate the length of collector/coolant tubing he should install in the pond to provide a given amount of air cooling (he understands the need for pump, heat exchanger, fan, duct, etc).<o:p></o:p></p><p class="MsoNormal">Do you know of such formulas, or where to find them?<o:p></o:p></p><p class="MsoNormal">Other details, in case they’re relevant:<o:p></o:p></p><p class="MsoListParagraphCxSpFirst" style="text-indent: -0.25in; "><span style="font-family: Symbol; ">·<span style="font-size: 7pt; font-family: 'Times New Roman'; "> <span class="Apple-tab-span" style="white-space: pre; "> </span> <span class="Apple-tab-span" style="white-space: pre; "> </span> - </span></span>He’s looking to cool a 768 cu ft studio adjacent to the pond<o:p></o:p></p><p class="MsoListParagraphCxSpMiddle" style="text-indent: -0.25in; "><span style="font-family: Symbol; ">·<span style="font-size: 7pt; font-family: 'Times New Roman'; "> <span class="Apple-tab-span" style="white-space: pre; "> </span> - </span></span>He may use cheap vodka as an affordable coolant (happy turtles if there’s a leak, says he)<o:p></o:p></p><p class="MsoListParagraphCxSpMiddle" style="text-indent: -0.25in; "><span style="font-family: Symbol; ">·<span style="font-size: 7pt; font-family: 'Times New Roman'; "> <span class="Apple-tab-span" style="white-space: pre; "> </span>- </span></span>Electricity will be PV (“so probably a fatter pipe and lower power pump”)<o:p></o:p></p><p class="MsoListParagraphCxSpMiddle" style="text-indent: -0.25in; "><span style="font-family: Symbol; ">·<span style="font-size: 7pt; font-family: 'Times New Roman'; "> <span class="Apple-tab-span" style="white-space: pre; "> </span>- </span></span>He’s considering using a salvaged air conditioner heat-exchanger<o:p></o:p></p><p class="MsoListParagraphCxSpLast" style="margin-bottom: 0.0001pt; text-indent: -0.25in; "><span style="font-family: Symbol; ">·<span style="font-size: 7pt; font-family: 'Times New Roman'; "> <span class="Apple-tab-span" style="white-space: pre; "> </span>- </span></span>In his words, “If I have water temp at about 55 degrees, how to calculate BTUs from a loop of X feet in a D diameter pipe of L length.</p><div><br></div><div>Thanks for any help you can offer!</div><div><br></div><div apple-content-edited="true"><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; font-size: 12px; border-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><div><br class="Apple-interchange-newline">Carol Venolia, Architect and Domestic Nature Goddess</div><div><b>Come Home to Nature</b> (<a href="http://www.comehometonature.com/">www.comehometonature.com</a>, <a href="http://www.facebook.com/comehometonature">www.facebook.com/comehometonature</a>)</div><div><br></div><div>Author, <b><i>Get Back to Nature without Leaving Home</i> </b>(<a href="http://www.comehometonature.com/ebook-get-back-to-nature-without-leaving-home/">http://www.comehometonature.com/ebook-get-back-to-nature-without-leaving-home/</a>)</div><div>Coauthor, <i><b>Natural Remodeling for the Not-So-Green House</b> </i>(<a href="http://www.naturalremodeling.com/">www.naturalremodeling.com</a>, <a href="http://www.facebook.com/naturalremodeling">www.facebook.com/naturalremodeling</a>)</div><div><br></div><div>PO Box 4417</div><div>Santa Rosa, CA 95402</div><div>707-538-1249</div><div><br></div></span></span></span></span></span></span></div></span></div></span></div></span></span></div></span></div></span></div></span></div></span></div></span></div></span></span></div></body></html>