<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">HI Drake,<div><br></div><div>Flow rate isn’t all that important for hydronic. </div><div>Most all systems just use a single pump and multiple zones. </div><div><br></div><div>I’d go with a multi speed from taco or grundfos or there are a few others if you are going AC. You’ll save yourself close to 500 $over the 26-99F</div><div><br></div><div>such as the grundfos UPS15-58 1/25 hp 3 speed should do it.</div><div><br></div><div>jay<br id="lineBreakAtBeginningOfMessage"><div><br><blockquote type="cite"><div>On Jun 18, 2025, at 2:47 PM, Drake Chamberlin via RE-wrenches <re-wrenches@lists.re-wrenches.org> wrote:</div><br class="Apple-interchange-newline"><div><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><div style="font-size: 10pt; font-family: Verdana,Geneva,sans-serif">
<div class="pre" style="margin: 0; padding: 0; font-family: monospace"><span style="font-size: 14pt; font-family: 'times new roman', times, serif;">I am considering using a Grundfos <span style="color: #595959;">Alpha1 26-99F,</span> ECM circulating pump for our off grid hydronic heating system. The pump is regulated by a 0 to 10 Volt external device measuring temperature and pressure.</span></div>
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<div class="pre" style="margin: 0; padding: 0; font-family: monospace"><span style="font-size: 14pt; font-family: 'times new roman', times, serif;">What specifically is that device, and where does it go in the system?</span></div>
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<div class="pre" style="margin: 0; padding: 0; font-family: monospace"><span style="font-size: 14pt; font-family: 'times new roman', times, serif;">Thank you,</span></div>
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<div class="pre" style="margin: 0; padding: 0; font-family: monospace"><span style="font-size: 14pt; font-family: 'times new roman', times, serif;">Drake </span></div>
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<div class="pre" style="margin: 0; padding: 0; font-family: monospace"><p><em>Drake Chamberlin</em></p><p><em>Athens Electric LLC</em></p><p><em>Ohio Electrical Contractor’s License 44810</em></p><p><em>NABCEP Certified PV Installation Professional</em></p>
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