Running the recirc pumps on an as-needed basis probably doesn't consume that much more energy since the pump power is small and you end up heating the pipes up whether you use or not use a recirc pump.  The water savings, however, is unlikely to offset the installation costs.<div>
<br clear="all">---- Steve (KZ6LSD)<br>
<br><br><div class="gmail_quote">On Tue, May 17, 2011 at 7:41 AM, natural building <span dir="ltr"><<a href="mailto:naturalbuilding@shaw.ca">naturalbuilding@shaw.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div style="word-wrap:break-word">Pablo's calculations do not seem to include any insulation on the hot-water supply lines, nor do they account for recirc pumps that have timers and aquastats which are available in any reasonable $200 model (Grundfos for instance). Set up properly, this means that the pump is not circulating water during the night or at low-use times of the day which would dramatically reduce heat-loss. He also implies that the pipes are located in un-conditioned space at an average of 52 degrees F. I would suggest this is unrealistic.<div>
<br></div><div><div><div>That being said, his underlying argument that they use more energy than they save in water is probably true. But not nearly as extreme as he makes out IMHO.</div><div><br></div><div>Regards,<br><div>

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<div><div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;color:rgb(255, 160, 18)"><div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;color:rgb(99, 10, 255)"><span style="font-size:18px">Steve Satow</span></div>
<div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;color:rgb(99, 10, 255)"><br></div><div style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;color:rgb(99, 10, 255)"><a href="http://www.naturalbuildingsite.net" target="_blank">www.naturalbuildingsite.net</a></div>
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<br><div><div>On 2011-05-17, at 5:45 AM, Steven Tjiang wrote:</div><br><blockquote type="cite">Recirc pumps saves water but are an energy waste if run continuously.  Ours has a button that you press manually 30 seconds or so before you use your faucet, and goes off when the hot water reaches the faucet.  Still I doubt the energy savings will offset the installation cost in any realistic amount of time.<div>

<br clear="all">---- Steve (KZ6LSD)<br>
<br><br><div class="gmail_quote">On Tue, May 17, 2011 at 5:41 AM, Stephen Collette <span dir="ltr"><<a href="mailto:stephen@yourhealthyhouse.ca" target="_blank">stephen@yourhealthyhouse.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">

<div style="word-wrap:break-word"><div style="font-family:Helvetica;font-size:12px;color:black;text-align:left">Here is a link (hopefully it's not scrubbed) on hot water recirculating pumps. Seems according to Pablo, they do not add up. I have one and unplugged mine as I thought (not verified, but eyeballing my electricity bill and guesstimating) that it was costing too much to run. I would be curious about thoughts on this idea from others, as I know we have had discussions in the past on these units.</div>

<div style="font-family:Helvetica;font-size:12px;color:black;text-align:left"><br></div><a href="http://www.treehugger.com/files/2011/05/ask-pablo-hot-water-recirculation-pump.php" target="_blank">http://www.treehugger.com/files/2011/05/ask-pablo-hot-water-recirculation-pump.php</a><div style="font-family:Helvetica;font-size:12px;color:black;text-align:left">

<br></div>If the link is scrubbed, please go to treehugger . com and search ask pablo - hot water recirculating pumps, and you should find it hopefully. or drop this on the end of it. /<a href="http://www.treehugger.com/files/2011/05/ask-pablo-hot-water-recirculation-pump.php" target="_blank">files/2011/05/ask-pablo-hot-water-recirculation-pump.php</a><div>

<br></div><div>Cheers</div><div><br></div><div>Stephen<br><font color="#888888"><br><div>
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Stephen Collette BBEC, LEED AP, BSSO</div><div><span><b style="font-weight:bold"><i style="font-style:italic;font-weight:bold"><span style="font-style:italic;font-weight:bold"><span style="font-style:italic;font-weight:bold"><span style="font-style:italic;font-weight:bold">Your Healthy House</span></span></span></i></b><span> </span>-<span> </span><font size="2"><span style="font-size:10px"><span style="font-size:10px"><span style="font-size:10px"><span style="font-size:10px">Indoor Environmental Testing & Building Consulting</span></span></span></span></font></span></div>

<div><a href="http://www.yourhealthyhouse.ca/" target="_blank">http://www.yourhealthyhouse.ca</a></div><div><a href="mailto:stephen@yourhealthyhouse.ca" target="_blank">stephen@yourhealthyhouse.ca</a></div><div><a href="tel:705.652.5159" value="+17056525159" target="_blank">705.652.5159</a></div>

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