PLUMBING e Continued from p 23


each of the 39 fixed-speed pumps. These devices are used to set the needed flow rate, but the AUTOADAPT function in the revised configuration made them unnecessary. • Reduced need for testing and balancing. The experts who typically set the circuit setters usually work for an independent testing and


| VARIABLE-SPEED CIRCULATION |


balancing company hired by the installing contractor. As the designation implies, the T and B mission is to set the various installed components in a heating system in line with the design parameters of the project before it is formally commissioned. Balancing the flow rates of the


various zones in a radiant or snowmelt system is “one of the trickier aspects of small and mid- sized commercial projects like the Gallatin Car Wash project,” says McMullen. “Engineering parameters don’t always coincide with the actual conditions a system must run under. The boiler and piping specifications may call for 50 gpm, but conditions may dictate only 10 or 25 gpm.” Balancing a system to handle flow


Pat and Erik put the final touches on the mechanical room: McMullen first encountered ECM variable-speed technology in 2008, as one of roughly 200 beta-testers of the Alpha circulator in the United States.


24


rates that vary from 10 to 50 gpm requires additional components, such as secondary balance valves and pressure differential bypasses. These sophisticated technical components


“tend not to stay in balance over the life of a system,” McMullen contends, “and must be regularly tweaked and adjusted. It’s a moving target. This is where the AUTOADAPT function is so valuable for a builder owner as well as for an installer like myself. Once you install this type of pump and set it to the AUTOADAPT function, it will automatically adjust its speed after a short period. Put the pump on AA and walk away; it makes the installer’s job so much easier.” Because of this automatically self-


adjusting, variable-speed technology, PJ’s did not use its customary T and B partner quite so extensively at Gallatin. “Our testing and balancing guy is very skilled, but we can foresee the day when testing and balancing will not be necessary on the wet side of a radiant and snowmelt system. The intelligence of the variable-speed pump will take care of the balancing for us.” It is also interesting to note that


the versatile ECM circulators also offer fixed-speed options that McMullen and his team find highly practical. “That feature is handy for air elimination and purging a heating system. After an initial purge with a glycol-ionized water solution, for which we do not use the circulators, we just ramp the circulator up to Constant Speed 2 to get the air out more quickly, removing the micro- bubbles from the glycol solution. Once the system is ready to go ‘live,’ we switch to AUTOADAPT.”


True believer The ultimate impact of the switch


to variable-speed pumping technology at Gallatin Field will not be fully understood until the performance results through the 2010 – 2011 winter are recorded and analyzed. But the owner of PJ’s Plumbing & Heating is fully confident his recommendations to the general contractor were on the mark. McMullen first encountered —


and became a true believer in — ECM variable-speed technology in 2008, as one of roughly 200 beta- testers of the Alpha circulator in the United States. He replaced two 85- watt circulators in his own home just before the 2008 – 2009 heating season. Over the next two years, the replacement pair operated consistently at an average of nine watts, he reports, even on days when the mercury nosedived seriously below 0°F, as it will often do during Montana’s brutal winters. “Over the past 35 years, PJ’s has installed up to 1,000 hydronic and


e Circle 29 on reader reply card e Continued on p 26


phc january 2011 www.phcnews.com


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88