tem works by a pump circulating the hot water from the water tank and to the final consumer. This ensures that the water temperature stays at an acceptable level, even at times with little or no demand at point of use. The challenge in these applications is to minimise the losses in the system. The “losses” consist of heat loss from pipes in typically unoccupied areas of the building and energy loss due to uncontrolled pumps. Energy loss when circulating the hot water typically varies between 30 to 75 per cent in high-rise domestic buildings and 50 to 90 per cent in commercial buildings and schools. There have been examples of the loss constituting from two to over 100 times the energy consumption used heating the water. It is therefore obvious that the potential for energy savings in this system is enormous. The following examples show three different approaches to solving the hot water recirculation task. Examples two and three (on page 40) show how it is possible to utilise the built-in temperature sensor in the MAGNA3.
Temperature control to reduce losses Traditionally, HWR has been handled by a recirculation pump responsible for maintaining a constant duty point, or more economically, a variable circulating flow in combination with thermostatic valves to set a minimum return temperature. With the MAGNA3 it is now also possible to do without these valves as the temperature control is performed by the MAGNA3 and its built-in temperature sensor. However, balancing valves are still needed unless decentralised MAGNA3 pumps are utilised. Benefits of the MAGNA3 in HWR: • Reduced heat losses from pipes • Easy commissioning via Grundfos GO • Reduced initial cost (no termostatic valves) With the Grundfos Go app for both iPhone and Android, it is very easy to set up the temperature control on the MAGNA3, as seen from the screenshots
For more information,
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Index to Advertisers
42
Aurora Cascade Ent. Ltd.................................................. 9
Ram Mechanical Ltd....................................................... 32
B.g.e. Service & Supply Ltd.......................................... 11
Refrigerative Supply Ltd................................................ 29
Belimo Americas............................................................. 32
Reliable Controls Corporation.................................... IBC
Canstar Restorations........................................................ 3
Roofing Contractors Association of B.c....................... 17
Craven Huston Powers Architects................................. 38
Royal Stewart Ltd............................................................ 18
D.g. MacLachlan Limited.............................................. 21
Schoolhouse Products................................................... 25
Erv Parent........................................................................ 22
Shanahan’s...................................................................... 23
Esc Automation & Delta Controls........................... OBC
Shelter Modular.............................................................. 31
Fortis B.c........................................................................IFC
Shutters & Shades.......................................................... 33
Grundfos Canada...................................................... 41
Soprema Inc.................................................................... 39
Ibc Technologies....................................................... 4, 21
Spears Sales & Service Ltd............................................ 32
Interior Turf Equipment................................................. 33
Viessmann Manufacturing Company Inc...................... 35
J.m. Bean & Co Ltd........................................................ 30
Wesclean Equipment & Cleaning Supplies Ltd........... 23
Korolite Engineered Panel Structures Ltd. C/o Massonville Plastics Ltd. & Group Of Companies........ 37
WESCO Distribution/Philips Lighting............................. 7 Western Bus Parts & Services Ltd................................. 27
McGregor Hardware Distribution................................. 19
Winmar.............................................................................. 5
Ops Talk • Fall 2014
