by
Robert Garment, Executive Editor | October 21, 2016
From the October 2016 issue of HealthCare Business News magazine
However, Siemens also outlines the technical specifications such as water flow, the heat load capacity, etc., in their system Planning Guide, so customers can make their own purchasing decisions for water cooling. Metellus says over the years Siemens has worked with “KKT Chillers, Dimplex Thermal Solutions, Filtrine, Arctic Chill and many others. They’ve all been good partners.”
Nestel of Hitachi says, “I would say 90-95 percent-plus go with the chiller we offer as an option with the system.” Virtually all MRs have their own dedicated chiller. But there are a few exceptions. Nestel notes, “Some people do run multiple machines off one large cooling source, like a big water tower on the roof. But we don’t recommend that for an obvious reason: if you have a problem with your tower, suddenly you’ve got a whole mess of problems on your hands.” “I’ve seen Duke University Hospital do that, run everything off one big main cooling tower, the air conditioning, the MRs and everything,” says Taylor, “but I don’t recommend that mainly because the MRs and coldhead get neglected.”
Water-cooled or air-cooled?
It is well known in the industry that about 80 percent of the chillers used in health care are air-cooled chillers, and 20 percent are water-cooled. Installation issues are a major reason air-cooled chillers dominate. “Air-cooled chillers can go just about anywhere. They can go outdoors on the roof or at grade level, where there’s plenty of space.
The majority of chillers are air-cooled packaged systems, where everything is in one cabinet, nice and neat,” notes Turner Hansel, vice president of sales for Filtrine. Water-cooled chillers need to be connected to the facility’s cold water system, which complicates installation and adds to the cost. Air-cooled chillers can stand alone. “A lot of hospitals don’t have room for an indoor water-cooled chiller,” notes Hansel. They also require more ongoing regular maintenance. While air-cooled chillers typically cost a little more to buy, the total cost of ownership is lower over the long run.
Redundancy and backup
Since chillers are vital components of imaging equipment, it makes sense to think about the benefits of redundancy and backup systems. Tony Trumblee, medical account manager at Dimplex Thermal Solutions, says Dimplex is one company that believes in complete redundancy. “To us, redundancy means having dual refrigeration circuits, so we have twice the capacity the MR needs. We have two compressors, two pumps, two heat exchangers. If one cooling circuit goes down, the MR can run on our second cooling circuit.”
