"Increased energy use" is not a popular phrase with people responsible for large comfort cooling chillers. "Down time" is even further down on the list.

Unfortunately, recent research suggests that three refrigerant contaminants - moisture, oil, and rust - contribute more to bringing these ugly phrases to life than previously thought.

A contamination problem combined with a delivery delay made for double trouble for one Oklahoma hospital.

The Chiller's In The Mail

The hospital had ordered two new chillers and removed one of its older systems in preparation for the new units. However, the new chillers wouldn't be delivered for six weeks, and the one remaining system had begun to perform poorly. The manufacturer was called in, and moisture was detected in the refrigerant.

Those involved realized that that moisture could combine with lubricating oil in the compressor to form acids that attack the motor windings, or it could remove copper ions from tubing and deposit them on bearing surfaces, causing them to seize. Those and other problems are magnified even further by new alternative refrigerants, which have the capability to absorb greater quantities of water.

In hopes of solving the problem, the manufacturer called in technicians from Hudson (Pearl River, NY). The contractor installed fittings, and Hudson technicians connected the ZugiBeast, a system designed to remove moisture from the refrigerant side of a chiller system while on-line. All significant moisture was removed in less than 24 hrs, and everyone went home happy.

Moisture Strikes Back

However, a check of the refrigerant two weeks later indicated the moisture had already returned to unacceptable levels. What was thought to be a slow tube leak was apparently much more serious.

A normal response in this situation would be to hire a rental chiller for the four remaining weeks until the new equipment arrives. But hospital management wanted to protect their patients from the inevitable noise associated with installation. They also wanted to avoid the expense of a rental unit. At that point, Hudson engineers contacted hospital officials and offered to connect and operate the ZugiBeast full time, much like a dialysis system, until the new chillers arrived.

It was an unorthodox tactic, but given the options, officials decided it was the best avenue. Hudson connected the equipment and ran the unit on-line for the last month, keeping moisture levels at safe levels.

When the new chiller arrived and was installed, the old system was shut down for dehydration and removal. All in all, the remedy allowed the hospital to maintain quality performance for its patients and staff, plus save money by avoiding rental costs while keeping up the required 24-hr service. ES