Caleffi Idronics
Idronics N. 18


Water Quality in Hydronic Systems

Water is the essential fluid in all hydronic systems. Its quality affects the system’s efficiency, reliability, life expectancy, and the effectiveness of any chemical additives.  There is a “physical” aspect to water quality, and a “chemical” aspect.

The physical aspect involves procedures for ridding systems of gasses and solid impurities. The devices involved include dirt separators, air vents and magnetic separators.  These have been discussed in previous issues of idronics, and most recently in idronics #15.  To complement that information, the focus of this issue of idronics is on the chemical aspects of water quality.

The need for water treatment in today’s hydronic systems appears to be widely recognized. A 2014 poll of Coffee with Caleffi™ webinar attendees (contractors and designers) gave the following responses to the questions:

When do you choose to treat the initial fill water? 
     On most installations                 64%
     On some installations                28%
     Never                                          8%

When you treat initial fill water, what method do you prefer? 
     Add chemicals                             50% 
     Demineralize                               22%
     Soften                                          22%
     Combination or different method   6%

There were also many “write-in” questions submitted during this poll.  These responses and questions revealed that while most hydronic heating professionals understand the need for water treatment, many do not know which approaches are required or preferred.

This issue of idronics was developed to address these concerns.  It discusses problems that can develop within hydronic systems when water quality is ignored.  It lays out procedures for converting raw water into high quality water. Emphasis is placed on demineralization for preparing water for use in hydronic systems. It concludes with procedures for testing, flushing, washing, demineralizing, and final adjustment of water quality.  The objective is to ensure that the water within the system can provide optimal performance over many years of operation.

We hope you enjoy this 18th issue of idronics and encourage you to send us feedback by emailing us.