How often do you change the Glycol in your systems?

[wineglow]

How often should the glycol be change in long draw glycol systems? I have read every two years, MM says every 8 months to a year. Also, I know a refractometer is the most accurate way to check the glycol mix but they are in the $150 to $200 range -- Has anyone tried using an automotive anti freeze checker made for propylene glycol and compared the results since they are under $10?

[Scott Zuhse]

Glycol mfgs. recommend every year. Many organizations who offer PM programs offer this service once a year as well. May sound like overkill but why risk a power pack overworking and downtime for a retailer.

The testers for automotive industry are not designed for propylene glycol. Reading may not be accurate.