Closed versus open glycol system

[dwollner]

We currently have (5) 7bbl fermenters and a dual stage heat exchanger that our closed loop glycol system operates. We are looking to add additional capacity and was wondering about an open non pressurized glycol loop.
Any thoughts on efficiency, should we isolate the heat exchanger, or just build a redundant closed system?
Thank you,
David

[Starcat]

System Specifics

David, I have worked on Scores of Closed Water loops but have never seen a closed glycol loop so its a curiosity as to the design.
Closed loops require a ready and constant makeup fluid supply on demand or they can go down very fast if a slight fluid loss happens without a makeup fluid induction means. Chilled water loops always have a makeup water system ON LINE to keep the closed system pressure at a constant in the event of a leak, and every larger scale system leaks to a degree.
With open loops, a small leak will not take the system down.
Since we need to be able to add glycol at any potential time and it does not come pressurised out of a pipe, a return well at atmospheric seems to be the most sensible way to go.

[dwollner]

Our system works well as a closed glycol loop and has for 17 years but you are correct that a leak drops the pressure and we usually need to pump in either more glycol or add city water under pressure. Thank you!