Converting Glycol hydronic system into water system

[Sahkah]

Good day,
Wanted your help in identifying the consequences of converting a heating system from using glycol (35%Ethylene glycol mix) as a working fluid into using water . The old system (using glycol) used to incorporate a steam/glycol heat exchanger , pumps ,the piping distribution system and , the heating coils in multiple air handling units. The new system is no longer utilizing steam but using hydronic boilers(to directly heat the working fluid) as the main heating source and the rest of the components stay the same (piping , pumps, and heating coils) . Will the pumps and/or the piping (if using water) need to replaced? will the system utilizing water with the hydronic boilers is of higher efficiency than it would be when using glycol? Thank you in advance

 

[EnergyProfessional]

you lose the freeze protection, which I'm sure you are aware.

Other than that no drawback. On the contrary, water has better heat transfer, better heat capacity and is easier to pump. If anything you can reduce flow.

You need to add a chemical feeder to add corrosion inhibitors. Glycol systems usually don't have that. You likely want to add a water-make-up valve, but you also could use the existing glycol fill station.

 

[LittleInch]

If you do nothing then the flow will increase, perhaps significantly so whilst the pumps should be ok you may need to add some flow control valves to restrict flow back to what it was or maybe less than you had before as the energy density of water is higher.

So also temperatures may end up higher if you don't restrict flow.

Define efficiency.

With water you can transport more heat than with glycol but you may not need that if the system was designed for glycol.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[IRstuff]

One other thing that you might need to do is to manually add corrosion inhibitors. Typical glycol mixtures already include corrosion inhibitors because glycol is somewhat corrosive, but water doesn't.

You might need to reduce the pump speeds, since they were sized for glycol; pumping water is easier, so the pump may run faster and experience cavitation.

TTFN (ta ta for now)
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