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Glycol content in Cooling system

Glycol content in Cooling system

Glycol content in Cooling system

I would like to know what is the effect of over dose and under dose of glycol in the cooling system.Is there any effect if the existing glycol will be mixed with different gycol such as frost gycol.

RE: Glycol content in Cooling system

RME1997: A 50-50 mixture of ethylene glycol and water, by volume, is generally considered the opimum for freeze protection of -34 Deg F.  Anything less than 50-50 raises the temperature at which the glycol/water mixture will freeze.  When ethylene glycol has had anti-corrosion and other addditives added to make anti-freeze a 50-50 mixture is also considered best for corrosion protection.  The boiling point for a 50-50 mixture is 225 Deg F.  Increasing the pressure, as in an automobile cooling system to 15 psig raises the boiling temperature to 252 Deg F. for a 50-50 mixture.  Ethylene glycol is more expensive than water so unless lower freeze protection is needed, anything over a 50-50 mixture is a waste.  Less than 50-50 may also reduce corrosion protection.


RE: Glycol content in Cooling system

All true.  However, from an cooling standpoint, the real effect is reduction in cooling capacity.  Glycol does not have as much specific heat capacity as water.  On marginal systems, this can be significant.

RE: Glycol content in Cooling system

What is 'frost' glycol? Are you talking about mixing ethylene glycol with propylene?

I agree to 50% is ideal for freeze protection. Unless the pipes are actually being designed to work outside we usually specify a 30-35% concentration as this will provide 'burst' protection down to -36F or so.

RE: Glycol content in Cooling system

agreed on 50/50 being ideal for most applications.  
60/40 is the max we have ever used in Arctic applications.

RE: Glycol content in Cooling system

The other problem with too much glycol is that the visocity increases and pump power will go up and flow rates go down.

Mixing glycols may or may not be a problem.  It is best not to do it.

= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection

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