Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


Regarding Refrigeration system

Regarding Refrigeration system

Regarding Refrigeration system

we r using Refregeration fluid 30% glycol and 70 percent water as coolent liquid . Checking if we increase the Glycol water ratio to 40-60 .OR 50-50 GLYCOL WATER ratio. IS t cooling time will reduce .pls suggest. What is plus and minus when we increase the glycol content. Tnanks

RE: Regarding Refrigeration system

Higher glycol will reduce the heat capacity of the fluid, increase fluid viscosity, and thus lower heat transfer. 50/50 is pretty standard for most applications because it is close to providing the optimum balance of pluses and minuses. Staying under 50/50 is usually better than going over unless you require the lower freezing point. Glycol also costs more than water.

RE: Regarding Refrigeration system

For transferring heat, no fluid even comes close to being as good as water. It has an amazing heat capacity. From the perspective of maximizing heat transfer, the ideal concentration of glycol is zero. The only reason glycol is added to coolant systems is because water has the unfortunate property of freezing at 0 degC. Glycol lowers the freezing point of the coolant system so that it can be operated at lower temperatures, without freezing. So, if you need to operate at a lower temperature, then proceed with considering a higher glycol concentration. But, the trade-off will be poorer heat transfer. That's the price you pay for operating at a lower T. To compensate for that, run the coolant at a higher flowrate, or modify the exchanger to acheive a higher heat transfer coefficient. If your system is operating well, and you want to improve the heat transfer, then consider changes to the heat exchangers (to get a higher U value), or consider reducing the glycol concentration if that can be done without getting too close to the freezing point.

RE: Regarding Refrigeration system

At higher viscosity, piping friction losses will also increase, so the pump flow (at a given speed) will reduce. As glycol content increases, the viscosity increase will be even more at startup/lower operating temperatures.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close