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Sorry for the rookie question, but i recently got the danfoss refrigerant slider app to help with day to day pressure checks ect.
I have asked a few other engineers that i work with and no one can seem to give me a direct answer and it seems they dont really understand it either.
Basically when you choose the gas type you can select either bubble or dew, what am i supposed to be using to work out the correct running pressures?
Any help would be much appreciated
Rik
Knowledge of what you are measuring.
Knowing the difference between bubble or dew points is fundamental to working with refrigerants.
So im guessing this all refers to the subcooling and superheating side of the refrigerants?Quote:
Originally Posted by FaultCode
As Brian says you need to know what you are measuring.
Basically when using the dew point info you measure the evaporator superheat , when measuring the condenser liquid subcooling you use the bubble info.
The reason is with the new type gases such as R407c etc which are made from 3 different refrigerants ,the pressure / temperature relationship is not constant as like the good old R12, R22 etc. This is called the temperature "glide" which some of these gases have a glide of 6k so you have to know if its the dew point or the bubble point you need to use.
Brilliant, thanks for your help, i have done a little research into it and it does make sense now so thanks to you both for your helpQuote:
Originally Posted by Glenn Moore
Think: "dewperheat" dewpoint for superheat, and "Bubcooling" bubblepoint for subcooling
Rep point added my friend.
I like your way of remembering the difference.
Tricky.
Asking when not sure shows initiative,
Those you asked not knowing!
Scary!
Not to forget that when you calculating heat exchanger TD-s you should use midle between buble and dew point.