POST 00644E : FROM HFC/CFC TO HC-BASED REFRIGERATION

POST 00644E : FROM HFC/CFC TO HC-BASED REFRIGERATION Follow-up on Posts 00487E, 00493E, 00500E, 00513E, 00634E and 00638E 29 February 2004 _____________________________________ Alejo Bejemino (mailto:[log in to unmask]) from UNICEF/Afghanistan discusses advantages and disadvantages of HC refrigerant. _____________________________________ I have read articles on HC-based refrigerant and the advantages that are worth noting for are the following: 1. HC refrigerant is found to be environmental friendly ( non-ozone depleting and no-global warming potential). 2. HC refrigerant charge is only 40% of the HFC equivalent. For example a vaccine refrigerator with a charge of 100 grams of HFC gas needs only 40 grams to run the same fridge. 3. HC refrigerant has a higher COP (coefficient of performance) in the vapor compression cycle than HFC. 4. HC refrigerant is compatible with all types of refrigeration oil. 5. HC has a higher flash point than HFC. What concerns me is the flammability of HC gases when it is mixed with the air in case of leakage problem. This may not be a serious problem for small fridge and freezers of 300 liters capacity in a cold room which is open. However this may be different for walk-in units where the cold air is blown by the fan and if the leakage happens to be in the evaporator inside the walk-in unit. In case this new refrigerant will be used for vaccine cold chain refrigeration units, I suggest that advance information, orientation and training should be conducted at the users level. Thanks and regards. Alejo Alejo H. Bejemino EPI Cold Chain Consultant UNICEF Afghanistan ______________________________________________________________________________ Visit the TECHNET21 Website at http://www.technet21.org You will find instructions to subscribe, a direct access to archives, links to reference documents and other features. ______________________________________________________________________________ To UNSUBSCRIBE, send a message to : mailto:[log in to unmask] Leave the subject area BLANK In the message body, write unsubscribe TECHNET21E ______________________________________________________________________________ The World Health Organization and UNICEF support TechNet21. The TechNet21 e-Forum is a communication/information tool for generation of ideas on how to improve immunization services. It is moderated by Claude Letarte and is hosted in cooperation with the Centre de coopération internationale en santé et développement, Québec, Canada (http://www.ccisd.org) ______________________________________________________________________________