Hello,
I have two questions regarding a district cooling system to be used in one of our projects:
1- Can we use 0.51% value for Refrigerant leakage rate and 2% for end of life refrigerant if the district cooling provider's studies clearly show such numbers (it seems to me this is the case although I've recently heard this was not possible anymore)?
2 - The diversity factor of the district cooling provider is 67%. This means that even though around 100MW (28,400 tons) of cooling capacity is installed, they sell approximately 150MW of cooling capacity to their customers. When calculating the refrigerant charge, should we include the diversity factor ? This would seem logical as the district cooling system is equivalent to the installations of numerous systems totaling a 150MW cooling capacity (hence the same quantity refrigerant for a larger amount of cooling capacity).
Many thanks for your help!
Ante Vulin
Sustainability ManagerYR&G
80 thumbs up
May 14, 2013 - 1:33 pm
Roland -
For #1 - the NC reference guide was revised several years ago to not allow project teams to use alternate leakage rates. In my personal opinion, the change targeted manufacturer's claims about new equipment. EBOM, on the other hand, requires you to use actual leakage rates. I would first check if your project can comply with the credit using default leakage rates. If so, great. If the project doesn't earn the credit,you could try checking the box for "Alternative Compliance" and provide a set of calculations with the measured leakage rate. I've never tried this, but it might work if you provide very good documentation about the leakage history.
For #2, you should use the installed capacity of the actual chilling equipment - i.e. 100 MW.
And in general, be sure to check the version of the District Energy guidelines that were in effect at the time the project was registered.