Net Refrigeration Effect.

[Burrah Boy]

Can someone explain, if I have a net refrigeration effect of say 67btu/lb using R22, that I plotted on a PH chart, how can I determine the size of the system from this data. EG, is it a 12000 btu/hr system. What incriments is the 67btu/lb taken as, per sec, per min, per hr?
Thanks

[US Iceman]

The value for Net Refrigeration Effect (NRE) is per pound (or kilogram). This is only the first step in determining the required mass flow per Ton (or kW) of cooling.

Mas flow has the following units; mass per unit of time. Therefore the mass flow is determined on any one of the following; second, minute, or hour. Once you find the mass flow you simply multiply the mass flow by the required cooling capacity required. That would be the total mass flow for that cooling capacity.