system cooling capacity

hello all

hope can get some advice

1.From freon system the total unit of evap expansion device, can determind the cooling capacity for a coldstorage at -25 deg C. ???

2. example for ammonia coldstorage and we have..

- 2 unit high stage 200kw 1 duty, 1 standby and 1 unit 125kw booster
- 4 unit low stage 55kw

how do we determind the cooling capacity ???

Thanks in advance