Good one to bring up, Val. But I noticed something very odd here... and not do to with the submission itself. Take a look at when this was last updated. I'm sure I'm not the only only one who sees something wrong with that.
It appears Manfred is some sort of time-traveller. Good job, Man.
This could be a real boon to a kingdom if large enough. Rather then a storage chamber, it could be used as an ice-maker. With enough capacity, you ave now given a kingdom refrigeration and increased their food preservation abilities dramatically, which an in turn change population and power balance.
Simple yet very powerful. Nicely done!