First time on this forum so please bear with me if i dont speak to lingo.

I have designed a freezer cold room assembly using the following.

We have 2 x 40ft reefer containers which we have cut open the sides. There is a 3rd 20ft reefer on top of one of the 40's. We have spaced the 40ft reefers apart and enclosed the space in between with KingSpan insulation walls and ceiling.

We have cut open one 40ft reefer and hung down a plastic curtain.

We are having problems with the freezer we have cut open in that its condenser is not freezing over?

I have briefly spoken to the reefer supplier and they have indicated that the refrigeration units will not work properly if we have no air seal? Is this correct? And if so is there anything we can do to get around this?

Ideally we wanted the space in the actual containers to be approc -5C and the area in between the containers (Cold Store) to be -2 to +5C?

I would really appreciate some help on this?

Thanks Adrian