What is the meaning of cold room with / Without Door Step?

The cold room without door step is; if there is a equivalence between out corridor and room’s inner height , we apply frames to theree edges of rooms( right-left-up). so this is the door withour door step.

-The trans palette – system and drift will easier on the door-steps.

– The door gaskets are on the left side – up side – right side and under the door there is mopboard gaskets. The higher of our units that the lower of inner units. So the door with door-step is prefered.