Ventilation in a cold room

[Vivek Pandey]

I am designing a cold room of size 4 m by 2.5 m by 2.5 m. The cold room will be used to store vegetables. The recommended Air change is 4 changes in a day. How do I go ahead with exhaust ducting? Do I need to have an exhaust fan? Also, I want to have control over the outflow of exhaust depending upon CO2 concentration in the room. Kindly guide through.

[B G Scott]

This is a very small store to be considering controlled atmosphere.
To control the environmental conditions within a CA store you would need a scrubber but this is usually only applied to large fruit stores.

The store of your size will have a lot of door opening for staff to gain access to the product, in general terms this will take care of your air changes, and from a design perspective the requirement to allow for air changes is add this load to the other components of the refrigeration load to ensure that the selected plant has the capacity to maintain the design conditions.