HVAC engineer designer

Job ID: 34326113

Budget: £250 – £750 GBP

Looking for a simple design for a simple ventilation system for 23 affordable rentable workspaces in Uk, each unit is 7.4m x 3.5 x 3.2m and on average will have 1 to 2 people working in them.
I am looking for the calculation on fresh air in and extract.
So I can plan the ducting sizes! Or ever better if you can advice on the ducting,
I have attached a layout of the run of the ducting it is on the 3 page of the floor plan