I designed three of these systems in Northern Alberta for 1000 HP pumps and are currently designing three more.
We learned a few things along the way and have a good design strategy in place now.
You are on the right track with recirculation.
Anyone work on ventilation design for this application?
Looking to substantiate a minimum 1 cfm/ft2 as per the uniform building code. My preference is a 4 ach to give it more ventilation.