Exhaust Fans

Well.
By definition if they are exhaust fans they must both be removing air from the building.

In reality it depends where they are situated relative to each other and how well the building is sealed.

Del

The building has two big opening,like drive in on each end,fans will in top of eve, trying pull heat away from workers with in building.floor space is 300X300 roughly

Most of those type fans have louvers that close when not running. They are there to keep the weather out and heat in during the winter. The force of the air opens them. Reversing the direction one of the fans blows will just suck them closed. You would get no air at all unless you remove them. That would defeat their purpose.

not sure if i understood the question, but i supposed if you meant that to be exhaust, then the fans should worked to take the air away from the room.

was the "pulling & pushing" meant to better circulate the air in one direction? would that thus mean a supply & exhaust (supply on one corner and the exhaust on the furthest opposite corner)

the direction of the fan mounted will affect the direction of flow. as stated by others, two large holes would have easily allow air to come and go naturally, unless theres a fair bit of heating that you would like to take it away with a "forced air-circulation within the room itself?"

If you have one 'pushing' and one 'pulling' as you state then you have only the volume of one fan circulating but you raise the total pressure difference.

Why do you want the circulation?

You will have double the volume of flow if both fans are mounted the same way.

If you need positive pressure in the warehouse the fans should be 'pushing' into the warehouse. This is done to prevent unwanted dust to enter the warehouse and the air can be filtered prior to entering the area.

If you want negative pressure in the warehouse the fans must be 'pulling' or exhausting. This is used if you do not want the air from inside to escape from the area.

If you need to refresh the air 'pushing' it has a better effect as you create turbulance inside the building. Suction or 'pulling' is not very effective as it only moves the air close to the fan and the air in the rest of the building is left almost stationary.