Hi and TIA: How many BTU's of cooling do I need for an open office space of approximately 25' x 45' with 11' ceilings, 4 windows (double glazed) approximately 36" x 72" being used as an art gallery? Location is NYC. Exposure is facing south from 5th floor.

Thanks.

ron kahn

2.5 ton will do it, unless you are going to have allot of lights. Computers, people on the move and lighting can greatly increase the heat load on the system.