Don’t throw away heated or cooled conditioned air from such areas as clean rooms or hospitals that have high fresh air requirements due to potential contamination. These commercial & industrial facilities may have heat or cold temperature reclaim possibilities by using Cross flow heat exchangers that transfer heat or cold temperatures from exiting air flows to incoming fresh air make-ups. This especially possible where the exiting and incoming air flows are in relatively close proximity to one another. When heat reclaim is utilized properly approximately 80% of the exiting conditioned heat or 50% of the exiting conditioned cooling can be transferred to the incoming air streams. Therefore, when regulations require high fresh air intake, heat or cooling reclaim can offer an excellent payback potential.