17-19: Should EDF Switch from EN 14705 Long Term Performance Tests to ATC-105As the owner of 32 large cooling towers, EDF has been performing its own thermal performance acceptance tests during the past 30 years. The company invests a lot in verifying as accurately as possible that a cooling tower reaches the guaranteed year average performance. EDF uses a long term test procedure developed by EDF Research department during the 80s. Long Term means data acquisition running from 3 to 9 months which implies specific attention