At Master Fan Corp. all products are electronically balanced after fabrication. Components are first stand balanced then after assembly, the fan / blower is carefully aligned and balanced. All Fans / blowers should have final field vibration check and trim balance after installation to insure that no damage occurred in transit. After Fan is serviced, it should be Trim Balanced. At Master Fan Corp. all "Baseline Vibration Readings" are produced and shared with customer.