TinnerFlow™2nd YearVAVs & Fan CoilsYELLOW · Check First
You need a minimum of 3 to 5 straight, uninterrupted duct diameters of straight round pipe before entering the VAV box inlet. * If you place an elbow or a sharp transition directly on the inlet collar, the air will spin turbulently, causing the flow sensor tubes inside the VAV inlet to read incorrectly, ruining the system balance.
You need a minimum of 3 to 5 straight, uninterrupted duct diameters of straight round pipe before entering the VAV box inlet. * If you place an elbow or a sharp transition directly on the inlet collar, the air will spin turbulently, causing the flow sensor tubes inside the VAV inlet to read incorrectly, ruining the system balance.
Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.