A 45-degree branch enters directly into a VAV inlet and causes bad readings

A VAV inlet needs stable air entering the sensor area. An angled short entry can spin the air and make the box read wrong.

Stop if

• VAV [number] has a 45-degree entry right at the inlet and TAB readings may be unstable. I checked the inlet path. Do you want a straight rigid spool added before the box?

Watch out

• Do not slam an angled fitting directly onto a VAV inlet and expect stable CFM readings.

Check

• Check if an elbow or 45 enters directly at the VAV collar.
• Look for short flex or offset right at the inlet.
• Confirm airflow arrow and sensor tubing are correct.
• Ask TAB/foreman if readings are unstable.
• Provide straight rigid inlet run where the project/detail requires it.

Steps

• Check if an elbow or 45 enters directly at the VAV collar.
• Look for short flex or offset right at the inlet.
• Confirm airflow arrow and sensor tubing are correct.
• Ask TAB/foreman if readings are unstable.
• Provide straight rigid inlet run where the project/detail requires it.

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