|
Klaczek,
Wayne and Mark Ackerman. “VAV
Sensors & Ductwork: Placement and Pitfalls.”
Engineered Systems, February 2006, pp.
54-58.
|
In
this article, the authors describe the problems
that can affect VAV sensor response and loss of
amplification. Recommended solutions include:
-
Minimize obstructions and transitions before VAV
terminals to improve system accuracy.
- Concentric
reducers should never be used. This is especially
important in critical environments, such as isolation
rooms and biocontainment labs, where accurate
airflow is essential for system performance.
- Since
VAV boxes are more susceptible to flow errors
at or near the minimum flow set point, select
the smallest box possible to provide the maximum
required airflow or use multiple boxes when large
variations in flow are required.
- Providing
10D of unobstructed duct before a VAV terminal
does not compensate for upstream transitions.
The required amount will vary from 10 to 40D,
depending on the required flow rate.
Download
the full article here. PDF file (545 KB)
|
|
Thibodeau,
Allison. “Dust and VAV Crossflow Sensor
Don’t Mix.” TAB Journal,
Fall 2005, p. 22. |
Describes
a real-world experience where the author found the
readings in a laboratory varied from the original
air balancing settings because of dust in the VAV
crossflow sensor. She reminds readers to check for
dust in VAV box sensors if they are having problems
duplicating their readings. She also reminds readers
that before they clean a VAV box or controller,
they should contact the manufacturer to verify the
maximum air pressure that can be applied. |
Traccel
