Air Balancing Flashcards
What’s TAB stand for
Testing,adjusting, and balancing
Hvac airflows and pressures meet the design of
Equipment manufacturer
In some instances a variable motor can consume how much power annually
85 less then single speed
What two measurements are in a pilot tube
Static pressure
Total pressure
Inner tube of the pilot tube measure what
Total pressure
Outter part of the pilot tube measure what
Static pressure
A delimiter measure what kind of reading
FPM
Velometer can be used where
Fume Hoods, grills, diffuser and slots on ventilation
Velometer can only measure up to
10” wc
Can a Velometer be used for gas mixture
No
Two most basic anemometers are
Thermo
Rotating vane
Thermal anemometers method is to measure air velocity by
Heat transfer from small wire immersed into the air
Rotating vane anemometer measure in what
Linear foot or meters
Barometers ( flow hoods) can measure to what value
0- 2000 CFM
What’s
Ps
Pt
Pv
Static pressure
Total pressure
Velocity pressure
Static pressure is best described
Potential energy
Total pressure is best described
Sum of all energy
How can velocity pressure be found
Velocity pressure minus static pressure
What’s used to measure accurate airflow
Pilot tube
Who much straight duct is needed before taking a measurement
6-10 duct diameters
Pilot tube should always be pointed into the
Airflow
What’s the minimum and maximum amount of reading to be done
12-64
If there’s any insulation on the outside of the duct it need to be
Subtracted
Round duct can use how many reading
Two readings
Where should reading be in round duct
Vertical and horizontal not directly in the middle of pipe
If flow hood cannot be used what other one can be used
Rotating vane
Readings should be taken how far apart
Equal spacing four inch apart
What’s AK factor mean
Area factor
After measurements are done the diffuser can be
Marked and labeled at the diffuser
Which ever method is used it must meet what
Specifications for testing , adjusting, and balancing
Three things to make sure is done before balancing
Specifications and mechanical drawing
Label grills on prints
Startup has been completed
Diffusers and grills and dampers should all be open before what
Balancing the system
What should blower speed be set at to check system
High speed
Total CFM must operate between 80 - 120 of its total design true or false
True
