What type of blower can be used to provide more air movement when heating and cooling systems have been turned off?
Variable-speed
(True or False) The third step for duct system balancing preparation is to obtain data pertinent to motors, fans, diffusers, and grilles that are not given on drawings.
TRUE
(True or False) Rectangular ducts usually have the advantage of saving room space and are easier to install in walls.
TRUE
When balancing a duct system, what are balancing instrument, along with a pressure probe, can be used to determine fan static pressure?
Velometer
What type of duct system allows individual room conditions to be maintained from a central system, by blending hot and cool air through automatically controlled mixing devices?
Double
What type of material is used to make duct systems?
Galvanized sheet steel
Fiberboard
Aluminum sheets
All of the above (correct answer)
What type of gravity ventilator may be roof-mounted?
Stationary
Pivoting wind-directional
Rotating-turbine
All of the above (correct answer)
What air balancing instrument indicates air pressure by employing the principle of balancing a column of liquid of know weight against air pressure?
Manometer
(True or False) Certain areas of a building, such as hallways and bedrooms, should have a slightly less positive pressure to reduce the spread of odors.
FALSE
The velocity of a high-pressure duct system is usually limited to how many feet per minute (fpm)?
4,000
The velocity of a low-pressure duct system is generally less than how many feet per minute (fpm)?
2,000
(True or False) Fiber glass duct constructed of molded-glass fibers should never be coated with vinyl or other plastic coatings.
FALSE