Why are zone control systems used? What will be an ideal ...

[kwoodring]

Why are zone control systems used?
 
  What will be an ideal response?

Question 2

Using Figure 71-25, select a floor register that will provide an 8 to 10 foot throw for 150 CFM with a face velocity less than 700 feet per minute.
 
  What will be an ideal response?

[tuate]

Answer to Question 1

Zone systems allow control over different portions of the house without installing multiple units. This improves overall comfort, saves energy, and reduces installation cost versus installing two systems.

Answer to Question 2

4 x 14 shows 140 CFM with 8.5foot throw at 600 FPM and 160 CFM with 10 foot throw at 700 FPM, Therefore, 150 CFM should have a throw of a little over 9 feet with a velocity of 650 FPM.

6 x 10 should also work it should have about the same throw with slightly less velocity than the 4 x 14.

[kwoodring]

Great answer, keep it coming

[parshano]

TYSM