Figure 1 shows a building layout with seven zones. Three zones have an eastern exposure (5, 6, 7), four zones have a western exposure (1, 2, 3, 4), two zones have a northern exposure (4, 5) and two zones have a southern exposure (1, 7). You can control this building from a single constant volume air handler because all the zones have the same exterior exposure. The layout lacks entirely internal zones making similar load requirements for each zone.
Figure 2 shows a building with seven zones. Four of the zones have a northern exposure (1, 2, 3, 4) and the other three zones have a southern exposure (5, 6, 7). It is best practice to install two separate zoned RTUs because northern and southern exposures have different effects on a building. The solar load is larger on the southern exposure than the northern exposure.
Figure 3 shows a combination manufacturing facility and office area. Two RTUs control the space temperature in the individual zones, numbered 1 through 7. One RTU controls the interior Zones 2, 3, and 4. Another RTU controls exterior Zones 1, 5, 6, and 7. A single constant volume RTU is used for each of the Zones 8 through 12.
