Another similar scenario would be a refrigeration system containing air, as in Table 3. Air is a noncondensable and will get trapped in the top…
Table 2 shows a refrigeration system with a dirty condenser causing restricted airflow over the condenser. A similar condition would be a defective condenser fan…
Table 1 shows an R-134a refrigeration system with an overcharge of refrigerant. Notice the 30 degrees of liquid subcooling backed up in the condenser. Because…
A VAV system, as shown in Figure 10, controls temperature in a space by varying the quantity of supply air rather than varying the supply…
While maintaining constant airflow, single-duct constant volume systems change the supply air temperature in response to the space load (Figure 9). Single-Zone Systems. The simplest…
Vibration and sound isolation equipment is required for most central fan installations. Standard mountings of fiberglass, ribbed rubber, neoprene mounts, and springs are available for…
common complaint regarding buildings is the lack of outside air. This problem is especially a concern in VAV systems where outside air quantities are established…
Either axial flow, centrifugal, or plug fans may be chosen as supply air fans for straight-through flow applications. In factory-fabricated units, more than one centrifugal…
Humidifiers may be installed as part of the central station airhandling unit, or in terminals at the point of use, or both. Where close humidity…
Reheat systems are strongly discouraged, unless recovered energy is used (see ASHRAE Standard 90.1). Reheating is limited to laboratory, health care, or similar applications where…