### Asset Description:
Fan: A machine used to create flow within a fluid, typically a gas such as air. Fans are commonly used to provide ventilation, cooling, or heating in buildings and industrial processes.

### Conditions:
- Fan Running
- VFD Speed % > 97%
- OAT < 80 °F
- Littleton: OAT > 40 °F

### How long the conditions were met:
Met for 2 Hours

Analyse the given conditions of the presented asset and select the option that MOST likely gives the reason for the conditions?
A. Fouling of stack and heat transfer surfaces
B. Undersized system for load
C. Too much equipment in the local area
D. Check condition of the filters


# Answer

Answer: B. Undersized system for load

Guidance Rationale: 
The fan is running, and the Variable Frequency Drive (VFD)
speed exceeds 97%, indicating that the fan is operating near maximum capacity.
Despite this high-speed operation, the outside air temperature (OAT) is below
80 °F, and in the Littleton region, the OAT is still above 40 °F—conditions that
should not demand such extreme fan performance under normal system sizing. The
fact that the fan has been running at this level for 2 continuous hours suggests
that the system is struggling to meet the load requirements, likely due to being
undersized for the current thermal or airflow demand. 

This sustained strain is not consistent with transient inefficiencies such as filter clogging (Option D),
which would typically cause intermittent performance issues rather than
sustained high-speed operation. Additionally, fouling of stack and heat transfer
surfaces (Option A) would likely result in reduced efficiency rather than the
fan running at near-maximum capacity for an extended period. The presence of too
much equipment in the local area (Option C) might increase the load, but it
would not explain the sustained high-speed operation unless the system was
fundamentally undersized to begin with. Therefore, the most likely explanation
is: "Undersized system for load."