AFE Building Systems & Maintenance 2

Question 1

A facility manager notices that a chiller's coefficient of performance (COP) has dropped from 5.2 to 3.8 over six months. What is the most likely cause?

Accepted Answer

Condenser fouling reducing heat transfer

Answer

Condenser fouling increases condensing temperature and pressure, reducing the COP by forcing the compressor to work harder.

Question 2

Which maintenance strategy uses real-time sensor data to trigger service actions only when equipment performance degrades beyond a threshold?

Accepted Answer

Predictive maintenance

Answer

Predictive maintenance uses continuous monitoring data (vibration, temperature, oil analysis) to intervene before failure while avoiding unnecessary scheduled downtime.

Question 3

What does a building automation system (BAS) economizer cycle do during mild outdoor conditions?

Accepted Answer

Uses outdoor air to provide free cooling instead of mechanical refrigeration

Answer

An economizer cycle opens outdoor air dampers when outside enthalpy or temperature is favorable, reducing or eliminating mechanical cooling loads.

Question 4

A 120V single-phase motor draws 8 amps at full load. What is its approximate input power in watts?

Accepted Answer

960 W

Answer

Power (W) = Voltage × Current = 120V × 8A = 960 W for a purely resistive or unity power factor load.

Question 5

Which type of fire suppression system is best suited for a data center to minimize equipment damage?

Accepted Answer

Clean agent (e.g., FM-200 or Novec 1230)

Answer

Clean agent systems suppress fires using gaseous agents that leave no residue and do not damage sensitive electronic equipment.

(AFE) Association for Facilities Engineering Certification Practice Test

(AFE) Association for Facilities Engineering Certification Practice Test

AFE Building Systems & Maintenance 2