Online Access Free CEM Exam Questions

An air conditioning unit cools make-up air from 25°C (dry bulb temperature) and 50% relative humidity down to 13°C. What type of heat has been removed from the air?

• A.No heat energy has been removed
• B.Sensible heat
• C.Both sensible and latent heat
• D.Latent heat

What instrument is NOT used to measure temperature?

• A.Optical pyrometer
• B.Thermometer
• C.Thermistor
• D.Bimetallic thermometer
• E.Hot-wire anemometer

A concentrating solar thermal system collects 5 GJ/h of thermal heat, which is delivered to a 94% efficient hot water generator. The hot water generator is used to raise the water temperature from 15°C to 65°C. The specific heat of water (Cp) is 4.2 kJ/kg-°C. What flow rate (liter/second) of hot water can be delivered from the hot water generator?

• A.6.2 liter/second
• B.12.0 liter/second
• C.9.2 liter/second
• D.4.2 liter/second

The set point for the chiller supply water temperature is varied as a function of the thermal demand for space cooling. What do you call this control strategy?

• A.Night setback
• B.Reheat coil reset
• C.Chilled-water temperature reset
• D.Condenser-water temperature reset

A 100-kW packaged engine-generator combined heat and power (CHP) system has the specifications listed below. What is the annual purchased fuel cost for the CHP system, assuming that the CHP is electrical output limited and operates at full electrical load all year?

SELECT THE CORRECT ANSWER

• A.$52,222/yr
• B.$32,668/yr
• C.$28,900/yr
• D.$58,300/yr
• E.$43,776/yr