CCP CCP Plumbing & Mechanical Systems

Question 1

During commissioning of a domestic hot water (DHW) system, what minimum temperature must storage water be maintained at to prevent Legionella growth per ASHRAE 188?

Accepted Answer

140°F (60°C)

Answer

100°F (38°C)

Answer

120°F (49°C)

Answer

160°F (71°C)

Question 2

What is the primary purpose of commissioning a domestic water pressure-reducing valve (PRV)?

Accepted Answer

To confirm the PRV maintains downstream pressure within the design range under varying flow conditions

Answer

To increase water pressure for upper floors

Answer

To test backflow preventer operation

Answer

To verify water meter accuracy

Question 3

A commissioning agent is verifying a hydronic heating system. What does 'delta-T' refer to, and why is it significant?

Accepted Answer

The temperature difference between supply and return water, indicating heat transfer efficiency

Answer

The pressure drop across the heat exchanger

Answer

The difference between indoor and outdoor temperatures

Answer

The temperature rise across the boiler heat exchanger only

Question 4

What is the purpose of a backflow preventer, and what commissioning test confirms its function?

Accepted Answer

It prevents contaminated water from flowing back into the potable supply; tested by a certified backflow preventer test

Answer

It increases water pressure; tested by flow measurement

Answer

It filters sediment from domestic water; tested by pressure drop measurement

Answer

It regulates hot water temperature; tested by thermostat calibration

Question 5

During commissioning of a chilled water system, why is air purging of the hydronic loop critical?

Accepted Answer

Trapped air causes pump cavitation, reduced flow, noise, and poor heat transfer in hydronic coils

Answer

Air purging improves the chemical treatment effectiveness

Answer

Air purging is required only for steam systems

Answer

Air must be added to maintain system pressure

Question 6

What is the purpose of chemical water treatment in a cooling tower system, and how is it verified during commissioning?

Accepted Answer

To control scale, corrosion, and biological growth; verified by reviewing the water treatment program and testing water chemistry

Answer

To increase cooling tower efficiency by adding surfactants, verified by flow testing

Answer

To reduce water consumption, verified by metering

Answer

To improve condenser water temperature, verified by thermometer readings