Question 1

The economizer is able to increase or decrease the amount of outside air that is brought into the structure with two ____.

Accepted Answer

The economizer uses two dampers to control the amount of outside air that enters the building. These dampers are called the fresh air damper and the return air damper. By adjusting the position of these dampers, the economizer can increase or decrease the amount of outside air that is brought into the structure, which can help to reduce energy costs and improve indoor air quality.

Question 2

Many rooftop package units are equipped with multiple ____________________ fans.

Accepted Answer

The answer of Many rooftop package units are equipped with...

Question 3

Explain the term "free cooling."

Accepted Answer

The answer of Explain the term "free cooling."...

Question 4

The temperature sensor used in chilled-water VAV systems to detect when the outside air is cold enough to cause freezing, is typically called a(n) ____________________.

Accepted Answer

The answer of The temperature sensor used in chilled-water VAV...

Question 5

Name the four common types of VAV boxes.

Accepted Answer

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Question 6

How do variable refrigerant flow (VRF) systems modulate the volume of refrigerant that is pumped through the system?

Accepted Answer

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Question 7

With both fists in front of the body, pointing the thumbs outward tell the crane operator to ____ the boom.

Accepted Answer

Pointing the thumbs outward mimics the motion of extending the boom outward.

Question 8

The water coil in a dry cooler can contain 100% water or can be a mix of water with  ____________________.

Accepted Answer

The answer of The water coil in a dry cooler...

Question 9

When multiple rooftop units are used to condition the air in a building, it is common practice to label the units and their corresponding ____________________.

Accepted Answer

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Question 10

What are some drawbacks of adding more antifreeze than needed to prevent freezing in the chilled water piping system?

Accepted Answer

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Question 11

A frame that is used to mount HVAC equipment is called a(n) ____________________.

Accepted Answer

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Question 12

____ are intended to help provide the correct amount of ventilation and also help reduce cooling costs by allowing outside air to be introduced to the conditioned space when conditions are correct.

Accepted Answer

The given statement is describing the function of economizers, which are specifically designed to help reduce cooling costs by introducing outside air when appropriate. Minimizers, maximizers, and recirculators do not have this specific function.

Question 13

An enthalpy sensor includes solid state temperature and ____ sensors.

Accepted Answer

An enthalpy sensor typically includes temperature and humidity sensors to measure the total heat content in the air.

Question 14

Explain the purpose of the relief fan.

Accepted Answer

The answer of Explain the purpose of the relief fan....

Question 15

By tapping his fist on his ____, the crew member is telling the crane operator to use the main hoist.

Accepted Answer

Tapping the fist on the head is a signal used in crane operations to indicate the use of the main hoist. This is a standardized gesture in crane hand signals to ensure clear communication between the crew member and the crane operator.

Quiz 50: Commercial Rooftop, Packaged, Variable Refrigerant Flow, and Variable Air Volume Systems