[L4]_Indoor Air Quality (IAQ), Ventilation, & Contaminants

Question 1

IND405

(Yes or No) It is possible to have a scenario where HVAC equipment heat gain loads can be larger than the combined space loads of a project?

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Answer 1

Yes.

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Question 2

IND405

What is the most common type of ventilation for existing building projects?
* Natural Ventilation (Passive Ventilation)
* Mechanical Ventilation

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Answer 2

Natural Ventilation

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Question 3

IND405

What is the largest heat gain or loss in terms of system loads?
a) Miscellaneous heat gain
b) Ductwork heat gain
c) Outdoor air introduced in mechanical ventilation

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Answer 3

Outdoor air introduced in mechanical ventilation

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Question 4

IND405

List three (3) advantages of using a DOAS system in HVAC?

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Answer 4

1. Improved indoor air quality
2. Reduced energy consumption
3. Better humidity control

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Question 5

IND405

What is the purpose of a mixing box in HVAC systems?

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Answer 5

A mixing box is used in HVAC systems to mix outdoor and indoor air for ventilation purposes. This helps to maintain indoor air quality while minimizing energy consumption.

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Question 6

IND405

What is ASHRAE Standard 62?

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Answer 6

ASHRAE Standard 62 sets air quality standards for commercial buildings. Airflow, filtration, and humidity control are recommended.

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Question 7

IND405

What is a humidistat in HVAC?

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Answer 7

Humidistats measure the amount of moisture in the air inside. It works like a timer for humidity. Humidistats can turn on or off humidifiers and dehumidifiers to keep the air inside comfy and healthy.

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Question 8

IND405

What is the recommended DOAS coil face FPM?

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Answer 8

The DOAS coils should be sized for 400-FPM maximum velocity, have broad fin spacing (8
fins per inch maximum), and have flat plate fins for easy fouling inspection and cleaning

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Question 9

IND405

What is the Crack Method used for in heat loss calculations?

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Answer 9

It is used to calculate the infiltration through cracks in the building envelope.

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Question 10

IND405

What does ACH stand for and what is its purpose?

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Answer 10

Air Changes per Hour; it calculates the volume change out of an entire room to determine ventilation needs.

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Question 11

IND405

What are the two types of calculation methods for Mechanical Ventilation?

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Answer 11

Ventilation Rate Procedure (VRP) and Air-Changes Method

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Question 12

IND405

What are the steps involved in the Indoor Air Quality Procedure (IAQP)?

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Answer 12

1. Identify relevant Contaminants of Concern (CoCs)
2. Identify sources and emission rates
3. Specify concentration limits
4. Apply an indoor air cleaning solution
5. Conduct a mass-balance analysis

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Question 13

IND405

Name the four (4) benefits of a Balanced Ventilation System

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Answer 13

1. Improved Indoor Air Quality
2. Comfort
3. Health
4. Lower energy bills

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Question 14

IND405

What is the VRP equation?

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Answer 14

Vbz=(Rp×Pz)+(Ra×Az)

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Question 15

IND405

What are the variables required to calculate the outdoor air intake as per VRP?

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Answer 15

• Number of people in the zone (Pz)
• The required outdoor air per person (Rp)
• The floor area of the zone (Az)
• The required outdoor air per unit area (Ra)

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Question 16

IND405

How does VRP address different space requirements for ventilation?

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Answer 16

VRP utilizes specific ventilation rates for different types of spaces by considering the occupancy level and the floor area, ensuring tailored ventilation that meets the unique needs of each space for adequate indoor air quality.

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Question 17

IND405

What is the primary function of an Energy Recovery Ventilator (ERV)?

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Answer 17

An ERV transfers both heat and moisture between incoming fresh air and outgoing exhaust air, optimizing the indoor air quality and comfort while minimizing energy loss.

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Question 18

IND405

How does a Heat Recovery Ventilator (HRV) differ from an ERV?

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Answer 18

An HRV primarily transfers heat (not moisture) between incoming and outgoing air streams, making it ideal for climates where moisture control is not a critical issue.

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Question 19

IND405

What are the energy efficiency implications of using ERVs and HRVs?

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Answer 19

By recovering heat and moisture (ERVs) or just heat (HRVs) from the exhaust air, these systems reduce the energy required to heat or cool incoming fresh air, leading to lower energy bills and improved comfort.

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Question 20

IND405

What are the two ways outdoor air quality (OAQ) levels affect IAQ?

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Answer 20

1. Regional Air Quality: Evaluating an entire region’s outdoor air quality level determined by NAAQS tests.
2. Local Air Quality: Due diligence surveys for additional concentrated local contaminant sources.

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Question 21

IND405

What historical factors have led to the establishment of minimum outdoor air supply rates?

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Answer 21

The need to control moisture, carbon dioxide, odors, and tobacco smoke has historically led to establishing a minimum rate of outdoor air supply per occupant to ensure adequate IAQ.

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Question 22

IND405

What are the six (6) pollutants that are evaluated by the National Ambient Air Quality Standards?

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Answer 22

1. Carbon Monoxide
2. Lead
3. Nitrogen Dioxide
4. Ozone
5. Particle Pollution
6. Sulfur Dioxide

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Question 23

IND405

What is CoC?

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Answer 23

Contaminants of Concern

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Question 24

IND405

What is the ASHRAE Standard which governs particulate removal of filters?

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Answer 24

ASHRAE Standard 52.2

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Question 25

IND405

What is an example of a sorbent filter material regarding IAQ?

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Answer 25

Simple Activated Carbon Filter

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