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[L3]_Starting HVAC Calculations & Design Conditions Flashcards

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1
Q

IND405

Name the six (6) typical internal heat gain (loads) types.

[L3]

A
  1. Fan Energy Loads
  2. Ductwork Energy Transmission & Losses
  3. Light Fixtures
  4. Equipment Motor Loads
  5. Human Sensible & Latent Loads
  6. Plenum area

[L3]

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2
Q

IND405

Per ASHRAE what is the correct weather zone for Long Island, NY?

[L3]

A

Zone (4)

[L3]

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3
Q

IND405

Per ASHRAE which weather zone type is considered Dry?
* Zone (A)
* Zone (B)
* Zone (C)

[L3]

A

Zone B

[L3]

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4
Q

IND405

What is the best direction for a building to face in order to collect the greatest amount of solar irradiance thoughout the day on the northern hemisphere?

[L3]

A

South

[L3]

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5
Q

IND405

Name the state which has the highest temperature and humidity level. Also, define what is occuring at the selected state as well.

[L3]

A
  • State “O”
  • Fresh outside air is being introduced to the AC system during the summer time.

[L3]

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6
Q

IND405

What is the heating/cooling load calculation method required for residential and low-rise applications only?

[L3]

A

Manual J8, created by ACCA (Air-Conditioning Contractors of America)

[L3]

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7
Q

IND405

List the five (5) methods created for building HVAC load calculations.

[L3]

A
  1. Total Equivalent Temperature Difference/Time Average (TETD/TA)
  2. Transfer Function Method (TFM)
  3. Cooling Load Temperature Difference/Cooling Load Factor (CLTD/CLF)
  4. Heat Balance (HB) & Radiant Time Series (RTS)
  5. Manual J8 Method for Residential Applications

[L3]

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8
Q

IND405

Which heating/cooling load calculation method is the most difficult to complete by hand and requires a computer to complete?

[L3]

A

RTS (Radiant Time Series)

[L3]

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9
Q

IND405

W₁ = W₂, expresses what is occuring in an air stream?

[L3]

A

Humidity level remains constant and no additional humidty is added no removed thus only dB is changing on the psychrometric chart.

[L3]

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10
Q

IND405

When cooling & dehumidifiying a space, what change must occur with the temperature?

[L3]

A

The airstream’s temperature must be cooled and brought down below the dew point of the space.

[L3]

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11
Q

IND405

What is the name of the coil labeled (A)?

[L3]

A

Reheat Coil

[L3]

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12
Q

IND405

What does STC stand for?

[L3]

A

Standard Temperature Conditions

[L3]

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13
Q

IND405

What is the STC of dry-air and pressure as defined by ASHRAE?

[L3]

A

68-degrees (F) & 14.7 psia

[L3]

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14
Q

IND405

What is the STC density of dry-air and specific volume as defined by ASHRAE?

[L3]

A
  • Density of Dry-Air @ STC = 0.075 lb/ft³
  • Specific Volume of Dry-Air @ STC = 13.3 ft³/lb

[L3]

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15
Q

IND405

What is the fully expressed equation for Sensible Heat?

[L3]

A

qs = (Qx(60))x(0.075)x(0.24 + (0.45W))xΔt

[L3]

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16
Q

IND405

What is the industries expression for Sensible Heat?

[L3]

A

qs = 1.10xQxΔt

[L3]

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17
Q

IND405

What is the fully expressed equation for Latent Heat?

[L3]

A

qL = [(Q)x(60)x(0.075)x(1076 Btu/lb)]xΔW

[L3]

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18
Q

IND405

What is the industries expression for Latent Heat?

[L3]

A

qL = 4840xQxΔW

[L3]

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19
Q

IND405

Define a SCAV unit.

[L3]

A
  • Self Contained Air-Cooled Vertical Unit
  • A combined condensing unit and AHU which is vertically standing on the floor as one (1) unit in a single location.

[L3]

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20
Q

IND405

What is a single-zone system?

[L3]

A

Simplified systems are dedicated to one (1) area w/o central building controls to satisfy dB temperature w/o significant humidity control.

[L3]

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21
Q

IND405

Which ASHRAE codes dictates IAQ and Ventilation requirements?

[L3]

Study These Flashcards
A

ASHRAE 62.1 & 62.2

[L3]

22
Q

IND405

What are the two (2) types of generic ventilation required for any new project space?

[L3]

Study These Flashcards
A
  1. Natural Ventilation
  2. Mechanical Ventilation

[L3]

23
Q

IND405

Expressed in formulas, list the three (3) scenarios for ventilation.

[L3]

Study These Flashcards
A
  • Scenario #1 - Qsrv = Qor/Xo
  • Scenario #2 - Qsrv = Qsr
  • Scenario #3 - Qsrv = Volume (FT3) * (ACH/60)
  • Scenario #4 - Qsrv = K * (CFM/FT2)

[L3]

24
Q

IND405

What formula is used for the indoor exhaust air is the most important aspect of the design for your space, ie. laboratory?

[L3]

Study These Flashcards
A

Scenario #2

[L3]

25
# IND405 What is the name of the **HVAC component** in this system schematic diagram used to balance the total **air-flow**? ## Footnote [L3]
Manual Volume Damper ## Footnote [L3]
26
# IND405 List the **three (3)** types of **fire-stopping** methods used for HVAC ductwork. ## Footnote [L3]
1. Motorized Fire Dampers 2. Spring Loaded Curtain Fire Dampers 3. Ductwork Fire-Stopping Retaining Angles ## Footnote [L3]
27
# IND405 What is the definition of **ASHRAE Standard 55**? ## Footnote [L3]
Standard 55 specifies conditions for acceptable thermal environments and comfort zones as is intended for use in design, operation, and other occupied spaces. ## Footnote [L3]
28
# IND405 What is the definition of a **Comfort Zone** per ASHRAE Standard 55? ## Footnote [L3]
The optimal range/combinations of thermal & personal factors (clothing and activity level) with which at least 80% of the building occupants are expected to express satisfaction. ## Footnote [L3]
29
# IND405 What does **SBS** stand for and its **definition**? ## Footnote [L3]
* Sick Building Syndrome * The number of possible health issues or illness generated during the occupancy of a building due to uncomfortable indoor building conditions. ## Footnote [L3]
30
# IND405 List **five (5) typical sysmptoms** of SBS illness. ## Footnote [L3]
1. Mucosal Irritation 2. Asthma 3. Nose Bleeds 4. Chest Tightness 5. Headache ## Footnote [L3]
31
# IND405 What is the defined **typical internal core temperature of the standard person** per ASHRAE 55? ## Footnote [L3]
98.6°F ## Footnote [L3]
32
# IND405 What is the **mean skin temperature** of comfort for a typical human per ASHRAE 55? ## Footnote [L3]
88°F to 96.8°F ## Footnote [L3]
33
# IND405 What is the **maximum allowed temperature swing** before discomfort occurs for a typical person? ## Footnote [L3]
±2.5°F ## Footnote [L3]
34
# IND405 What is the recommended **Summer Indoor Design Condition**? ## Footnote [L3]
75°F dB & 50% RH ## Footnote [L3]
35
# IND405 What is the recommended **Winter Indoor Design Condition**? ## Footnote [L3]
70°F dB & 20% to 30% RH ## Footnote [L3]
36
# IND405 What is the **Clothing Insulation range** recommended for **Winter** & **Summer**? ## Footnote [L3]
* Winter = 0.8 to 0.9 * Summer = 0.5 to 0.6 ## Footnote [L3]
37
# IND405 How much **time** is required per **ASHRAE Standard 55** to define a **space qualified for long term occupant use**? ## Footnote [L3]
A minimum of 15-minutes. ## Footnote [L3]
38
# IND405 List the **six (6) factors** per **ASHRAE 55** related to **Thermal Comfort**. ## Footnote [L3]
1. Metabolic Rate 2. Clothing Insulation 3. Air Temperature 4. Radiant Temperature 5. Air Speed 6. Humidity ## Footnote [L3]
39
# IND405 What is the formula for calculating a **specific person's metabolic rate** per ASHRAE 55? ## Footnote [L3]
## Footnote [L3]
40
# IND405 **True or False:** The insulation factor of the clothing we wear everyday has a maximum limit of time to maintain our personal body temperature comfortably from the outdoor environment? ## Footnote [L3]
**True**, it is calculated as the Tmax, lcl of clothing insulation ## Footnote [L3]
41
# IND405 Is **65°F dB @ 50% RH** inside or outside the **Summer Comfort Range**? ## Footnote [L3]
Outside ## Footnote [L3]
42
# IND405 What is the **typical (°F) temperature range** an office **main lobby entrance** is to save energy during the summer? ## Footnote [L3]
4°F to 6°F ## Footnote [L3]
43
# IND405 What is the **minimum temperature (°F)** allowed during the **winter** for a **Garage** per ASHRAE 55? ## Footnote [L3]
40°F (dB) ## Footnote [L3]
44
# IND405 What is the recommended design conditions all year around for hospital operating rooms per ASHRAE 55? ## Footnote [L3]
72°F @ 55% RH ## Footnote [L3]
45
# IND405 Are hospital operating rooms required to be **positively, negatively, or neutrally pressurized** facilities? ## Footnote [L3]
Positively Pressurized ## Footnote [L3]
46
# IND405 What are the **two (2) temperature base references** when calculating using **Degree-Day method**? ## Footnote [L3]
65°F & 50°F ## Footnote [L3]
47
# IND405 What is the **HDD** for just **one (1) day** when the **outside** temperature is **12°F** for **HDD50** & **HDD65**? ## Footnote [L3]
* HDD50 = 50°F - 12°F = 38°F * HDD65 = 65°F - 12°F = 53°F ## Footnote [L3]
48
# IND405 What are the **formulas** for **HDD** & **CDD**? ## Footnote [L3]
* HDD = (Tbase – Ta) x No. Days * CDD = (Ta - Tbase) x No. Days ## Footnote [L3]
49
# IND405 At what speed does the **Wind Chill** effect **stop increasing**? ## Footnote [L3]
Any speed 43 mph or greater. ## Footnote [L3]
50
# IND405 Are **degree-days** a unit of time? **Yes** or **No**. ## Footnote [L3]
No, degree-days are a unit of time & temperature. ## Footnote [L3]

HVAC Systems_FA23 (11 decks)

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