[L6]_Heating Hydronic Design & Boilers

Question 1

IND405

What is the definition of a Hydronic System?

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Answer 1

Hydronic Systems are fluid (typically water) systems which use hot or cold water to move heat to or from a conditioned space or process.

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Question 2

IND405

What is the most common type of hydronic heating system used in modern buildings today?

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Answer 2

Recirculating Hydronic Heating System

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Question 3

IND405

What is the simplest reason hydronic heating systems are more efficient than forced air systems?

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Answer 3

Hydronic Heating Systems are radiant heating systems rather than convection heat transfer systems.

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Question 4

IND405

Why is water a better medium for heat transfer than air?

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Answer 4

Water is 23.5 times more efficient at transfering heat than air.

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Question 5

IND405

What is the operating circulation supply temperature for hot water in a radiant floor heating hydronic system?

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Answer 5

90°F (dB)

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Question 6

IND405

What is the common ∆T (°F) for a hydronic heating system?

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Answer 6

∆T of 20°F (dB)

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Question 7

IND405

What are the three (3) steam hydronic heating systems?

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Answer 7

1. Low-Pressure (15-psig or less)
2. Medium-Pressure (16 to 50-psig)
3. High-Pressure (50-psig or greater)

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Question 8

IND405

What is considered high-pressure steam heating system by NYC Building Code?

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Answer 8

Any steam heating system over 15-psig.

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Question 9

IND405

How much radiant energy is given off by the image shown below?

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Answer 9

30% Radiant Heat Energy

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Question 10

IND405

How much radiant energy is given off by the image shown below?

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Answer 10

60% Radiant Heat Energy

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Question 11

IND405

What does LPS stand for?

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Answer 11

Low Pressure System

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Question 12

IND405

What is the minimum pitch required for a steam heating system to function properly?

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Answer 12

No less than 1-inch per 40-ft of linear piping length.

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Question 13

IND405

Name five (5) core components required for a steam heating hydronic system.

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Answer 13

1. Boiler
2. Deaerators
3. Surge Tanks
4. Flash Tanks
5. Steam Traps

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Question 14

IND405

What is the typical chimney exhaust stack required for one (1) large steam boiler?

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Answer 14

16-inch diameter

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Question 15

IND405

What is NYC Local Law 43?

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Answer 15

The required ban of the following fuel oils.
* In 2015, Fuel Oil #6 was banned from all use.
* In 2030, Fuel Oil #4 will be banned from all use.

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Question 16

IND405

Name the five (5) common types of hydronic piping arrangements.

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Answer 16

1. One-Pipe
2. Two-Pipe
3. Parallel
4. Series
5. Reverse-Return

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Question 17

IND405

What is the typical formula used for calculating heat transfer in a fluid?

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Answer 17

Q = 500 x GPM x ∆T

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Question 18

IND405

What is the typical Btu/hr per 1 GPM of heating water with a ∆t of 20 (°F)?

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Answer 18

10,000 Btu/hr

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Question 19

IND405

What are the temperature and pressure ranges of the following?
* Low-Temperature System
* Medium-Temperature System
* High-Temperature System

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Answer 19

• LTW: 0°F to 250°F & 0-psig to 160-psig
• MTW: 250°F to 350°F & 0-psig to 160-psig
• HTW: >350°F & 300-psig

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Question 20

IND405

What are the essential components of hot water hydronic system?

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Answer 20

• Heating Loads
• Source Equipment Selection
• Expansion Chamber
• Pump System
• Distribution System

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Question 21

IND405

What does LMTD stand for?

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Answer 21

Logarithmic Mean Temperature Difference

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Question 22

IND405

What is the maximum allowable a heating system source should be sized based on the heating load calculation?

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Answer 22

+20% greater than the heating design load requirement.

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Question 23

IND405

What are drain waste heat recovery exhangers used for?

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Answer 23

A heat exchanger which can recover heat from hot water used in showers, bathtubs, sinks, dishwashers, and clothes washers to be inserted to the HWR line for a hot water heater tank.

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Question 24

IND405

What are the four (4) types of boilers commonly installed?

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Answer 24

1. Water Tube Boilers
2. Fire Tube Boilers
3. Power Exhaust Vent Condensing Boilers
4. Direct Vent Condensing Boilers

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Question 25

IND405

What does TDR stand for?

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Answer 25

Turndown Ratio

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Question 26

IND405

What is the formula for calculating TDR?

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Answer 26

TDR = 100 x (Minimum Equipment Capacity/Full Equipment Capacity)

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Question 27

IND405

What is the maximum hot water supply temperature from condensing boilers?

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Answer 27

130°F

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Question 28

IND405

What are the three (3) types of expansion tank for a hydronic system?

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Answer 28

1. Closed Tank
2. Open Tank
3. Diaphragm Tank

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Question 29

IND405

What is the standard density of water?

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Answer 29

8.33 lb/gal

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Question 30

IND405

Which pump type can process thousands of GPM; in-line centrifugal circulators or base mounted centrifugal pumps?

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Answer 30

Base mounted centrifugal pumps

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Question 31

IND405

What type of pump is shown in the image?

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Answer 31

Vertical In-Line Dual Arm Pumps

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Question 32

IND405

How many pump law formulas are there?

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Answer 32

Three (3) pump law formulas
1. GPM2 = GPM1 x (RPM2/RPM1)
2. HEAD2 = HEAD1 x (RPM2/RPM1)^2
3. BHP2 = BHP1 x (RPM2/RPM1)^3

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Question 33

IND405

True or False: Parallel pumps work at the same head and supply their share of system flow at that pressure.

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Answer 33

True.

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Question 34

IND405

What is the total capacity each pump is required of the total flow rate for a parallel pumping system?

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Answer 34

80% of the total GPM design flow

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Question 35

IND405

What are primary and secondary pumping systems used for?

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Answer 35

1. They let the designer set water temperatures and temperature ranges in different system components.
2. Hydraulic decoupling simplifies control, operation, and analysis of big systems.
3. Circuits can be designed for different purposes.

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Question 36

IND405

What are the four (4) typical hydronic piping distribution layouts?

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Answer 36

1. Full Series
2. Diverting Series
3. Parallel Direct Return
4. Parallel Reverse Return

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Question 37

IND405

What is the difference between a hot water and steam hydronic heating system?

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Answer 37

Hot water hydronic systems circulate water heated in a boiler to radiators or baseboards. Steam is heated and circulated through pipes to radiators, where it condenses and releases heat in a steam hydronic system.

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Question 38

IND405

What are the advantages of using a high-efficiency condensing boiler in a hydronic heating system?

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Answer 38

High-efficiency condensing boilers extract more heat from combustion, saving energy and money.

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Question 39

IND405

What is the difference between a closed-loop and an open-loop hydronic heating system?

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Answer 39

An open-loop hydronic heating system draws in fresh water and discharges it after use, while a closed-loop system circulates a fixed amount.

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Question 40

IND405

How does a thermostatic radiator valve (TRV) work in a hydronic heating system?

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Answer 40

Room temperature controls radiator hot water flow with thermostatic radiator valves. When the room is warm enough, the TRV cuts hot water, saving energy and money.

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