Hydronics Piping Systems And Calculations

Question 1

Described the difference between a Gravity feed and a forced feed System

Answer 1

• Gravity: uses the coller heavier water to push that warmer lighter water back up (all rads must be above the boiler)
• Forced: uses pumps to force water through the system (rads can be placed anywhere)
  Used in: one pipe systems, series loop, two pipe systems, and radiant floor heating

Question 2

Mono Flow System:
- is a 1 pipe or 2 pipe system?
- how is the piping ran
- what is the special tee used on this system called? and where is is located?
- what does said tee to to the water
- what setting is this system typically installed in?
- What are the advantages? (list 3)
What are the disadvantages (list 2)

Answer 2

Mono Flow System:
- single Pipe Systems
- Piping ran in a loop, with radiators being fed by tees/risers
- Uses a special tee called a “Monoflow Tee” on the return
- Monoflow tees increase the velocity and decrease pressure
- Mostly used in residential
- Advaneges: Less piping, cheaper, each unit can be individually controlled
- Disadvantages: Branch lengths have to be limited because of friction, and The last unit will receive less heat then the first because of heat loss

Question 3

Series Loop Baseboard Systems (perimeter loop):
- is a 1 pipe or 2 pipe system?
- Describe how this system work
- what setting is this system typically installed in?
- Advantages (list 2)
- Disadvantages (list 2)

Answer 3

Series Loop Baseboard Systems (perimeter loop):
- 1 pipe system
- Ran in series (no take offs) every thing is a part of the main
- Mostly used in residential
- Advantages: less pipe needed, less installation cost
- Disadvantages: Major loss of heat in units so by the last the water is very cool, and Temperature control is limited to one device

Question 4

Split Series Loop System:
- is a 1 pipe or 2 pipe system?
- how is this different from a Series loop?

Answer 4

Split Series Loop System:
- 1 pipe system
- To compensate for the heat loss in a Series loop system you can split the series loop into a circuit
- Series splits off shortly after boiler supply and then joins together again shortly before the boiler

Question 5

Baseboard Radiation:
- is a 1 pipe or 2 pipe system?
- Read Card

Answer 5

Baseboard Radiation:
- 1 pipe system
- Baseboard radiation is normally rated in BTU per hour per linear foot based on 65º F room air entering the unit and on the temperature of the water supply
- The amount of baseboard required depends on the heat loss of a particular location

Question 6

Direct Return System:
- is a 1 pipe or 2 pipe system?
- Describe how piping is ran
- Advantages (list 2)
- Disadvantages (list 2)

Answer 6

Direct Return System:
- is a 2 pipe system
- Piping ran in a loop with one pipe as supply main and one pipe as return main
- First supplied is first on return
- Advantages: Each unit gets the same supply temperature and individual controls can be installed
- Disadvantages: Prone to short circuit, so must be properly balanced

Question 7

Reverse Return System:
- is a 1 pipe or 2 pipe system?
- Describe how piping is ran
- Advantages (list 2)
- Disadvantages (list 1)

Answer 7

Reverse Return System:
- is a 2 pipe system
- Piping ran in a loop with one pipe as supply main and one pipe as return main
- First supplied is Last return
- Advantages: Provides even distribution, without balancing issues and can have individual controls for each unit
- Disadvantages: this system has more piping which makes it more expensive

Question 8

Protection from Dead Head:
Wild Loop:
- How is it piped
- does it need a zoning valve?

Bypass:
- how it it piped, what device does it use?
- how does this device work and where is it located on the piping

Answer 8

Protection from Dead Head:
Wild Loop:
- A piping connection between supply and return that prevents dead head
- The wild loop will not have a zoning valve on it they are commonly located in crawl spaces

Bypass:
- Another way to avoid deadheading is to install a pipe between the supply and return Headers with a Differential Pressure Regulator on it.
The valve is normally closed but if all zoning valves are closed it will open in response to the higher pressure. They are installed close to the boiler, downstream of the pump

Question 9

Boiler Loops and Zoning:
- Primary Loops are?
- Secondary loops are?
- Tertiary loops are?
- What can loops also be called?

Answer 9

Boiler Loops and Zoning:
Distribution piping can be broken down into zones
- Primary Loop: is the main distribution line
- Secondary Loop: can take off from the primary
- Tertiary Loop: takes off from the secondary
- Loops can also be called circuits

Question 10

Piping coefficients:
- coefficient for copper?
- coefficient for steel?

What is the Formula for Linear expansion?

Answer 10

Piping coefficients:
- Copper = 0.0000095
- Steel = 0.0000072

Formula for Linear expansion :
Length of pipe (in feet) x Coefficient x Change in Temp