Hydronic Systems

Card Set Information

Hydronic Systems
2014-05-07 23:48:52
Mid Term

Mid Term Test
Show Answers:

  1. In what three ways does the human body lose its heat
    • Evaporation
    • Convection
    • Radiation
  2. What are four advantages of heating domestic hot water heating boiler
    • Ample hot water 
    • Prevents deterioration
    • Helps keep the basement dry
    • No sudden break downs
  3. List two of the options available for summer cooling in conjunction with hydronic heating
    • Water chiller and fan coil until which distributes cool air
    • Combination heating and cooling units which circulate hot water in the winter and cool water in the summer
  4. What creates circulation in a gravity hot water heating system
    When water heated in the boiler increases in volume and rises simultaneously with a downward movement of the cooler heavier water in the return
  5. what creates circulation in a forced hot water heating circulation system
    booster pump
  6. what are two advantages of using a higher temperature heating system
    • small size radiation units
    • small pipe sizes can be used
  7. What is pressure drop
    The amount of pressure lost between any 2 points in a system
  8. What causes pressure drop
    • The friction created between the inner walls of pipe and fittings
    • The liquid flowing through them
  9. How is pressure drop expressed
    • Pounds per square inch
    • Feet of water
    • Milinch
  10. What is a milinch
    • 1/12000 of a foot
    • 1/1000 of a inch
  11. What is head pressure and how is it usually expressed
    • The maximum pressure drop in which the pump can induce flow
    • expressed in feet of water
  12. What is static pressure
    Weight of water in the system, equal to .433 psig per foot of height above the guage
  13. What is meant by type RC baseboard
    • Extended convection heating surface
    • heat is supplied by both radiation and convection
  14. List four advantages of using baseboard radiation
    • inconspicuous
    • clean in operation
    • minimum of interference with furniture placement 
    • distributes the heat near the floor
  15. What are two factors in addition to size and design on which the capacity of radiation units depend
    Temperature drop of water and temp of the water being circulated
  16. What is the preferred location for convectors
    They are located, as much as possible, on the outside walls and under windows--biggest heat loss
  17. Why is the length of piping important in a hydronic system
    To be able to size the pump and piping
  18. What purpose does the piping layout serve
    • it shows the location of the boiler 
    • location of the room units
  19. What are 4 items which must be included in the measurement of the circuits in a hydronic heating system
    • Vertical supply from the top of the boiler
    • each time the main goes up through the floor to the baseboard or goes down through the floor to the basement , 18" must be added
    • there is a vertical drop of 6' from the end of the ereturn to the boiler connection and all other piping which can be measured
  20. *A compression tank is not necessary in a system if a pressure reducing valve is used
  21. *Plug relief valve if it continues to drip
  22. *Water temps in a closed hydronic heating system does not affect the size of radiation of piping
  23. *The BTUH output of a boiler can be increasedby raising the boiler water temp
  24. *The BTUH carrying capacity of a pipe decreases as the velocity of water in the pipe increases
  25. Why must the number of gallons per minute to be circulated through the system be determined
    Determine the size of the pump and piping
  26. In hydronic heating system how much of the system must be considered when figuring resistance
    Total equivalent length of the longest circuit
  27. How does the determination of total equivalent length differ between the single-main and two pipe system
    • in the single-main system the TEL may be determined by finding the measurment of the longest circuit excluding run-outs and risers
    • in a two-pipe system the total resistance is the sum of the circuit piping resistance plus the convector resistance run-outs and risers
  28. what is one of the basic differences between single and two pipe mains
    • one pipe requires the use of diversion fittings 
    • none are used in a two pipe system
  29. list the reasons why the location chosen for separating air from water in at the boiler
    the temperature is highest and velocity is lowest
  30. how many expansion tanks should be installed if two or more boilers are used
    in field practice, several boilers can be connected to the same properly sized compression tank if there is a series of isolation valves in the header
  31. what are 4 functions of a compression tank in a forced hot water heating system
    • expand and contract
    • constant minimum pressure on the system
    • automatic air receiver and collection point
    • eliminated the need for the constant addition of water to the system
  32. What is the procedure to be followed when a compression tank becomes waterlogged
    isolate the system, open the compression tank drain valve and tank fitting vent screw or vent allow air to enter into the tank at the same time water is being drained from the tank
  33. where may the boiler be located in a hydronic heating system
    at any convenient location
  34. list one instance when heating mains be pitched
    in a one-pipe system, the mains must be pitched when all of the radiation is below the mains
  35. why must circulating pumps be lubricated after each installation has been completed
    proper lubrication of the pump at the factory is impossible, since there is no control over the position of the carton containing the pump while transit