In what three ways does the human body lose its heat
Evaporation
Convection
Radiation
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
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
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
what creates circulation in a forced hot water heating circulation system
booster pump
what are two advantages of using a higher temperature heating system
small size radiation units
small pipe sizes can be used
What is pressure drop
The amount of pressure lost between any 2 points in a system
What causes pressure drop
The friction created between the inner walls of pipe and fittings
The liquid flowing through them
How is pressure drop expressed
Pounds per square inch
Feet of water
Milinch
What is a milinch
1/12000 of a foot
1/1000 of a inch
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
What is static pressure
Weight of water in the system, equal to .433 psig per foot of height above the guage
What is meant by type RC baseboard
Extended convection heating surface
heat is supplied by both radiation and convection
List four advantages of using baseboard radiation
inconspicuous
clean in operation
minimum of interference with furniture placement
distributes the heat near the floor
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
What is the preferred location for convectors
They are located, as much as possible, on the outside walls and under windows--biggest heat loss
Why is the length of piping important in a hydronic system
To be able to size the pump and piping
What purpose does the piping layout serve
it shows the location of the boiler
location of the room units
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
*A compression tank is not necessary in a system if a pressure reducing valve is used
False
*Plug relief valve if it continues to drip
False
*Water temps in a closed hydronic heating system does not affect the size of radiation of piping
False
*The BTUH output of a boiler can be increasedby raising the boiler water temp
False
*The BTUH carrying capacity of a pipe decreases as the velocity of water in the pipe increases
False
Why must the number of gallons per minute to be circulated through the system be determined
Determine the size of the pump and piping
In hydronic heating system how much of the system must be considered when figuring resistance
Total equivalent length of the longest circuit
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
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
list the reasons why the location chosen for separating air from water in at the boiler
the temperature is highest and velocity is lowest
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
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
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
where may the boiler be located in a hydronic heating system
at any convenient location
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
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
