Hydronic Heating Period 2 (CND) Flashcards
What section of the ASME code do low temperature boilers fall under?
Section 4 of the ASME code.
True or False: Low Temperature boilers are usually gross rated?
False
The heat added to any form of matter that does not change its state but does change its temperature is called?
Sensible Heat
How many BTU’s of latent heat must be added to 10 pounds of water to change it to steam?
9700 BTU’s (10 pounds x 970 BTU’s = 9700 BTU’s)
To take 100lbs of water at 40F and heat it to 120F would require how many BTU’s?
8000BTU’s (120F-40F=80x1=80x100lbs=8000BTU’s)
True or False: 20.685Kpa is equal to 3psi?
True
Water is most dense at?
4C or 39.2F
What would be the likely cause of a boiler to over pressure?
Ruptured diaphragm in a bladder type expansion tank.
The color code for Type H copper pipe is?
White
Using the rule of thumb for bladder style expansion tanks what size of tank would be required for a heating load of 500,000 BTUh?
71 US Gallons
The type of boiler that can be used for space and domestic water heating is known as a?
Hybrid Boiler
What is the height restriction for an indirect fired blow through unit heater?
No Higher than 12”
As water is heated, its volume?
Increases and specific gravity decreases
An imperial gallon of water weighs 10lbs. How much does 18 cubic feet of water weigh?
1125lbs (18ft3 x 62.4lbs=1125lbs) *1ft3=62.4lbs
True or False: The term ASME stands for The American Society for Testing and Materials?
False: ASME - American Society of Mechanical Engineers
True or False: Boiler trim falls under section 4 of the ASME code?
False
1000 boiler horsepower is equal to ______BTU’s?
33,475,000BTU’s (1Hp = 33,475BTU’s)
A flow switch should be installed on a copper tube boiler when the exceed?
400,000BTUh
A BTU (British Thermal Unit) is?
The amount of heat energy required to raise 1lb of water 1*F.
A wall 8’x10’ has a combined R-value of 68 what is the U-factor?
U=0.0147
(U=1/R)
(U=1/68)
What is found on a high limit control that is not found on a opening control?
A manual reset button
All boiler make up water must be protected from cross connections by the means of?
Approved backflow preventer and D.C.V.A
What section of the ASME would you find boiler drain valves?
ASME 6
True or False: Draw through unit heaters can be installed in ceiling areas over 12’?
True
A boiler has a gross output of 427,000 BTU’s and an input of 750,000 BTU’s. What is its % efficiency?
56.9% (427,000/750,000=.569*100=56.9%)
The heating system where all the heating water passes through each heating unit is known as the ______ system.
Series loop system.
If a boiler has an input of 400,000 BTUh and is 98% efficient, what is its output?
392,000 BTU (400,000 x 98% or .98 = 392,000)
The amount of fuel consumed by a boiler is known as the ?
Input
True or False: High mass boilers can be low temperature or high temperature?
True
Modular radiant ceiling panels are available in two styles?
Even pass or uneven pass
Water will change to steam at what temperature?
212F or 100C
True or False: Smooth shiny surfaces will absorb radiant heat?
False
True or False: Expansion tanks are used to take up compression of the water in a heating system?
False
True or False: Dark rough surfaces will reflect radiant heat?
False
True or False: Guides and anchors are devices used to control expansion and contraction in piping system?
True
Unless specified, the temperature differential in a residential heating system is always?
20 Degrees
Which type of boiler extracts the latent heat out of the flue gases?
A high efficiency-condensing boiler
In a ______ heating system, the flow through one heat transfer unit cannot be shut off without stopping the flow through the other heat transfer units.
Series Loop heating system
True or False: Cavitation will not occur in a pump if the Net Positive suction head available (NPSHA) is greater than the Net Positive Suction Head Required (NPSHR)?
True
True or False: When two pumps are installed in parallel to each other, the system pressure will increase?
False
What is the flow required if you have a heat load of 186,350 BTUh, a supply temperature of 192F and a return temperature of 144F?
7.76gpm
(GPM = BTUh / 500lb/gpm x delta T)
(GPM=(186,350lbs x F) / 500lb/gpm x (192F-144*F)(GPM=186,350 / 24000gpm) Note-500lb/gpm is a constant
Which boiler is limited to a maximum working pressure of 30 psig (water) or 15 psig (steam)?
High mass cast-iron boiler
Within a hot water boiler, which device indicated pressure and temperature?
Combination Gauge
The device used to shut down the fuel to the burner when the water level in the boiler drops below its operating level is called a/an ___________ or a/an ________.
Float-operated low water cut-off or a Probe type low water cut off.
A globe valve pattern device that is used to reduce incoming water pressure to the minimum desired boiler system pressure and that also serves as an automatic water feeder is known as a _________ or _____.
Pressure reducing valve or PRV.
What are the maximum operating temperature and pressure of a low-temperature high mass cast iron hot water boiler?
120C (250F), 207kpa (30psig)
What is the maximum operating temperature and pressure of a low-temperature low mass copper or steel tube hot water boiler?
120C (250F), 1100kpa (160psig)
Low-temperature low pressure hot water boilers are usually rated in?
net BTU/hr or EDR
The amount of heat energy available at the heat transfer units is defined as?
The Net Rating
An EDR has a BTU valve of?
Steam 240 Btu/hr, Hot water 150 Btu/hr
The amount of heat energy consumed by the boiler is defined as?
The input rating
The piping system in which the heat transfer units are a part of the piping system is the?
Series loop
The name of the piping system in which the heat transfer units are a specialty tee is a/an?
One pipe
The name of the piping system in which the first heat transfer unit supplied is also the first returned is the ?
Two-pipe direct return
The name of the piping system in which the water travels approximately the same distance to each of the heat transfer units is the?
two-pipe reverse return
The major disadvantage of the series loop piping system is that it?
Has limited heating capacity for each circuit
The purpose of a balancing valve is to?
Adjust flow rates to each heat transfer unit.
The purpose of a wild loop is to?
Prevent the pump from dead heading.
The type of radiator valve that should be installed to prevent unauthorized use is a?
Lockshield Radiator valve.
The purpose of a zone valve is to?
Provide control of heat emission.
The part of a circulator that transfers energy to the water is?
The impeller
What is the function of a circulator in a hot water heating system?
Moves the water within the system
Two variables you will find on a pump curve are?
Head and Flow
The best location for the circulator in a hot water heating system is?
Downstream of the compression tank.
Finned tube baseboard is rated by what method?
BTU per foot hour based upon supply water temperature, flow rate and entrance air temperature of 65*F.
How do you control the heat output on finned tube baseboard?
By adjusting the damper.
What is the heat loss limitation for a series loop system?
60 to 70 MBH per loop
An are or portion of a heating system served be one or more loops and individually controlled.
Is called Zoning.
What are two types of hot water unit heaters?
Blow-through (Horizontal) and Draw-through (Vertical)
What is the recommended maximum installation height for a horizontal unit heater?
3.66m or 12ft
Where should heat transfer units be located?
Under windows, Next to doors, and In areas of high heat loss.
The transfer of heat from one object to another through an intervening space wherein the intervening space may not be heated (the processes of emission, transmission, and absorption of radiant heat energy).
Called Radiation
The 2 main types of ceiling radiant panels are?
Modular and Linear
Which radiant panel can have supply and return piping at the same end?
Any panel with an even number of tube passes
How can linear panels be used to achieve a 90 degree corner?
By using either the square corner or mitred corner method.
What are the 2 most common ways to accommodate thermal movement?
Offsets and expansion loops or bends and Mechanical expansion joints (Bellows and slip-type expansion joints)
List the 4 common ways of the non-mechanical method for expansion?
Pipe loops,
Offsets,
Expansion coil,
Change of direction.
Pipe installations can either be _______ or _________.
Free-floating or Restrained
Each change of direction in a pipeline offers some ________ that allows for some expansion.
Piping flexibility
Pipe loops and offsets are in ideal way to allow expansion; however, you should be cautious when the line connects to ______,_______ and _______.
Boilers, Header branches and Wall fins.
What must be considered when using slip joint expansion devices?
They must be installed in a accessible location so they can be serviced.
What is the most common rule to use when designing a non-problematic heating pipeline?
Keep the pipe the design as simple as possible.
As a rule the first pipe guide should be placed ________ from the expansion joint and the second one should be __________ from the expansion joint.
4 pipe diameters
14 pipe diameters
It travels through the centreline of the expansion device. All mechanical expansion joints are designed for __________, and within that group some will tolerate some deflection.
Axial Movement.
It is when the expansion joint acts as an offset device, with the faces of the fitting staying square to each other. The offset is measured in inches or millimeters.
Lateral offset
It is when the expansion joint acts as an offset fitting. The fitting will not have its faces square to each other, but one end will have turned or deflected. This deflection is measured in degrees.
Angular Rotation
If a considerable amount of joint lateral movement and offset is needed, then a ________ is the better device to use.
Flexible connector.
What is the primary purpose of a heating system?
To provide comfort to the individual in the space.
Heat always travels in which direction?
From warm objects to cooler objects.
What is not considered when calculating heat loss?
Interior walls of the building.
ODT is an acronym for which of the following?
Outdoor design temperature
To what does the designed temperature difference refer?
The indoor temperature minus the outdoor temperature
What is the recommended practice for determining room dimensions?
Measurements should be rounded up or down to the nearest .025 of a foot.
Which type of heat loss results in cool air from the outside being drawn into the building through cracks around windows, doors and loose construction?
Infiltration losses
Which of the following heat loss types transfer heat through a ceiling?
Transmission losses
What must be known in order to properly size a boiler?
Total net heat loss of the space being heated.
What causes frequent cycling of a boiler?
A boiler with an output that is too high for the application.
What procedure should be followed to ensure proper boiler start-up?
Boiler manufacturer.
What is the safest way to check for gas leaks prior to firing the boiler?
Soapy water solution
Flow rate, temperature drop and pressure drop are used to size which of the following?
Size of the piping
What must be known in order to properly size the output of a pump for a hydronic heating system?
Required gpm and total feet of head
What is the main function of an expansion-handling device?
To allow the water in the system to expand and contract as the system water heats and cools.
How do diaphragm tanks differ from standard closed expansion tanks?
Diaphragm tanks have a bladder that separates the water and air.
In which section of the heating code will you find definitions?
Section 3
Quality of work is referenced in which section of the heating code?
Section 4
Which section in the heating code deals with hydronic space heating?
Section 13
What is covered in Section 15 of the heating code?
Auxiliary systems
What must be selected prior to installing rough-in piping?
Heat transfer units
When you calculate heat loss through a concrete wall, you use?
K value
When you calculate heat loss through a wall made of many materials, you use?
U value
When you compare the resistance to heat loss of various insulation materials, you use?
R value
1/R=?
U value
To calculate the R value of a wall, you would _____ the R values of each material.
Add
If you wanted to increase the R value of a wall by R50, it would take about?
8 inches of Styrofoam.
A heat loss calculation for resistance is necessary to determine?
The output needed by a heating appliance to counteract building heat loss.
When calculating heat loss through a wall built of numerous material, the factor used is?
U value
When calculating heat loss through a wall built of a single material, the factor used is?
K value
R value is used to?
Show the resistance of various insulation materials to heat lost through them.
The heater should be located directly toward the source of cold air from a distance of ?
15-20 feet
Unit heaters should be located ?
6-12 feet above the floor
Convectors are manufactured in blank draft or blank draft styles
Natural or forced
Conventors range from _ inch or _ inch in length
16-72 “
Multi tear =
Fin vector
Modular panels are rated by
Btu output per panel
Linear radiant panels can be sized up to ?
You have to use insulation and conduction grease for expansion and contraction
16 feet
Series loop you loose heat the ?
Farther it goes ! To much pressure loss
Blow through unit heater is the same as?
Horizontal unit heater 12f
A draw through heater is also known as ?
Vertical unit heater
Blow through unit heater the fan is located ?
Behind the coil forcing the air to be heated through the coil. Typically located in warehouse or commercial buildings
A draw through heater is located ?
Ahead of the coil, drawing or pulling the air to be heated through the coil. These are found in entryways into building
