Hydronic Self Test Questions

Question 1

What are the 5 types of heat loss?

Answer 1

1) Radiation
2) Evaporation
3) Convection
4) Conduction
5) Respiration (so min doesn’t count)

Question 2

What is the approx.. % of heat that a human body loses by radiation?

Answer 2

48%

Question 3

What is the phenomenon known as, where a person can feel cold b/c they are sitting too close to a window or exterior door, when the temperature setting in the room is normal?

Answer 3

Cold 70

Question 4

What is the name given to the set of interior room temperature conditions where the human body feels the most comfort?

Answer 4

The ideal heat curve

Question 5

What is the temp that is read on a thermometer indicating?

Answer 5

The intensity of a heat present

Question 6

What is the formula when calculating the BTUs involved in heating of water within a heating plant (ex: boiler)

Answer 6

BTUs = Mass x temp diff x S.H

Question 7

What is the temp differential used in the design of most hot water heating systems that are fed from a boiler?

Answer 7

20 F

Question 8

What is the min return water temp that should be maintained when using a non-condensing boiler?

Answer 8

140 F

Question 9

What is the term known as, where heat is able to be applied to only the areas of a building where it is needed, rather than to the whole building?

Answer 9

Zoning

Question 10

What would the K value for a material that has an insulating value of R = 22?

Answer 10

0.045 (1 divided by 22)

Question 11

When designing a heating system, what is the January 2.5% value for the geographical area known as?

Answer 11

The Outdoor Design Temp

Question 12

What is the allowable IDT that can be used residentially when performing a heat loss estimate if hydronic radiant panels are intended as the primary source of heat?

Answer 12

68 F

Question 13

What is the allowable IDT for an unfinished basement?

Answer 13

18 C –> 64 F

Question 14

In heat loss language, what is the term for heat that is lost from a building through conduction?

Answer 14

Transmission

Question 15

What is the term for heat that is lost when cold air makes its way into the building through cracks / imperfections in the buildings envelope?

Answer 15

Infiltration

Question 16

What would give a double - glazed window the best insulation rating?

Answer 16

Low “E” - Argon filled

Question 17

What is the term given to the situation where, a heated slab-on-grade butts up to the exterior foundation wall, allowing heat to transfer between the two materials more easily than through the surround structure?

Answer 17

Thermal bridging

Question 18

What would be the expected outcome of the rate of heat transfer if the temp diff. between two sides of a wall or ceiling were doubled?

Answer 18

The rate would double

Question 19

What would be the expected outcome of the rate of heat transfer if the “R” value of a material were doubled?

Answer 19

The rate would be halved

Question 20

How many air changes / hour (ACH) would a room with openings on 3 sides undergo?

Answer 20

1

Question 21

What is the “R” value of 3” of extruded polystyrene?

Answer 21

15.0 (3 x 5.0 / inch)

Question 22

Which variety of PeX tubing is manufactured by the Engel method / has a memory?

Answer 22

PeX A

Question 23

Which variety of PeX tubing requires an oxygen - diffusion barrier when used in radiant floor panels?

Answer 23

PeX A, B, C

Question 24

What min thickness of rigid polystyrene foam should be placed under a basement concrete slab that is heated by radiant mean?

Answer 24

2 1/2”

Question 25

If a repair connection must be installed in a loop in a concrete over wood subfloor panel, where should the joint be located?

Answer 25

In the ceiling below

Question 26

What is the purpose of the wide, extra bottom plate in above grade walls of a radiant floor panel system?

Answer 26

1) to allow for carpet nailing strips 2) Act as screed for the second concrete lift 3) to make up 1 1/2" of ceiling height that the concrete takes from the room

Question 27

What takes the place of a boiler in a snow melt system / effectively separates it from the building's heating system to prevent the entire system from having to be freeze protected?

Answer 27

A heat exchanger

Question 28

What are radiant floor systems known as that heat the joist space below a floor?

Answer 28

Dry systems

Question 29

What is installed along with batt insulation between joists that causes heat to be driven upward instead of downward?

Answer 29

Reflective foil

Question 30

Does radiant ceiling panels operate at low temps?

Answer 30

No, at high temps

Question 31

How would you lay radiant tubing loops in rooms that have 1 or 2 outside walls?

Answer 31

first pass = 6" from outside wall turn 180 another 6" pass resume normal loop layout

Question 32

What is the max floor output from a radiant panel, in areas where people spend much time, over which supplemental heat will be necessary?

Answer 32

40 BTUH / ft2

Question 33

What is generally the longest suggested loop length for 1/2" radiant tubing at a 20 degree pressure diff.

Answer 33

300 feet

Question 34

What is normally used to locate tubing operating and embedded in a residential concrete floor?

Answer 34

an infra-red thermometer

Question 35

Which multiplier would be used when determining the total tube required for a room with tubing laid at 6" O.C spacing

Answer 35

2:1

Question 36

To what pressure / for how long should tubing be tested before being poured into a concrete mass?

Answer 36

100 psi / 30 min

Question 37

What is the main characteristic of a boiler is used when choosing it?

Answer 37

its output

Question 38

When assigning a head loss to a circulator, what is used as the head loss for the piping?

Answer 38

The single circuit w/ the highest head loss served by the pump

Question 39

What are the 2 variables that are used in choosing a circulator?

Answer 39

Flow rate and feet of head

Question 40

How many millinches are there in one foot?

Answer 40

12,000

Question 41

What variety of valve is a circuit setter?

Answer 41

Globe

Question 42

What is the name given to the strategy that uses a motorized mixing valve to automatically adjust its temp setting in reaction to changing outdoor or system thermal conditions?

Answer 42

Reset control

Question 43

What is the term given to the practice of ensuring that the operation of one pump doesn't affect the operation of another, if they share common piping?

Answer 43

Hydraulic separation

Question 44

What characteristic of a brazed plate heat exchanger accounts for its high rate of heat transfer?

Answer 44

It's inner plate surface area

Question 45

What type of valve can be installed between the supply / return mains that will open when the pressure in the supply main gets too high, as might happen when only one or two zone valves are open and there is only one system pump?

Answer 45

A differential bypass valve

Question 46

If 2 pumps are installed in parallel with each other, the approximate what will double?

Answer 46

Flow rate

Question 47

What is the moving part of a switch known as?

Answer 47

The pole

Question 48

What is the stationary part of a switch known as?

Answer 48

Throw

Question 49

How are switches designated?

Answer 49

By their number of poles / throws

Question 50

What type of switch only makes while a person is pushing or twisting it?

Answer 50

A momentary switch

Question 51

What most accurately describes a heating thermostat?

Answer 51

Open on the rise

Question 52

What are switches called that react to water temp?

Answer 52

Aquastat

Question 53

What is this a picture of?

Answer 53

A pressure switch

Question 54

What is the name of the switch that is used in a zone valve to prove that the valve is open?

Answer 54

An end switch

Question 55

What voltage is applied to the two yellow wires of most zone valves?

Answer 55

24V AC

Question 56

What voltage value is applied to the two red wires of most zone valves?

Answer 56

24V AC

Question 57

In which leg of a circuit should switches be located?

Answer 57

Hot leg

Question 58

What type of relay is most often found in use in hydronic heating systems

Answer 58

EMR

Question 59

What is the voltage value of the coil in most relays used in hydronic heating control circuits?

Answer 59

24V AC

Question 60

What voltage value do most pumps in hydronic systems use?

Answer 60

120V AC

Question 61

What is this picture?

Answer 61

A low water cutoff

Question 62

In the bottom right corner, what is it?

Answer 62

A pressure switch

Question 63

Which type of relay has no moving parts but usually only controls one device?

Answer 63

an SSR

Question 64

What is used to "scrub" latent heat from a condensing boiler?

Answer 64

A secondary heat exchanger

Question 65

What is the principle behind the use of multiple pumps for proper flow rates in a primary/secondary piping system?

Answer 65

Hydraulic separation

Question 66

Tees in a primary / secondary system should be placed no father than a max of --- diameters apart

Answer 66

4

Question 67

One USGPM will deliver --- BTUH if the temp differential is 20F

Answer 67

10,000

Question 68

What device, contained within a 4-wire zone valve, ensures that the pump won't start / the burner won't fire unless the zone vale is open?

Answer 68

An end switch

Question 69

What term is sometimes given to a low-mass boiler?

Answer 69

Cold start

Question 70

What is the main feature of a ladder diagram that makes it easy to follow?

Answer 70

The lines that represent wires won't cross each other

Question 71

Where are the low voltage terminals located on a relay / transformer centre?

Answer 71

On the face of the transformer

Question 72

What terminal on a relay/ transformer center is the 24V AC neutral?

Answer 72

C terminal

Question 73

Which terminal on a relay/terminal center powers all the thermostats and end switches?

Answer 73

R terminal

Question 74

Which terminal(s) on a relay / transformer center would be wired to an AC system?

Answer 74

W and Y terminals

Question 75

Where in the piping would a 3- way mixing valve be located?

Answer 75

At the mixing point

Question 76

Where in the piping would a 3 way diverting valve be located?

Answer 76

In the boiler return piping

Question 77

What is the main advantage for using a 3-way diverting valve rather than a 3-way mixing valve?

Answer 77

A diverting valve has less head loss than a mixing valve

Question 78

What is one main disadvantage of using a 3-eay diverting valve rather than a 3-way mixing valve?

Answer 78

It needs a remote sensor

Question 79

How many inlets / outlets does a 3 - way diverting valve have?

Answer 79

1 inlet / 2 outlets

Question 80

What is the best option for tempering water to a low temp system due to its very low head loss?

Answer 80

a 4 way mixing valve

Question 81

What is the term given to a controller that automatically adjusts system water temp when the temp outside rises or falls?

Answer 81

Outdoor reset

Question 82

What is the setting known as where, on an outdoor reset control, the indoor and outdoor temp are equal, causing the system to shut itself off?

Answer 82

Warm Weather shutdown point (WWSD)

Question 83

What is the next event that occurs after a zone thermostat closes?

Answer 83

The zone valve opens

Question 84

What happens when 24 V AC is sent to "G" terminal on a primary relay / transformer center that is controlling a non- condensing boiler using a single pump? (G = Go for pumps/ burners)

Answer 84

The pump turns on and burner fires

Question 85

What is the normal temperature setting for an indirectly -fired domestic water heater?

Answer 85

140F

Question 86

How many contacts are needed on a secondary relay / transformer center to make the primary and secondary pumps start in a 2 temperature system?

Answer 86

two N.O contacts

Question 87

Looking at a ladder diagram, if you follow a path from the C terminal of a transformer backwards through the diagram, what will you find?

Answer 87

Loads

Question 88

In what arrangement and into which circuit are all the limit switches wired for a hydronic system that uses a gas boiler?

Answer 88

In series, in the burner circuit

Question 89

A Radiant floor panel must have a N.C high limit on the piping feeding it that must shut off the burner if the temp reaches ---F above its designed temp?

Answer 89

20

Question 90

If needed where would a BVSS be located on a boiler? (Block Vent Safety Switch)

Answer 90

Near the draft hood

Question 91

If a secondary transformer is necessary because of too much load, what will provide power for it?

Answer 91

Only the extra thermostats / zone valve motors

Question 92

What component of a hydronic heating system is wired to the priority terminals of a zone control board?

Answer 92

The DHW zone valve

Question 93

When the priority zone calls for heat, which other zones will still operate?

Answer 93

None

Question 94

A voltmeter will be connected ---- with the circuit or component being tested

Answer 94

In parallel

Question 95

an ammeter that isn't a clamp on style will be connected ---- with the circuit or component being tested

Answer 95

In series

Question 96

When checking amps on a 4 - wire cable, using a clamp on style ammeter, how many wires can be encircled by the meter's jaws?

Answer 96

1

Question 97

What is the single most important point when using an ohmmeter?

Answer 97

Make sure the circuit isn't powered

Question 98

What would be the next step involved after touching the leads together when "zoning" an ohmmeter?

Answer 98

Turn the adjusting screw so that the pointer is directly over the 0

Question 99

What is field wiring?

Answer 99

Wiring that is not factory installed

Question 100

What is the difference between "wire" and "cable"

Answer 100

Cable consists of individual wires

Question 101

What is the purpose of a split plastic bushing when used with armoured cable?

Answer 101

to prevent abrasion of the wire insulation

Question 102

What does CEC stand for?

Answer 102

Canadian Electrical Code

Question 103

What type of box must be used with metal conduit?

Answer 103

Metal

Question 104

If a device box can be dismantled / made larger, it is said to be?

Answer 104

Gang -able

Question 105

How are box entry fittings attached to boxes?

Answer 105

Through knockouts on the box wall

Question 106

Exposed conductors must be protected from damage if within --- of the floor

Answer 106

1.5m

Question 107

What is the difference between BX and Teck cable?

Answer 107

Teck is waterproof BX is not

Question 108

What is used to connect PVC conduit to a box?

Answer 108

a threaded adaptor

Question 109

What type of material is rigid metal conduit?

Answer 109

Galvanized schedule 40 pipe

Question 110

What is any rigid enclosed or semi-enclosed channel that protects, routes and hides cables / wires known as?

Answer 110

raceway

Question 111

What is the power output limitation for a class 2 circuit?

Answer 111

100 Watts

Question 112

What is the general rule regarding separation distance between low voltage / line voltage conductors that are in close proximity to each other?

Answer 112

Maintain at least 2 inches physical distance between them

Question 113

A "marrette" is an example of a --- of wire connector

Answer 113

Solderless

Question 114

How much length of tightly - twisted bare wire ends should there be under a wire nut connection?

Answer 114

5/8" -- 3/4"

Question 115

What device is suggested for use when connecting small diameter wires, to prevent them from breaking if twisted together?

Answer 115

A terminal strip

Question 116

How much wire must be stripped for a crimped connection?

Answer 116

1/4" -- 3/8"

Question 117

What must not be joined using a soldered connection?

Answer 117

Two bonding wires

Question 118

What is suggested to be used whenever making a soldered wire connection, to avoid melting the wire insulation?

Answer 118

A heat sink