Meh

Question 1

Types of valves and what they do and effects on fluids

Question 2

Filter definitions

Question 3

ASHRAE VS AHRI VS ABSA VS…

Answer 3

CSA & ABSA: B52-05
ASHRAE: flammability, toxicity,
Alberta Environment: administration of the Code of Practice
AHRI: determines refrigerant GWPs
National Office of Pollution 1996: Code of Practice

Question 4

Number meaning in Refrigeration numbers 🦀

Question 5

Entropy units

Answer 5

BTU/lb °R

Question 6

Temp rise, temp difference

Answer 6

(∆T) Temp rise/drop -> SST/SDT & ambient
(TD) Temp difference (diff mediums) -> ambient & cond/evap

Question 7

Def of work

Answer 7

Force * distance

Question 8

HCFCs, HFCs, HFOs, etc

Answer 8

HFOs: (new), r1234y,
HFCs: r23, r32, r134a, r404a, r410a, etc
HCFCs: r22, r123, r124,
CFCs: r12, 13,

Question 9

Spill vs rollout

Answer 9

Spill: interrupts the heating control circuit due to backdraft (hot flue gases spill out of the flue hood)
Rollout: Interrupts the heating cycle due to rollout (burner flame and flue gases remain the the burner compartment instead of heat exchanger)

Question 10

Forward curved vs backwards vs axial curved noise

Answer 10

Forward: quiet
Backwards:
Axial: noisy

Question 11

Flat blade

Answer 11

Medium air flow, low static pressure

Question 12

Curved airfoil

Answer 12

High airflow, high static pressure

Question 13

Radial tip

Answer 13

High air flow, medium static pressure

Question 14

400CFM/ton for ACs and 450CFM/ton for heat pumps
1ton = 700sqft

Question 18

PRV vs pressure relief vs pressure reducing, blowdown

Answer 18

PRV (pressure reducing valve) : limits the pressure for branch pressure use
Pressure relief valve: safety
Blowdown valve: Remove condensation from the receiver
Pressure controller: Starts and stops the motor to maintain receiver pressure

Question 19

Spring range

Answer 19

The range to produce total movement from one extreme position to another

Question 20

Pump down
Pump out

Answer 20

Pump down used on large built-up medium temp walk in coolers cuz of long lines
Pump out used on larger low temp to reduce short cycling

Question 21

Primary controller/control

Answer 21

Directly/indirectly controls the control agent

Question 22

Deviation
Offset

Answer 22

Deviation: length of time for control point and setpoint to equalize
or Difference between control point and setpoint at any instant
Offset: Sustained difference between control point and setpoint

Question 23

Line duty vs pilot duty

Answer 23

Line duty: interrupts the CURRENT directly to the motor
Pilot duty: interrupts a relay or something CURRENT that stops the motor

Question 24

Controlled device

Answer 24

Actuator/final control element/valve

Question 25

Controlled variable Manipulated variable Measured variable

Answer 25

Quantity or condition of the controlled medium Quantity or condition of the control agent

Question 26

Range Span

Answer 26

Difference between least and greatest values of a controller Difference between two limits

Question 27

Sulphur, regulator places names, specific density/volume,

Question 28

Pipe controller output to actuator vs input sensor pressure

Answer 28

Output to actuator: 0-20psi Input from sensor: 3-15psi

Question 29

remote bulbs are found in contact with _

Answer 29

controlled medium

Question 30

Usual NON ADJUSTABLE High limit setpoint

Answer 30

HL: 180F-220F

Question 31

Combination fan limit controller cut in and cut out temps

Answer 31

Cut out: 80-90F Cut in: 120-140F

Question 32

Low ambient limit controller temperature

Answer 32

50F (same as changeover temp 50-60F)

Question 33

Furnace limit controls

Question 34

Usual ADJUSTABLE high limit

Answer 34

HL: 150-200F

Question 35

Burnt open vs shorted

Answer 35

Shorted: over current

Question 36

Resistance, inductance, capacitance, reactance, impedance opposes what

Answer 36

Impedance: total opposition to flow of current Resistance: Limits amount of current Inductance: opposes change in current Capacitance: opposes change in voltage Reactance:

Question 37

Fuses protect

Answer 37

Conductor

Question 38

Air permeability

Answer 38

Air escaping from building

Question 39

6-10 duct diameter

Question 40

30° TD

Question 41

Hydrometer

Question 42

Schedules/specification book, section|page number

Question 43

Vernier