Unit 11 Building Environmental Systems

Question 1

Furnace heat exchangers should be checked for corrosion because:
Select one:
a. Carbon monoxide could leak into the building
b. Cold air could leak into the building
c. The air will become too dry for comfort
d. Too much air could enter the furnace

Answer 1

a. Carbon monoxide could leak into the building

Question 2

In newer steam heating systems, the condensate discharged by the steam traps drains by gravity through the return piping to: 
Select one:
a. The boiler 
b. A condensate tank  
c. A combination feeder/cut-off control.
d. A deaerator

Answer 2

a. Allow for drainage of condensate

Question 3

Which two dampers operate together in an HVAC system?

Select one:

a. fresh air, exhaust air
b. fresh air, return air
c. return air, mixed air
d. return air, exhaust air

Answer 3

a. fresh air, exhaust air

Question 4

What is the generally accepted minimum amount of fresh air to satisfy human comfort and health?

Select one:

a. 25%
b. 5%
c. 15%
d. 10%

Answer 4

c. 15%

Question 5

What is an indicator of excessively high building static pressure?

Select one:

a. Occupants may get headaches
b. Doors that open to the outside may be difficult to open.
c. Kitchen and washroom exhaust fans will not ventilate correctly
d. Doors that open to the outside may stay open, or be difficult to close.

Answer 5

d. Doors that open to the outside may stay open, or be difficult to close.

Question 6

All supply and drain lines of a steam heating system must be pitched to:
Select one:
a. Allow for drainage of condensate
b. Allow collection of air at the highest points
c. Prevent corrosion
d. Allow for thermal expansion

Answer 6

a. Allow for drainage of condensate

Question 7

What kind of water is used in a clean steam humidification system?

Select one:

a. raw water
b. soft water
c. Demineralized water
d. potable water

Answer 7

c. Demineralized water

Question 8

Which of these statements about hydronic heat pumps is TRUE?
Select one:
a. Hydronic heat pump systems discharge heat to the outdoors during the cooling mode.
b. A single heat pump can provide simultaneous heating and cooling to several independent zones.
c. On hot days, when the cooling load is high, the heat recovered from the zones can reduce the firing rate of the hot water boiler.
d. Hydronic heat pump systems cannot provide ventilation air.

Answer 8

a. Hydronic heat pump systems discharge heat to the outdoors during the cooling mode.

Question 9

Two methods of calculating air infiltration into a building are the: 
Select one:
a. Crack and attrition method 
b. Air change and solar method  
c. Crack and conduction method  
d. Air change and crack method

Answer 9

d. Air change and crack method

Question 10

The level in the condensate receiver may be automatically controlled by a: 
Select one:
a. Float switch  
b. Pressure reducing valve 
c. Gate valve 
d. Drain valve

Answer 10

a. Float switch

Question 11

One of the advantages of the radiant panel hot water heating system over the conventional heating system is:
Select one:
a. Radiant panel heating systems require less piping
b. Radiant panel heating systems provide less resistance to water flow
c. Radiant panel systems are lower in cost
d. Radiant heat panels distribute heat more evenly throughout the room

Answer 11

d. Radiant heat panels distribute heat more evenly throughout the room

Question 12

Which of the following air handling systems is NOT suitable for providing cooling simultaneously to several distinct locations in a building?
Select one:
a. A roof top unit
b. A dual duct system
c. A high velocity terminal reheat system
d. A multi-zone system

Answer 12

a. A roof top unit

Question 13

A \_\_\_\_\_\_\_\_ is a fired heater installed where the heat is needed, that heats the air directly without the use of any ducting.
Select one:
a. Unit heater  
b. Unit ventilator 
c. Convector 
d. Rooftop uni

Answer 13

a. Unit heater

Question 14

When air is forced through a heating unit that contains both a fan and a coil, the unit is called: 
Select one:
a. A unit heater  
b. An induction unit 
c. A unit ventilator 
d. A convector

Answer 14

a. A unit heater

Question 15

A radiator valve is used to control the amount of: 
Select one:
a. Air leaving the radiator. 
b. Condensate leaving the radiator. 
c. Steam leaving the radiator. 
d. Steam entering the radiator.

Answer 15

d. Steam entering the radiator.

Question 16

The flow of water in a multi-zone hot water heating system is controlled by:
Select one:
a. Diverter fittings
b. Balancing valves
c. A circulating pump for each heating zone
d. Induction coils in each heating zone

Answer 16

c. A circulating pump for each heating zone

Question 17

Heat lost from a building is: 
Select one:
a. Independent of indoor air temperature 
b. Greater on windier days  
c. Independent of outside temperature 
d. Dependent on barometric pressure

Answer 17

b. Greater on windier days

Question 18

Which of the following statement about constant air volume systems with perimeter heating is FALSE?
Select one:
a. Constant air volume systems with perimeter heating are well suited for larger buildings, due to the space available for the low velocity ductwork.
b. Interior zones may use reheat coils in the supply air ducts.
c. The exterior wall convectors supplement the heat in the supply air, which is kept near 12.5°C
d. Excessive room cooling can occur with the 12.5°C air supply

Answer 18

a. Constant air volume systems with perimeter heating are well suited for larger buildings, due to the space available for the low velocity ductwork.

Question 19

Air can be removed from steam heating systems by installing: 
Select one:
a. Air vents  
b. Diverter fittings 
c. Air separators 
d. Dip tubes

Answer 19

a. Air vents

Question 20

The packless radiator valve has a bronze diaphragm that completely seals off the valve body, to prevent:
Select one:
a. Air from entering the radiator
b. Air leaking out around the valve stem
c. Steam leaking out around the valve stem
d. Differential pressure from changing the valve setting

Answer 20

c. Steam leaking out around the valve stem

Question 21

Infrared heaters are used in: 
Select one:
a. Theaters 
b. Lecture halls 
c. Libraries 
d. Skating rinks

Answer 21

d. Skating rinks

Question 22

Heat load from people in a room is mostly affected by: 
Select one:
a. The age of the people 
b. The number of people  
c. The activity of the people 
d. The building occupancy class

Answer 22

c. The activity of the people

Question 23

Thermal conductivity (λ) is the:
Select one:
a. Quantity of heat flow per unit time (in Watts)
b. Conductive heat transfer through a unit thickness of a single uniform type of material
c. Heat transfer through a one-metre cross-sectional area of a uniform material, in W/m2K
d. Reciprocal of the U-factor.

Answer 23

b. Conductive heat transfer through a unit thickness of a single uniform type of material

Question 24

In a radiant heating system, the maximum surface temperature of the walls is:
Select one:
a. 20°C
b. 38°C
c. 45°C
d. limited to 120°C in accordance with ASME IV

Answer 24

b. 38°C

Question 25

One of the disadvantages of forced warm air heating systems is the: Select one: a. Installation and maintenance costs are higher than steam heating systems b. Air contains too much moisture c. System can be quite noisy in comparison to gravity warm air heating systems d. High cost for the system due to specialty equipment required

Answer 25

c. System can be quite noisy in comparison to gravity warm air heating systems

Question 26

One of the advantages of hot water heating compared to steam heating is: Select one: a. Hot water boilers are more fuel efficient b. Hot water systems have lower maintenance costs c. Hot water systems do not require water treatment d. Constant radiator temperature is easier to maintain in a hot water system

Answer 26

b. Hot water systems have lower maintenance costs

Question 27

``` Of the following, which is a method of indirect electric heat? Select one: a. Electric boilers b. Radiant panel heaters c. Wall heaters d. Unit heaters ```

Answer 27

a. Electric boilers

Question 28

What is the target Relative Humidity (RH) for a building in the summer, when the supply air temperature is 18°C? Select one: a. 30 to 50% RH b. 50 to 70% RH c. 40 to 60% RH d. 20 to 30% RH

Answer 28

c. 40 to 60% RH

Question 29

``` In a hot water heating system, air separators should be installed in: Select one: a. horizontal lengths of pipe b. vertical pipes c. expansion tanks d. hot water converters ```

Answer 29

a. horizontal lengths of pipe

Question 30

Thermal resistance (R) is the: Select one: a. Quantity of heat flow per unit time (in Watts) b. Heat transfer through a one-metre cross-sectional area of a particular material with defined surfaces (W/m2°C) c. Heat flow per unit time through one square metre of a material, when exposed to a differential temperature of 1 degree Celsius (W/m2°C) d. Reciprocal of thermal conductance.

Answer 30

d. Reciprocal of thermal conductance.

Question 31

In unoccupied mode, or "off hours" mode, what is the winter control strategy? Select one: a. Fans stay running, OA and EA dampers modulate to minimum, RA dampers modulate to meet OA/EA b. Fans run normally, OA and EA dampers close, RA damper opens c. Fans shut down, OA and EA dampers close, RA dampers open d. Fans shut down, OA and EA dampers open, RA dampers close

Answer 31

c. Fans shut down, OA and EA dampers close, RA dampers open

Question 32

When air-handling units use hot water heating coils, energy can be saved by: Select one: a. Shutting of the hot water circulating pump when the air temperature set point is reached. b. Switching over to electric heat when the outside air temperature drops excessively. c. Turning off the supply air fans when the air temperature set point is reached. d. Adjusting the hot water temperature set point according to the outside air temperature.

Answer 32

d. Adjusting the hot water temperature set point according to the outside air temperature.

Question 33

``` In a fin-coil heat exchanger, the heat exchanger is Select one: a. a steam or hot water coil b. Gas-fired c. Oil-fired d. Direct-fired ```

Answer 33

a. a steam or hot water coil

Question 34

``` When starting up a steam heating boiler, it should be filled to: Select one: a. The maximum level b. Just above the LWCO cut in point c. 1/2 of the gauge glass d. The bottom of the gauge glass ```

Answer 34

b. Just above the LWCO cut in point

Question 35

``` In hot water heating systems with closed expansion tanks, ___________ valves automatically fill and pressurize the system. Select one: a. Feedwater control b. Pressure relief c. Expansion d. Pressure reducing ```

Answer 35

d. Pressure reducing

Question 36

Heat is lost from a building in the following ways: Select one: a. Convection, evaporation, and radiation b. Evaporation, conduction, and radiation c. Conduction, radiation, and convection d. Infiltration, evaporation, and convection

Answer 36

c. Conduction, radiation, and convection

Question 37

Which one of the following statements about central air conditioning systems is FALSE? Select one: a. Unitary systems can control noise and vibration better than central systems b. All the major equipment in central systems is located in a central mechanical room in the building. c. The central system is able to utilize large central equipment with high efficiency and low initial cost. d. Central systems are used in large buildings.

Answer 37

a. Unitary systems can control noise and vibration better than central systems

Question 38

The ventilation rate of a building is determined based upon the greater of the Select one: a. Solar heat rate and CFM rate per person b. Conduction rate per person and solar heat rate c. CFM rate and conduction rate per person d. Infiltration rate and CFM rate per person

Answer 38

d. Infiltration rate and CFM rate per person

Question 39

Thermal transmission is the: Select one: a. The total heat flow due to all heat transfer modes, per unit time (in Watts) b. Ability of a material of uniform thickness to transmit heat (W/m°C) c. Same as thermal conductance. d. Thermal energy flow, by conduction only, through a unit thickness of a single uniform type of material.

Answer 39

a. The total heat flow due to all heat transfer modes, per unit time (in Watts)

Question 40

In extremely cold climates, it may be necessary to _________________________ in an HVAC system. Select one: a. Close the outdoor air dampers b. Install two separate pre-heat coils c. Heat the dampers d. Spray warm glycol on the hot water coils

Answer 40

b. Install two separate pre-heat coils