Unit Review : Heating Systems & Human Comfort Comprehensive Self-Assessment Flashcards
1. The steam pressure on a steam grid humidifier should be in the range of: A. 20 kPa to 30 kPa (2.9 to 4.4 psi) B. 25 kPa to 45 kPa (3.6 to 6.5 psi) C. 40 kPa to 55 kPa (5.8 to 8 psi) D. 30 kPa to 60 kPa (4.4 to 8.7 psi) E. 35 kPa to 70 kPa (5.1 to 10.2 psi)
E. 35 kPa to 70 kPa (5.1 to 10.2 psi)
- A typical range for the pressure setting of an automatic fill valve (pressure reducing valve) in a hot water heating system is:
A. 50 to 100 kPa B. 80 to 103 kPa C. 100 to 200 kPa D. 103 to 125 kPa E. 125 to 150 kPa
D. 103 to 125 kPa
3. To determine the tension in a blowers driving belt, a force of about \_\_\_\_\_ should be applied. A. 25 N (5.6 pounds force) B. 30 N (6.7 pounds force) C. 45 N (10 pounds force) D. 75 N (17 pounds force) E. 20 N (4.5 pounds force)
C. 45 N (10 pounds force)
4. To avoid cavitation in the pump and drawing air into the system, a positive pressure at the highest point of the system should be maintained of at least: A. 100 kPa (14.5 psi) B. 76 kPa (11 psi) C. 52 kPa (7.5 psi) D. 20 kPa (2.9 psi) E. 12 kPa (1.7 psi)
E. 12 kPa (1.7 psi)
- To avoid cavitation in the pump the pressure at the highest point of the system should be at least equivalent to a head of water of:
A. 1.2 m (4 ft.)
B. 0.9 m (3 ft.)
C. 1.5 m (4.9 ft.)
D. 2 m (6.6 ft.)
E. 2.2 m (7.2 ft.)
A. 1.2 m (4 ft.)
6. The activated carbon will adsorb odour-causing gases up to about \_\_\_\_\_ of its own weight after which it has to be replaced. A. 5% B. 30% C. 15% D. 10% E. 20%
E. 20%
7. A room thermostat should be mounted on an inside about \_\_\_\_\_ above the floor and in the wall about path of natural air circulation when the heating system is off. A. 4.5 m (180 in) B. 1.5 m (60 in) C. 2.5 m (100 in) D. 3.5 m (140 in) E. 4.0 m (157 in
B. 1.5 m (60 in)
- The thermostat equipped with a coil-shaped bimetal element operating a mercury bulb switch is quite sensitive, having a temperature differential of less than:
A. 1°C (1.8°F) B. 2°C (3.6°F) C. 3°C (5.4°F) D. 5°C (9°F) E. 10°C (18°F)
A. 1°C (1.8°F)
9. Low pressure hot water heating installations are limited to less than \_\_\_\_\_ water pressure. A. 100 kPa (14.5 psi) B. 1000 kPa (145 psi) C. 206 kPa (30 psi) D. 500 kPa (73 psi) E. 103 kPa (15 psi)
C. 206 kPa (30 psi)
10. In the electronic filter dust particles are charged by passing the contaminated airflow through an ionizing zone formed by an arrangement of wires charged with \_\_\_\_\_ volts DC potential. A. 13 000 B. 15 000 C. 10 000 D. 12 000 E. 60 000
A. 13 000
11. In the electronic filter the collector plates are charged with \_\_\_\_\_ volts DC. A. 5000 B. 6000 C. 1000 D. 15 000 E. 13 000
B. 6000
12. Activated alumina chemisorbant is particularly suitable for the removal of: A. O2 B. N2 C. CO2 D. CO E. H2S
E. H2S
- The system of mechanical air intake, natural exhaust can supply fresh air in all of the following ways except:
A. By a propeller fan mounted in the outside wall
B. By installing a fresh air supply duct in a warm air heating system
C. By unit ventilators that draw in a controlled amount of outside air
D. By an exhaust fan mounted in the outside wall
E. By use of a makeup air heater
D. By an exhaust fan mounted in the outside wall
14. In all systems, the vertical pipes to the various floors are called the: A. Mains B. Risers C. Return lines D. Steam lines E. Steam pipes
B. Risers
15. One of the causes of insufficient steam supply to the heating units can be attributed to: A. Improper pitch restricting drainage B. Air vents passing air C. Valves on mains wide open D. Piping over sized restricting flow E. Bypassing of steam to supply line
A. Improper pitch restricting drainage
- When dealing with electrical controls transformer refers to:
A. A device used to change AC voltage from one value to another
B. A device consisting of a solenoid coil, which operates load carrying contacts when the coil is energized
C. A term that refers to the normal electric supply voltage
D. A term that refers to wiring or other electrical devices using 30 volts or less
E. The electric switch configuration of a relay
A. A device used to change AC voltage from one value to another
17. The Hartford loop prevents steam pressure from forcing boiler water back into the return line should the: A. Boiler pressure get to high B. Feedwater supply fail C. Check valve fail to close D. Water level get to high E. Boiler temperature be to high
C. Check valve fail to close
- The admission of fresh air into a room should be such that:
A. The air is spread over the floor area
B. Stagnant pockets of air are created
C. The air does not strike directly on the occupants
D. The air strikes directly on the occupants
E. The air is spread over the ceiling area
C. The air does not strike directly on the occupants
19. A warm air heating system consists of a centrally located heating furnace or heat exchanger an all except: A. A circulating pump B. A supply duct system C. A return duct system D. Supply outlets E. Return grilles
A. A circulating pump
20. From the plenum warm air flows into the \_\_\_\_\_ system which distributes the air. A. Register B. Return duct C. Grille D. Plenum E. Supply duct
E. Supply duct
- The piping and heating units of a steam heating system must be so arranged that:
A. Steam can flow freely from all heating units
B. Steam can flow in insufficient quantities to all heating units
C. The condensate can be returned freely to these units
D. The condensate can be returned freely to the boiler
E. The air can be contained in the heating units and piping
D. The condensate can be returned freely to the boiler
- One of the advantages of a forced warm air heating system is:
A. Temperature distribution is not uniform
B. The ducts can not be enclosed within walls and ceilings
C. The furnace must be located on the same floor
D. The air may be cleaned by filters.
E. The air can not be humidified
D. The air may be cleaned by filters.
- Thermal conductance (C) is the:
A. Thermal heat flow (transmission) through unit areas of a wall, door, window, etc., for every degree temperature difference between the air/fluid inside and the air/fluid outside. (W/m²K or W/m²°C) (Btu/hr/ft²R or Btu/hr/ft²°F)
B. Quantity of heat flow from all mechanisms, in unit time, under the conditions prevailing at that time (Q or W)
C. Thermal heat flow, by conduction only, through a unit area of a single uniform type of material (W/m°C) (Btu/hr/ft²°F)
D. Thermal heat flow through a unit area of a non-uniform, composite material when a unit average temperature difference is established between the surfaces (W/m²°C) (Btu/hr/ft²°F)
E. Reciprocal of thermal conductance, it is the value of a given material’s ability to resist heat transfer or flow (m²°C/W) (ft²°F/Btu/hr)
D. Thermal heat flow through a unit area of a non-uniform, composite material when a unit average temperature difference is established between the surfaces (W/m²°C) (Btu/hr/ft²°F)
- Thermal transmittance or U-factor (U) is the:
A. Thermal heat flow (transmission) through unit areas of a wall, door, window, etc., for every degree temperature difference between the air/fluid inside and the air/fluid outside. (W/m²K or W/m²°C) (Btu/hr/ft²R or Btu/hr/ft²°F)
B. Quantity of heat flow from all mechanisms, in unit time, under the conditions prevailing at that time (Q or W)
C. Thermal heat flow, by conduction only, through a unit area of a single uniform type of material (W/m°C) (Btu/hr/ft²°F)
D. Thermal heat flow through a unit area of a non-uniform, composite material when a unit average temperature difference is established between the surfaces (W/m²°C) (Btu/hr/ft²°F)
E. Reciprocal of thermal conductance, it is the value of a given material’s ability to resist heat transfer or flow (m²°C/W) (ft²°F/Btu/hr)
A. Thermal heat flow (transmission) through unit areas of a wall, door, window, etc., for every degree temperature difference between the air/fluid inside and the air/fluid outside. (W/m²K or W/m²°C) (Btu/hr/ft²R or Btu/hr/ft²°F)