Deck 40: Heating, Air-Conditioning, Ventilation, and Refrigeration

Question 1

Describe the types of electric heating systems.

Answer 1

Types of electrically heated systems include factory assembled panels that mount on walls or ceiling, fabrics and wall covering material containing resistance heating wires, and various types of electric resistance cables that may be embedded in concrete or laminated in drywall ceilings or in plaster.

Question 2

A(n) ____ is a machine that can heat or cool a building using forced air through ducts.

A) warm air furnace
B) air conditioner
C) cool air furnace
D) heat pump

Answer 2

D

Question 3

Describe the operation of a single-zone heating and cooling system.

Answer 3

Single-zone systems use one air handling unit (AHU) to supply an entire building or a portion of a building that is considered a single zone. The furnace and air handling unit can be installed outside of or within the space to be conditioned.  A return air duct system is used to extract used air from a space and recycle it through the system to re-condition it by cooling or heating. A small residence may be conditioned with a single zone system. Larger residences may use two or more heating and cooling sources with two or more single zone systems. It should be noted that this system supplies air at a constant rate. Therefore, room temperature is varied by changing the air temperature.

Question 4

Describe relative humidity.

Question 5

How are electronic air cleaner cells cleaned?

Question 6

A ____ system is a variation of the single-duct singlezone and the multizone systems.

A) reheat
B) dual duct
C) variable air volume
D) multizone

Question 7

Class ____ particle conveying ducts are those for highly abrasive particles in high concentration.

A) 2
B) 3
C) 4
D) 5

Question 8

____ systems provide heating and cooling supply to terminal units by running a heating supply pipe to each terminal.

A) Two-pipe
B) Three-pipe
C) Four-pipe
D) Six-pipe

Question 9

A ____ humidifier uses electric heaters to convert water to steam and then injects it into the airflow in the duct.

A) pan
B) bypass
C) self-contained steam
D) wetted drum

Question 10

Describe the different types of grille outlets.

Question 11

____ filters are made of porous, coarse fibers coated with an adhesive substance that captures particles in the air.

A) Dry-type extended surface air
B) Viscous impingement fibrous panel
C) Electrostatic precipitation
D) Combination air cleaner

Question 12

Describe an air-to-air heat pump.

Question 13

____ use the space between the floor and the ceiling as a plenum.

A) Air distribution ceilings
B) Ceiling diffusers
C) Slot diffusers
D) Air distribution diffusers

Question 14

Thermal ____ involves the transfer of heat by the circulation of heated air, gas, or liquid.

A) convection
B) conduction
C) radiation
D) latent heat

Question 15

A shell-and-coil ____ has a coil of pipes within a shell or container.

A) heat exchanger
B) centrifugal chiller
C) air-cooled refrigerant condenser
D) cooling tower

Question 16

Describe hydronic controls.

Question 17

____ is a combustible hydrocarbon gas consisting primarily of methane with small amounts of ethane and traces of butane, propane, pentane, and hexane.

A) Fuel oil
B) Solid waste
C) Natural gas
D) Geothermal energy

Question 18

Describe steel boilers and how they are made.

Question 19

Define the terms sensible heat and latent heat.

Question 20

Describe the use of electricity as an operating source for HVACs.