Chapter 13 Mechanical and Electrical Systems

Question 1

What are HVAC all-air systems and all-water systems?

Answer 1

All- air systems: cool or heat a space by conditioned air transported to the space with supply and return air ducts

All-water systems: use some type of coil unit called a convector in each space through which hot l water is circulated. The hot water heats the fins of the coil unit which heats the air as it is drawn over from the fins.

Question 2

Where are ducts and plumbing run typically in residential and commercial construction?

Answer 2

Residential - walls and floor joists

Commercial - the plenum and chases

Question 3

What is a chase?

Answer 3

An enclosed vertical space used only to accommodate ducts or pipes, it will run continuously through floors on multistory buildings

Question 4

When a project is to retain an existing HVAC system, what needs to be considered when designing the ceiling?

Answer 4

Large ducts leave little room for recessed lighting

Question 5

What is a mixing box?

Answer 5

Mixing box located in the plenum adjusts the quantity or temperature of air going into a space from the main air supply line; reduces velocity of air and attenuates noise

Question 6

What is a variable air volume system? (Vav)

Answer 6

HVAC system that supplies air at varying levels or amounts at a constant temperature

Question 7

When thinking of a plenum consisting of layers, what is located at each level?

Answer 7

building structure (Uppermost level)
Ducts, mixing boxes, other hvac approx sixe of large rest duct under largest structural element
Sprinkler and plumbing approx 4”-6”
Recessed lighting (lowest level) approx 9”-12”

Question 8

What height are thermostats located?

Answer 8

48” AFF

Question 9

What are the minimum clearance of a window treatment with exterior glass? (Commerical)

Answer 9

1 1/2” min between window header and top of window treatment
1 1/2” min between window ledge and bottom of window treatment
2” min between glass and window treatment
1 1/2” min between wall and window treatment
ADD PIC PG. 13-6

Question 10

What are the three common types of air-supply diffusers?

Answer 10

In-lay diffuser ( inserted into suspended ceiling system)

Residential / gypsum air diffuser (uses trim flange that snaps onto diffuser and cover ceiling cut out

Slot diffuser (used when space is limited or appearance wants to be minimized

Question 11

On a HVAC plan, how are piping and ductwork represented?

Answer 11

With single lines

Question 12

What is a junction box?

Answer 12

Steel or approved plastic box to which the conduit or cable system is attached

Question 13

In residential construction, outlets must be placed no farther than______ ft apart

Answer 13

12 ft

Question 14

What are “dedicated circuits “?

Answer 14

Special power outlets placed on their own circuit to prevent various types of electrical interference from sensitive electrical equipment

Question 15

What are three types of protection provided in electrical wiring? Describe them.

Answer 15

Grounding: a separate wire in addition to the two that provide power which prevents a dangerous shock if someone touches an appliance with a short circuit and a ground path at the sense time.

Ground fault circuit interrupters (GFCI’s or GFI’s) : devices that detect small current leaks and disconnect the power to circut or appliance.

Arc-fault circuit interrupter(AFCI) :device that provides protection from the effects of arch faults by recognizing characteristics unique to arcing and functioning to de-engegize the circuit when this fault is detected

Question 16

What are the two major components of plumbing system?

Answer 16

water supply: cold and hot water supplied under pressure to individual plumbing fixtures

Drainage: sloped drain pipes which carry away waste through gravity. Comprised of vents, traps, stacks

Question 17

What is a trap, vent, and soil waste stack in a plumbing drainage system?

Answer 17

Trap: located at every fixture, catch and hold water to provide a seal that prevents gases from the sewage system from entering the building

Vent: pipes connected to the drainage system open to outside air allowing built-up sewage gases to escape and allow the pressure in the system to equalize

Soil /waste stacks:
soil stack carries human waste
waste stack carries all other waste.

Question 18

What is a wet column?

Answer 18

Usually at a structural column where hot water, cold water, and drainage risers are located for tenants to easily tap into.

Question 19

Fire protection in buildings is accomplished by?

Answer 19

Preventing fires
early fire detection and alarm
providing quick exiting
containing fire
suppressing the fire

Question 20

What is the basic idea of “compartmentation” in fire safety

Answer 20

Contain a fire and limit it’s spread both to allow occupants to escape and protect other parts of the building that are not initially subject to the fire.

Question 21

How is the spread of smoke during a fine contained?

Answer 21

Devices such as fire dampers, gaskets on fire doors, automatic closing fire doors seal opening in fire walls.

Question 22

What are the 4 basic types of fire detection devices? Now do they work?

Answer 22

Ionization detector -responds to products of combustion-ionized particles

Photoelectric detector - responds to smoke

Rise-of-tempeature detector- senses presence of heat

Flame detector- responds to infrared or ultraviolet radiation given off by flames

Question 23

What are the disadvantages of rise-of-temperature detectors and flame detectors?

Answer 23

They do not give early warning signs of soldering fires/smoke

Question 24

IBC states buildings over______ ft tall require sprinkler systems

Answer 24

75ft

Question 25

What styles are sprinkler heads available in?

Answer 25

Recessed: have a smooth cover that Falls away when fire is detected

upright: used with exposed plumbing in an unfinished ceiling

pendant: traditional type for finished ceilings, head extends few inches below ceiling

side wall: used in corridors and small rooms

Question 26

Local building codes refer to what standard for the design and install of fire sprinklers systems?

Answer 26

NFPA 13

Question 27

What are the 3 groups NFPA 13 classifies spaces relative to fire hazard?

Answer 27

Light, ordinary, and extra hazard

Question 28

What is a standpipe?

Answer 28

Pipes that run the height of a building and provide water outlets at each floor to which fire fighting noses can be connected.

Question 29

What are the 4 general classes of handheld fire extinguishers?

Answer 29

Type A: for ordinary combustion, contain water
Type B: for flammable liquids, contain smothering chemicals
Type C: for electric equipment, contain con-conductive agents
Type D: for combustible metals,

Question 30

What is a holognated agent?

Answer 30

A gas that chemically inhibits the spread of fire, Used for fire extinguishing where water might damage the contents of a room. Bad for environment

Question 31

Security devised from intrusion detection can be classified into what 3 types?

Answer 31

Perimeter protection-secures the entry points to a space or building

Area or room protection - devices sense when someone is in a room

Object protection - devices sense movement with individual objects

Question 32

What are common types of perimeter protection?

Answer 32

Magnetic contacts, glass break detection, window screens

Question 33

What is electronic surveillance? How can we provide security from this?

Answer 33

The interception of sound and electromagnetic signals with remote sensing devices

special rooms are required that have electromagnetic or radio frequency shielding

Question 34

What features on high-security lock sets are available to provide an additional level of security?

Answer 34

Key types that are difficult to duplicate
special tumbler mechanisms
long throw deadbolts

Question 35

What is an electronic lock benefit over a mechanical lock?

Answer 35

Electronic locks selectively control access better and can monitor who enters/exits and record date and time

Question 36

What are biometric security devices?

Answer 36

Devices the read biological features like retinas or fingerprints to give access to a space

Question 37

Fire Damper

Answer 37

a device in a duct that is designed to automatic close when certain increase of temp or detection of smoke occurs