Mech Elec 2 Final Exam

delivers potable water

Which of the following is NOT a characteristic of a sanitary drainage system?

to prevent contamination of potable water

What is the purpose of an air gap at plumbing fixtures?

lead solder

What did the EPA ban in 1986 due to its toxicity?

untested manmade chemicals in water

What is one of the biggest challenges in providing potable water today?

a porous underground layer that stores water

What is an aquifer?

water heater

Which component is NOT part of a rainwater harvesting system?

they are lighter and more corrosion resistant

Why are plastic rainwater storage tanks often preferred over galvanized tanks?

high energy and water waste

What is one disadvantage of centralized hot water systems?

solar water heaters

Which of the following is most energy efficient for water heating?

impervious urban surfaces

What type of terrain leads to flash floods and poor water absorption?

purple

What color is typically used for pipes that carry recycled or rainwater?

continuous hot water

What is the main advantage of a tankless water heater over a storage tank system?

they convert only 30% of the source energy to useful heat

Why are electric resistance water heaters considered unsustainable?

prevent unwanted heat loss through convection

What is the main function of a heat trap in hot water systems?

the collector is above the storage tank for natural convection

Which of the following is a key feature of passive solar hot water systems?

creating a tight thermal envelope

What is the first tier of the three-tier design approach for heating and cooling a building?

air-change method (ACH)

Which method is used to estimate infiltration rates in buildings?

greater reflectivity

what does a higher albedo indicate?

sphere

what is the most compact shape for extreme cold climates?

bedrooms

Which rooms should be placed on the north side of a building in thermal planning?

the energy crisis

What prompted widespread insulation use after 1973?

increasing costs with diminishing returns

What is a major limitation of simply doubling insulation thickness indefinitely?

inhalation of airborne fibers

What is the primary health hazard during fiberglass insulation installation?

acts as a fire stpp and does not release toxic gases

What makes Air Krete unique among foamed-in-place insulation?

reflect radiant heat

What is the function of radiant barriers?

edge heat losses

What is a major weakness of Vacuum-Insulated Panels (VIPs)?

inside the wall cavity

what location is preferred for insulation in steed-stud walls?

collar beams

What is the best insulation location for a sloped roof with a high ridge?

act as major heat bridges

What’s a thermal drawback of cantilevered balconies?

SIP (structural insulated panels)

What kind of panel system nearly eliminates heat bridges and allows quick erection?

switching logic and voltage selection

What aspect of the electrical system most directly impacts a building’s sustainability?

NFPA (National Fire Protection Association)

Who created the National Electrical Code (NEC)?

Fire

What was the main danger identified in early electrical systems?

Voltage can be stepped up or down easily

Why is alternating current preferred for long-distance transmission?

Loss reduces to 1/400 of the original

What happens to transmission energy losses when the current is reduced by a factor of 20?

A system that generates electricity and captures heat for hot water

What is cogeneration (CHP)?

Intermittency of power generation

What is a major downside of solar and wind power?

Electrolysis

What is used to store renewable energy as hydrogen?

Fuel cells

What devices convert hydrogen into electricity with only water as a byproduct?

service transformer

In small buildings, what steps down power from utility voltage to usable voltage?

Accessible areas like utility rooms or garages

Where is the electrical panel typically located in a small building?

Aesthetics and safety

Why are large buildings typically supplied with underground service?

Power measurement, distribution, and protection

What is the purpose of electrical switchgear?

An appliance that uses power even when turned off

What is a vampire load?

Greater adoption of low-energy design

What is a likely consequence of rising electricity costs?

Window overhangs and light shelves

What is a critical element for glare control in daylighting design?

Diffusing glazing

What type of glazing is recommended for skylights to control solar gain?

Sunlight can cause thermal and visual discomfort

Why is it important to distinguish between sunlight and daylight?

Ratio of indoor to outdoor illuminance under overcast skies

What does the Daylight Factor (DF) measure?

Increased potential for glare

What is the risk of setting the daylight factor too high?

Estimate daylight penetration from side windows

What is the purpose of the 2.5H rule?

First 15 ft can rely on daylight, 15–30 ft needs supplemental electric lighting

What does the 15/30 rule suggest about lighting zones?

Low SHGC and high VT

What kind of glazing is ideal for toplighting in hot climates?

Light shelves

What architectural feature is used in side lighting to enhance daylight penetration?

Light-colored and matte finishes

Which surfaces typically help reduce contrast and improve light distribution?

rough

What type of surface texture causes light to reflect in multiple directions?

Percentage of solar radiation transmitted through glass

What is the Solar Heat Gain Coefficient (SHGC)?

Outside glazing (external)

What is the most effective placement for shading devices to reduce heat gain?

Use electric lighting as a supplement to daylight

What is one recommended electric lighting strategy for sustainability?

Interference with daylight distribution

What problem can occur if light shelves are blocked by objects?

sheave

What mechanism is used to support traction elevator cables?

holeless

In which type of hydraulic elevator, are one or more telescoping pistons used on the side(s) of the cab?

Drilling the jackhole is expensive

Why are most hydraulic elevators not of the in-ground type?

hydraulic

Which is NOT a type of traction elevator?

Smaller motors that fit inside the shaft

What makes machine-room-less elevators more energy efficient?

traction

Which elevator type requires a penthouse machine room?

geaerless traction

What type of elevator is best for buildings over 300 ft (90 m) tall?

floor area required for shafts increases

What is the impact of taller buildings on elevator design?

grouping passengers by floors

What is “queue control” in elevator systems?

increase shaft capacity

What is the main advantage of double-deck elevators?

using gearless of MRL elevators

Which of the following contributes to elevator sustainability?

shut down some elevators during off-peak hours

What is one way to encourage elevator energy efficiency?

they become stairs

Why are escalators safer during a power outage?

museums and department stores

What kind of buildings benefit most from escalators?

prevent people from piling up

Why are escalator discharge areas important for safety?