Building Utilities: Lighting, Acoustics, Electrical, HVAC, and Fire Safety

Flashcards covering key vocabulary, definitions, and technical parameters for architectural lighting, architectural acoustics, electrical systems, HVAC, mechanical equipment, and fire safety.

Photometry

The branch of science that deals with the measurement of light intensity and luminous flux.

Candle Power

The unit of intensity of light emitted by one standard candle concentrated at a point.

Lumen

The SI unit of luminous flux, representing the total amount or rate of flow of visible light emitted from a source.

Illumination (E)

The density of luminous flux incident on a surface, calculated by the formula $E = \frac{I}{D^2}$, where $I$ is candle power and $D$ is distance in feet.

Visible Light Spectrum

The narrow band of the electromagnetic radiation spectrum visible to the human eye, ranging in wavelength from approximately $380\,nm$ to $750\,nm$.

Echo

The repetition of a sound produced by reflection from a surface, loud enough and delayed by more than about $0.05\,s$ relative to the direct sound to be perceived as distinct.

Reverberation Time (RT-60)

The time in seconds required for sound or reverberation in an enclosed space to decay by $60\,dB$ after the direct sound source stops.

Sabin

The standard unit of sound absorption equivalent to $1\,sq\,ft$ ($1\,ft^2$) of perfectly absorptive surface area.

Decibel (dB)

The logarithmic unit used to measure sound pressure levels and intensity relative to a reference threshold.

Noise Reduction Coefficient (NRC)

A standard rating representing the percentage efficiency of a acoustic material surface in absorbing incident sound energy.

Transient Sound

The direct sound wave that ceases immediately when the originating vibrating body stops vibrating.

Ampere

The unit of electric current representing the rate of flow of one coulomb ($6.25 \times 10^{18}$ electrons) per second through a conductor cross-section.

Volt

The unit of electric potential difference or electromotive force required to move a charge of one coulomb between two points.

Ohm's Law

A fundamental electrical law stating that current ($I$) in a direct-current circuit is directly proportional to voltage ($V$) and inversely proportional to resistance ($R$): $I = \frac{V}{R}$.

Branch Circuit

The portion of an electrical wiring system extending beyond the final overcurrent device protecting the circuit to the outlets served.

Service Entrance

The point of delivery and equipment (conductors, meter, and main disconnect) where electric power enters a building from the utility company.

Step-Down Transformer

An electrical transformer designed with more turns on the primary coil than on the secondary coil, transforming high voltage down to lower voltage for utilization.

Circuit Breaker

An overcurrent protection device equipped with thermal and magnetic trips that automatically interrupts a circuit under overload or short-circuit conditions and can be manually reset.

Ground Fault Circuit Interrupter (GFCI)

A safety device that continuously checks for amperage consistency between hot and neutral wires, instantly opening the circuit if a ground fault difference is detected.

Air Handling Unit (AHU)

Centralized mechanical HVAC equipment containing blowers, heating/cooling coils, air filters, and dampers to condition and distribute air throughout a building.

Ton of Refrigeration

A unit measuring cooling capacity equivalent to $12\,000\,BTU/h$ or $200\,BTU/min$.

Escalator

A continuous power-driven inclined stairway consisting of steps attached to a circulating belt, installed at an angle of inclination not exceeding $30^\circ$.

Elevator Hoistway

The fire-rated vertical enclosed shaft in a building providing travel space for an elevator car, counterweights, guide rails, and hoisting cables.

Building Automation System (BAS)

A centralized, computer-networked system designed to automatically control and monitor a facility's mechanical, electrical, HVAC, lighting, and security systems.

Class A Fire

A fire classification involving ordinary combustible solid materials such as wood, paper, cloth, rubber, and plastics, typically extinguished using water.

Flashover

The stage in a fire's development marked by a rapid transition from a localized fire to the near-simultaneous ignition of all exposed combustible items in an enclosure.

Fire Damper

An automatic closing closure installed in an air duct to restrict the passage of heat, flame, and smoke in the event of a fire.