Download ARCH373 Design and Engineering of Environmental Systems Exam 2 Study Guide 2024-2025 and more Exams Systems Design in PDF only on Docsity!
ARCH373 Design and Engineering of Environmental
Systems Exam 2 Study Guide 2024- 2025 Verified
Question and Answer A+ Graded
Four goals of fire protection systems - ANS- Protection of life Protection of building Protection of contents Continuity of operation What event started the development of the NFPA 101 - ANS- The Triangle Shirtwaist Factory fire in 1911 fire trapped women and girls behind doors locked by management to prevent stealing. Many jumped out windows to escape and 148 people died What is the difference between thermal and non-thermal products from a fire? - ANS- Thermal= flame and heat Non-thermal= smoke and constituent gases Thermal products are visible and make tactile impressions Non-thermal pose the greatest threat to human life What is the fire triangle/tetrahedron - ANS- fuel, oxygen, heat energy, an uninhibited chain reaction the components it takes to produce a fire. If you take any one of these away, you cannot make a fire What is compartmentation - ANS- method of fire control passive system Each "compartment" of a building is enclosed by fire-rated walls, floors, doors, etc. one-hour separation is required between occupancies for a mix of occupancies within the same structure
What are smoke barriers? - ANS- method of smoke control passive system useful in a fire's early stages confines the initial layer of heated air and smoke produced by a fire helps slow the spread of smoke while making the early detection and suppression of the fire more likely What are dilution systems? - ANS- method of smoke control active system during the early stage of fire, dilution of smoke with 100% outdoor air (via HVAC system) may facilitate evacuation Beyond sort-term, dilution is rarely sufficient for smoke control What are exhaust systems? - ANS- method of smoke control active system single-purpose smoke exhaust system they employ both air velocity and air pressure to help control smoke movement As with dilution systems, high velocities are avoided so that fresh are is not drawn up through the smoke layer Such systems are particularly useful in large-volume atrium spaces requirements for exits and egress systems - ANS- need exit passageways in every building from every space more than 50 occupants= 2 or more exits stairs never less than 44 inches wide all doors swing in direction of egress panic hardware often required Different fire classes - ANS- Class A: can be extinguished with water Class B: burning gases and liquids can float on water, so it is less effective Class C: Extinguishing medium must be electrically non-conductive Class D: combustible metals requires special extinguishers
four types of sprinkler systems - ANS- wet system, dry system, preaction system, deluge system Wet Pipe Sprinkler System - ANS- simplest type- pattern of sprinkler heads with fusible plugs or links during fire- fusible element melts and water pressure causes spray Dry Pipe Sprinkler System - ANS- similar to a wet system except pipes are kept empty compressed air in pipes holds the dry pipe valve closed during a fire- fusible elements melt, and air depressurizes, water flows from warm enclosure Preaction sprinkler system - ANS- variation of the dry system- but requires activation of both the sprinkler head and an independent fire-sensing device this avoids accidental discharge of the system Deluge System - ANS- based on the idea that wetting an entire space is the safest way to extinguish a fire all of the sprinkler heads are open all of the time fire detection system activates the full release of water system is most common for spaces of high fire hazard What are the three basic factors of electricity (and plumbing analogues) - ANS- Potential (Volt, V): potential difference or electromotive force Current (ampere, I): rate of flow of electric charge in a circuit per unit of time Resistance (ohms, Ω or R): opposition of a conductor to the flow of current, causing some of the electricity to be transformed into heat Ohm's Law - ANS- I= V/R V= I x R R= V/I Relates voltage, current and resistance series resistance - ANS- effective total R is the sum of all of the resistances
parallel resistance - ANS- effective total resistance expressed by considering the different "flow paths" what is a circuit - ANS- the complete path of an electric current, including the source of electric energy Differences between AC and DC current - ANS- Direct Current (DC): the electrical current that flows in one direction constant voltage typical for low-voltage applications P= V x I Alternative current (AC): an electric current that reverses direction at regularly recurring intervals not as easy to calculate as with DC must incorporate a POWER FACTOR P= V x I x PF Typical HZ of United States electricity - ANS- 60 hertz difference between motor and generator - ANS- motor converts electrical energy into mechanical energy generator converts mechanical energy into electrical energy What is a transformer - ANS- A device that changes the voltage of an alternating circuit an iron core on which two separate coils of wire are wrapped Step-up transformers: increase voltage step-down transformers: decrease voltage oil insulated Transformer - ANS- contain flammable oil typically outdoors, if insides, must be installed in a fire-resistant vault, small size, low first cost, low losses, long life, low noise, high overload capacity
switchboard - ANS- switchboards are panels equipped with devices ready to reroute power as needed large, free-standing assembly of switches and fuses provides switching and protection to circuits connected to a single electric source distributes bulk power into smaller "packages" unit substation - ANS- an assembly, comprising a primary voltage switch-and-fuse or circuit breaker, a step-down transformer, meters, controls, bus work, and secondary (low-voltage) switchgear panel board - ANS- small scale switchboard accepts a large block of power and distributes it into smaller blocks final distribution point before branch circuits bus (busbar) - ANS- a heavy conductor, usually in the form of solid copper bar, used for collecting, carrying, and distributing large electric currents fuses - ANS- shutoff device device with soft metal links in a glass plug or fiber cartridge one-time use rated for current flow circuit breakers - ANS- shutoff device automatically disconnect a circuit when the current exceeds a certain amperage can be reset can be useful as a backup switch to shut off an area or specific circuit ground fault interrupter - ANS- detect a continual current lost to ground will break the current What is a conduit? Different types? - ANS- protection/insulation for wires Rigid Conduit (safest) Intermediate Metallic Conduit
Electrical Metallic Tubing Flexible Metal Conduit grounding - ANS- basic safety precaution connected to an element that can provide an electrical path to the ground or earth will dissipate any electric current with little to no resistance wires - ANS- standardized using American Wire Gauge 14 AMG is smallest used for building wiring copper is standard for branch circuits two-, three-, and four-way switches - ANS- Lights are often grouped into their own unique circuits that can be switched on and off from a central panel in commercial installations or from wall switches in residential installations One switch is a two‐way switch type. More than two switches require two three‐way switches and the remaining are four‐way switches. incandescent lamp (efficiency and lifespan) - ANS- typically rated for 2,000 hours output= 15-18 lumens per watt bulb containing a filament- typically a tungsten alloy that is heated with an electric current and glows fluorescent lamp (efficiency and lifespan) - ANS- typically rated for 10,000 hours output- 60 - 80 lumens per watt most are tubular, the inside surface of the tube is coated with fluorescent phosphors with an electric current, electrons flow between electrodes at each end HID lamp (efficiency and lifespan) - ANS- a lamp within a lamp- which runs at a very high voltage different types of HID lamps - ANS- Mercury vapor lamps: 24,000 hour life, 50 lumens per watt Metal halide lamps: 10,000 hour life, 80 lumens per watt High pressure sodium lamps: 24,000 hours, 85 lumens per watt typical (up to 110)
What is LID (low-impact development) - ANS- mimic natural hydrology in order to manage stormwater quality and runoff rates minimizes pavement and maximizes rainwater infiltration, filtering out pollution and preventing erosion constructed wetlands, rain gardens, bioswales, tree-planting boxes, permeable pavement, and green roofs What is green infrastructure? - ANS- uses vegetation, soils, and natural processes to manage water, and create healthier urban environments At city/county scale: refers to the patchwork of natural areas that provides habitat, flood protection, cleaner air, and cleaner water. At neighborhood/site scale: refers to stormwater management systems that mimic nature by soaking up and storing water. What is the Sustainable Sites Initiative (SITES) - ANS- a rating system that assesses the sustainable design, construction, and maintenance of landscapes modeled after and aligned with LEED reduce urban heat island, uses vegetation to minimize building energy use, reduce outdoor energy consumption, and use renewable sources for landscape electricity needs 200 point scale What is the Living Community Challenge (LCC) - ANS- regenerative design intent similar imperatives to LBC What are Ecodistricts - ANS- 3 broad categories: equity, resilience, climate protection thinking outside of the building transparency and knowledge-sharing What is the difference between "normally open" and "normally closed sensor types - ANS- Normally Open: no longer used because circuits are unsupervised defective circuit does not indicate trouble Normally Closed: operate to transmit an alarm signal
used in closed, supervised circuits, they provide a trouble signal when the sensors or circuits are damaged much more effective than NO Water-Energy Nexus - ANS- The relationship between how much water is used to generate and transmit energy, and how much energy it takes to collect, clean, move, store, and dispose of water. Different types of occupancy/security sensors - ANS- Mechanical Motion Detectors Photoelectric Devices Passive Infrared "Presence" Detectors Motion Detectors Acoustic Detectors Occupancy Sensors Carbon Dioxide sensors Mechanical Motion Detectors - ANS- If NC contacts are impractical, a mechanical motion detector can be utilized. Basically, a spring‐mounted contact suspended inside a second contact surface. Motion of the surface on which the device is placed causes the contacts to "make" momentarily ‐ turning in an alarm. Very sensitive and can be activated by sonic booms, wind, and even a heavy truck passing by. Thus, they exhibit a sensitivity adjustment. Photoelectric Devices - ANS- Operates on the simple principle of beam interruption. When the beam is received, a contact in the receiver is closed. Interruption of the beam causes the contact to open, setting off the alarm. Older devices of this design use a visible beam (light). Passive Infrared "Presence" Detectors - ANS- Operates on the principle that all objects emit IR radiation, or heat. The PIR sensor uses a lens or mirror that focuses on small coverage areas or zones. IR radiation in an area that is undisturbed changes slowly. Thus, rapid change in IR indicates an object entering (or leaving) - triggering sensor. Can be used as occupancy sensor.
space utilization optimization can analyze data and help decision-making on the utilization of a portfolio of buildings to: optimize the use of energy and optimize maintenance and operations what represents the opposition of a conductor to the flow of electrical current - ANS- Ohm LEED-ND addresses ____ - ANS- neighborhood development which lamp type has the lowest efficiency? - ANS- incandescent Which lamp type has the highest efficiency rate? - ANS- LEDs a high-pressure sodium lamp has a color temperature that is closest to _______ - ANS- candle light (2000 deg K) flexible metal conduit - ANS- cannot be used underground may have a flexible waterproof jacket "Flex" electric metallic tubing - ANS- thinnest of metal conduit no threaded connections "thin wall" rigid conduit - ANS- safest all connections are rigid and threaded same wall thickness as Schedule 40 plumbing pipe intermediate metallic conduit - ANS- steel conduit with thinner walls acceptable as a rigid conduit overhead transmission lines have voltage on what order of magnitude? - ANS- 100,000s of volts
One virtue of increased density in the design of urban environment - ANS- less per capita energy use
