03 Flashcards
Cleanout
A cleanout is a place in a sewer line where access can be gained to clear out clogs.
Tank Toilets vs. Tankless
Tank toilets are gravity-powered. Tankless toilets are powered by water pressure and can be reflushed more quickly than a tank style toilet.
Flushometer
Flushometers are a type of flush valve. They can be manual (lever), pushbutton, or touchless, activated by a sensor.
Flush Valve
Flush valves control the release of water into a toilet.
One-Line Diagram
A map of the electrical power flow between entities of a power system. Includes elements such as circuit breakers, transformers, capacitors, bus bars, and conductors shown as symbols. It is not drawn to scale, and the location and physical size of the elements is not shown.
Ice Storage Cooling
Ice is made at night, when temperatures are cool and energy demand is low, and used throughout the day to cool the building.
Oil Interceptor
Used in drain lines where wastewater may contain oil, the interceptor collects contaminants such as oil and allows for it to be stored and disposed of, instead of entering the sewer system. Used in parking garages, service stations, and manufacturing locations, where oil could find its way into the wastewater. Other types of interceptors, or traps as they are often called, include sand and grease.
Continuous Loop Hot Water System
Keeps hot water hot by recirculating it through a closed loop system.
Specific Heat
The thermal storage capacity of a material.
Mean Radiant Temperature (MRT)
The angular-size-weighted temperature of the surrounding surfaces.
Reverse Osmosis
Water purification technology that forces water through a semipermeable barrier that cleans out contaminants based on size, shape, and charge. Reverse osmosis is used in desalination plants.
Radiant Barrier
A reflective layer, sometimes attached to sheathing or insulation, that blocks radiant heat.
Thermal Gradient
The temperature at any point within a wall is on a gradient from the inside temperature to the outside temperature.
ABS
Black plastic pipe used for drain, vent, and waste lines in plumbing.
PVC
White plastic pipe, used for cold-water distribution and drain, vent, and waste pipes in plumbing.
CPVC
Cream plastic pipe, used for hot and cold supply pipes in plumbing.
Check Valve
A valve that allows water to flow in one direction only, preventing backflow that could contaminate the supply.
Gate Valve
A valve that uses a metal wedge to cut off flow. When it is open, it has lower friction loss than other types of valves because there are no turns.
Water Hammer
Water hammer is the noise that comes from moving water stopping abruptly in pipes that then shake and make a rattling sound.
Vacuum Breaker
A device in a plumbing fixture that prevents siphonage; often found on hose bibs.
Shock Arrestor
A device in plumbing systems to absorb the shock that causes water hammer.
Backflow Preventer
Any device in a plumbing system that prevents sewage from reversing flow.
Pressure Regulator
Devices on plumbing fixtures to reduce pressure when the supply pressure is too great.
DWV
Drain, waste, and vent piping (DWV) is usually plastic or cast iron.
Fixture Unit (FU)
A unit of measure that can be used to determine the required size of plumbing drainage pipes based on average rate of discharge, time of operation, and frequency of use.
When the wet bulb temperature equals the dry bulb temperature, what occurs?
100% humidity.
Heat Recovery Ventilator
Uses an air-to-air heat exchanger to use warm exhaust air to preheat incoming fresh air into an HVAC system; heat is recuperated and energy costs are reduced.
Energy Recovery Ventilator
Same as a heat recovery ventilator, but with the added benefit of a humidity recovery system.
Make-Up Air
Air added to an HVAC system to replace air lost through ex-filtration.
Psychrometry
Air, moisture, and heat have complex interactions and psychrometry is the study of these interactions.
As air temperature rises, its capacity to hold moisture ______ (rises/falls).
Rises.
On a psychrometric chart, the saturation line at 100% relative humidity is also called the _______.
Dew point.
Hygroscopic
A material that is hygroscopic absorbs moisture from the environment.
Tolerable Humidity
Humans can tolerate 20% to 70% humidity, but 30% to 65% is ideal for human comfort.
Annual Fuel Utilization Efficiency (AFUE)
A measurement of the fuel used yearly by an individual furnace, displayed on all furnaces manufactured in the United States.
Lift (for Water, Plumbing Formula)
(total feet of height) / (2.31 psi/ft); 1 PSI will raise a column of water 2.31 feet.
Reduced Pressure Back-Flow Preventer
A valve assembly used to protect the potable water supply from contaminated water. The valve stops used/return water from the building from flowing back into the public water supply.
Typical Fixture Required PSI (Toilet, Shower, Bathtub Faucet, Hand-Wash Faucet, Washing Machine, Dishwasher)
Toilet: 25 psi, 3 to 5 gallons per flush
Shower: 12 psi, 3 gallons per minute
Bathtub faucet: 5 psi, 4 gallons per minute
Hand-wash faucet: 8 psi, 2.5 gallons per minute
Washing machine: 8 psi, approximately 40 gallons per load
Dishwasher: 8 psi, approximately 15 gallons per load
Required CFM per Person Depending on Program Type according to IMC 2015 (Auditoriums, Bars/Clubs, Art Classrooms, Lecture Classrooms, Computer Rooms [Without Printing], Dry Cleaners)
Auditoriums (150 people per 1000 sf): 5 CFM/person
Bars/clubs (100 people per 1000 sf): 7.5 CFM/person
Art classrooms (20 people per 1000 sf): 10 CFM/person
Lecture classrooms (65 people per 1000 sf): 7.5 CFM/person
Computer rooms (without printing) (4 people per 1000 sf): 5 CFM/person
Commercial dry cleaner (30 people per 1000 sf): 30 CFM/person
CFM
Cubic Feet per Hours units of ventilation (volume) x ACH (Air Changes per Hour)/(60 min/1 hr)
Cross section area of a duct formula
A = CFM/V.
Grounding
A type of safeguard to protect people from shock and systems from shorting out, grounding allows electrical current to find an easy path to the earth.
Three-Phase Transformer
Three circuits carry three alternating currents, which reach their peak current at different times. Allows for a greater variety of power output options. Three-phase power is 60 cycles / second (hertz), but in three phases that are staggered, so each phase cycles one-third of the time apart. This provides more constant power.
List four types of dampers.
- Fire Damper: automatically stops air flow when there is an increase in temperature to prevent the spread of fire
- Splitter Damper: used to send a certain amount of airflow down a duct
- Balancing: balances the flow of air, but does not shut off the air
- Motorized Control: a remote system that varies the airflow within an automated system, very efficient
List the advantages of insulating ductwork.
- Reduces heat gain
- Reduces heat loss
- Reduces noise
- Prevents the buildup of condensation
What are two ways to reduce the HVAC noise in a building?
- By using vibration isolators composed of springs or pads between the building foundation and mechanical equipment
- By creating a separate foundation for the mechanical equipment
What are three types of private on-site waste disposal systems?
- Sand Filters: collection drains carry effluent to a non-potable watercourse, used in areas with impervious soil; expensive compared to other systems
- Leaching Cesspools: naturally occurring bacteria in the cesspool convert the organic matter to liquid, then the effluent flows from the septic tank through porous conduits and is absorbed by the soil; inexpensive compared to other systems
- Subsoil Disposal Beds: effluent drains a minimum of 2’ below the water table
List the three major components that make up a building’s electrical power system.
- Loads: the required demand created by appliances, lights, and mechanical systems required for the project’s various programs
- Interior-Distribution Equipment: the conductors, raceways, subpanels, and submeters used to distribute the electricity
- Service-Entrance Equipment: the transformers, service disconnect, fuses, meters, and circuit breakers
How are central heating systems classified?
By the medium they use (steam, air, or water) and by the energy source they use (solar radiation, electricity, or liquid/solid fuels).
What is the minimum depth of an accessible lavatory?
17”
NEC
The National Electrical Code (NEC) is written by the NPFA and is used throughout the U.S.
Overhead Electrical Service
The majority of electrical service is overhead. It is usually less expensive.
Underground Electrical Service
Advantages include less clutter, high reliability, and long life; usually more expensive.
How long has electricity been used in buildings?
A little over 100 years. Thomas Edison opened direct current generating stations in London and New York in 1882. The White House got electricity in 1891.
Lightning Rod
A metal rod or wire on a building that diverts lightning to the ground.
The discovery of the relationship between magnetism and electricity allowed for which technologies?
Generators, motors, and transformers.
Electricity
Flow (current) of electrons from negative to positive charges. It is an invisible form of energy that can be transformed into other types of energy, like heat and mechanical energy.
True or false? Electric current always generates heat.
True.
Electrical Resistance
The measure of the difficulty of an electric current to pass through a conductor; measured in ohms.
Direct Current vs. Alternating Current
In direct current (DC), the voltage and current remain constant over time. In alternating current (AC), the voltage and current changes direction periodically. Batteries supply DC power. Electrical outlets in buildings provide AC.
Capacitors
Electrical devices that can correct the out-of-phase current of an inductor and raise the power factor.
Bus Bars
Metallic bars where power is concentrated for distribution to many wires. They can be found inside electrical panels.
Conductors
Any material that allows the flow of electricity: for example, a wire. Copper is a good conductor. The opposite of a conductor is an insulator. Most nonmetallic solids are insulators.
Ohm’s Law
States the relationship between current, voltage, and resistance. It states that current is directly proportional to voltage and inversely proportional to resistance, or current is equal to volts/resistance.
Static Electricity
Usually created by friction. It is usually harmless unless it sparks a flammable gas.
What is electromotive force and how is it measured?
Electromotive force is a difference in potential that gives rise to an electric current. It is measured in volts. It is analogous to intensity or pressure.
60 Cycles per Second
The frequency of alternating current (AC) in the U.S. It is measured in hertz.
Electromagnetic Induction
When an electric field is created by a changing magnetic field. This is a foundational concept for the way electric motors work.
Power Factor
Inductors throw currents out of phase, which reduces the power in the circuit. This effect is called power factor (PF) and is the ratio of real power to apparent power. Real power is the capacity of the circuit, and apparent power is volts x amps. The power factor is a value between -1 and 1. Capacitors can fix this negative effect.
Inductors
Electrical devices that use magnetic fields, like ballasts and motors.
Impedance
Inductors create an opposition to the current as well as resistance, and together they are called impedance. Impedance is measured in ohms.
Circuit
A path through which electricity flows from a source to one or more devices and then returns. Circuits are either in series (older Christmas lights) or parallel (almost all circuits in a building).
Amps
Unit of electric current.
Short Circuit
A short circuit is when a current flows through an alternative path of lower resistance than the normal circuit.
Power
The function of an electrical circuit is to provide power, or energy, for work. Measured in watts. 1 kilowatt = 1,000 watts.
Voltage Drop
The amount of voltage lost in a circuit due to impedance.
Unit of Electrical Energy
Measured in kilowatt-hours (kWh).
Electromagnetic Field
Invisible fields of energy that surround electrically charged objects.
What times of day, respectively, are the least and the most power being used in the U.S.?
Least: late at night/early morning
Most: hot summer, late afternoon
Demand Surcharge
When the utility company charges more for power consumed during high demand times.
Remote Switching
Utility companies can remotely switch the power to their customers’ air conditioner units off during peak times to save energy. In return, the customer gets less expensive electricity.
Sources of Electricity
Currently, most electricity is produced by large centralized power plants fueled by coal, oil, natural gas, nuclear, or hydroelectric energy. Increasingly, wind and solar farms are contributing to the electric energy supply.
Transformer
Converts voltage either up or down by electromagnetic induction. Overland electrical voltage is very high and is stepped down by substation transformers and again by transformers in buildings.
True or false? The greatest safety threat of electricity in buildings is electric shock.
False. It’s fire.
Blackout
A complete crash of the power grid due to the power demand exceeding the supply. A rolling blackout is one that is planned by the utility company.
Brownout
A temporary reduction in the available power in a community.
Rigid Body Concept
In statics, rigid body concept means to ignore the small deformations of a structural member when loaded, in order to greatly simplify calculations and reduce errors.
Slenderness Ratio
Slenderness is a measure of the propensity of a column to buckle under loading. The slenderness ration is given as l/r where l is effective length and r is radius of gyration. It has no units because it is a ratio.
Moment of Inertia
A measure of a material’s resistance to buckling and bending.
Stiffness
Resistance to deformation.
Plywood vs. OSB
Both plywood and oriented strand board (OSB) are structural wood sheets made by gluing pieces of wood together. These engineered wood products are generally interchangeable, but each has different qualities. OSB is made from wood strands that are glued together in a cross-oriented pattern. Plywood is made from thin plies of wood bonded together. OSB is less expensive than plywood. OSB can soak up water more readily, especially at the edges where it can swell and permanently deform. When plywood gets wet, it also swells but then returns to its original size when dry. OSB weighs more and is less stiff than plywood. OSB is stronger in shear. Both can offgas and may contain formaldehyde.
Gauge
A unit of measurement of the thickness of a material, for example, steel studs; counterintuitively, a smaller gauge number indicates thicker metal, and a larger gauge number indicates a thinner metal.
Cofferdam
A watertight enclosure that is built in a body of water to allow construction to occur, such as when building bridges. The cofferdam is built and the water is pumped out to create a dry working environment for construction.
In Situ
“In situ” means “in place.” It is used to describe concrete that has been cast in place as opposed to precast concrete cast away from the site.
Maximum size of aggregate in a concrete mixture
Limited by size of the section and spacing of the rebar.
ASD vs. LRFD
ASD is Allowable Stress Design. LRFD is Load and Resistance Factor Design and is also called Ultimate Strength Design. Both are ways to calculate stress and, therefore, choose structural members. ASD treats live load and dead load the same and applies a factor of safety at the end of a calculation. LRFD treats live loads and dead loads differently, with a factor of safety applied to each. ASD is the “old” way of doing things and LRFD is the “new” way, but they are very similar and yield similar results. ASD is simpler, while LRFD is more nuanced.
Moment
Rotational force. It is the same thing as torque. It is a product of force multiplied by distance.
Ponding
When water from rain or snow melt is retained on a flat or semi-flat roof and, under the additional weight, the roof deflects, forming a bowl shape that enables the roof to retain even more water, and so on.
Importance Factor
In calculating seismic and wind loads, importance factor is a multiplier assigned to a building based on the building’s use. Essential facilities like hospitals and fire stations have the highest importance factor.
Creep
When a material moves or deforms slowly over time due to mechanical stresses; may or may not lead to failure.
