Terms Flashcards
Anode
A piece of metal is often inserted in the water tank to divert the deposition rather than allowing it to form on the heat exchanger.
Friction loss
A function of the diameter of the pipe and the flow rate through it.
Soil stack
A large pipe into which all of the soil and waste lines from one or more levels empty Contains blackwater
Vent stacks
A smaller pipe that is the air intake line for all the fixtures, and that is also, separately, open to the outside air at the top. Does not have a stack below it
Stack vent
Vents the top of a soil stack and waste stack
Cleanout
A y-shaped segment of pipe which serves an area otherwise difficult to access, where one arm of the Y has a plug screwed in it at its end. They should occurs every 50 feet in pipes under 4 inches.
Swales
V-shaped sloping channels in the grass that take the surface runoff to points where it may be collected and or disposed of.
Catch Basin
Similar to manholes except that the top grate instead of a cover. They are placed at the lowest point in a swale or a depression to collect the runoff and pass it into the storm drainage system which empties into the local stream.
Gate valve
It is intended to be entirely off or entirely on
Globe valves
Are used to turn water on and off but also to meter or throttle the flow at intermediate rates. Globe valves restrict flow even when wide open.
Check valves
A backflow preventer, it prevents water from moving backwards through the system. Usually at the entrance to the building.
Sanitary trap
The water in the trap keeps the methane gas that is generated in the sewers below from rising up into the buildings
Selective surfaces
Are surfaces that have a high absorptivity in one wavelength (solar) and low emissivity in another. (Infrared)
Convection
Convection is the only means of heat transfer which is strictly directional. It never transfers heat downward.
Trombe wall
The trombe wall adds a convective loop to the system, by trapping a layer of air between the wall and the external glass skin. There is a one way vent at the top of the wall that lets warm air in. There is a one way vent at the bottom of the wall that lets cold air in.
Water wall
Consists of a tank or a collection of large vertical tubes filled with water and placed next to the window inside the building. Water stores 5 times more heat than concrete.
Flat plate collector
A flat surface titled at approximately the right altitude and angles to receive most of the suns rays.
Focusing collector
Consists of either a parabolic dish or an arrangement of lenses which focuses incoming light onto a tube or a point.
Enthalpy
The total of sensible plus latent heat stores in the air. It is also known as Total Heat.
Emissivity
The measure of an objects ability to absorb and then radiate heat.
Emittance
The energy radiated by the surface of the body person per unit area.
Latent heat
Heat required to convert a solid into a liquid or vapor, or a liquid into a vapor, without change of temperature, given in BTU
Sensible heat
Amount of energy released or absorbed by a chemical substance during a change of temperature, changes the temperature but not the state, given in to BTU
Specific heat
The amount of energy required to raise the temperature of a material by 1°, the capacity to store heat, given in BTU
Evaporative chiller
Or a cooling tower is that large box with Oliver’s exhausting humid air or even mist that you so often find next to an office building.
Effluent
liquid waste
Ball valve
Allows one way flow is opened/closes by pressure on a ball that fits into a cup shaped opening used for regulating flow
Butterfly valve
Allows one way flow mechanism is like a rotating dish attached to a spindle used for isolating or regulating flow
Relief valve
Used to control or limit the pressure in a system by allowing fluid to divert an alternate route allowing the pressure to drop then the valve closes.
Current
Measures in Amps, its the amount of flow through a circuit
Voltage (V)
Measured in volts, the amount of force or potential in a circuit
Resistance (R)
Measures in ohms, the amount that slows down the circuit
Power (P)
The rate of energy transfer, expressed as energy / time in hours
D.C. Current
Current that flows in one direction with constant voltage
AC current
Direction of the flow can be reversed rapidly by reversing the voltage resulting in a sine wave when plotted.
Ohms Law
The building block to energy. It states that current is directly proportional to voltage and indirectly proportional to resistance. If voltage goes up current goes up.
Reverberation time
The time it takes the sound level to decrease 60dB after the source has stopped producing sound
Radiation
It is electromagnetic radiation generated by the thermal motion of charged particles in matter
Conduction
Transfer of heat when two bodies are in direct contact with each other
Embodied energy
A measurement of the amount of energy consumed to produce a specific amount of a material
Zeolite process
It is used to soften water that has a high mineral content
Lightning protection system
It is designed to provide a continuous path from a building to the ground. Unfortunately there is no such thing as preventing a lightning strike.
Photoelectric smoke detectors
Like the ones found in homes. It has a beam of light on a sensor, if the beam is obscured by smoke the alarm sounds.
Declination angle
Is the angle of the earths axis in comparison to the position of the sun
Angle of View
As you step closer to a surface you exchange more heat with surfaces
Emittance
Hotter surfaces that radiate heat
Mean Radiant Temperature
At any point is a result of the combined effect of a surfaces temperature and angle of exposure
Absorbance
Dark and matte surfaces absorb more heat
Variable Air Volume (VAV)
Damper per zone Cannot heat one zone while cooling another Damper cannot shut all the way off because it cuts off the required air per code
Terminal reheat with VAV
- Heating element inside VAV box
- Lots of control
- Waste energy
- Best control over outside air
Dual Duct System
Creates both hot and cold air at the AHU Mixing box (Combines air) Max 100’
Fan Coil Unit
Runs cooling pipes into each space where a fan pushes the cool air into space
Evaporative condenser
Water sprayed over condenser aids in the cooling of the condenser through evaporation
Air Air System
Cooled through air Separate mechanical room Twi fans
Multi Split System
Each indoor or outdoor unit can be either a condenser or an evaporator when needed
Chilled Beam System
- Radiator in the ceiling used for cooling
- Not cold enough for condensation
Swamp Cooler
Hot dry air adding moisture and causing evaporation or cooling
Waste Stack
Contains only gray water
Shallow Pump
Anything up to 25 feet sucks water out of underground pump
Deep Well Pump
Send water underground then sucks water up and stored in tank
Vacuum Breaker
Usually on the top of a toilet, used for backflow prevention
Nonmettalic sheathed cable
flexible cable ; only used in houses not protected well
Steel electrical conduit
Protects wire, supports wire, used in buildings larger than residential, expensive, time consuming and protects building
Flexible armored cable
Connects conduit from J-box to light fixture outlet
Rectifier
Is an electrical device that converts alternating current (AC) while periodically reverses direction to direct current (DC) which flows in only one direction
Inverter
Changes DC to AC used with PV panels.
What is the footcandle of most offices?
Most offices are 30-50
color rendering index
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Incandescent Lamp
- Hi CRI = 100
- Produces heat
- Wasted Watts
- Short Lifespan
- Lamp Life = 2k hours
- Efficacy = 20
- CCT= 2500 degrees
Fluorescent Lamp
- Uses phospherous powder
- Cooler
- High efficacy = 70
- CRI = 80+/-
- Lamp Life 15k hours
Metal Halide Lamp
- Good CRI =85
- Cool Light
- Slowly turns on
- Lamp Life = 15k hours
- Efficacy = 80
- CCT= 4000 degrees
High Pressure Sodium Lamp
- Poor CRI = 20
- Outdoor Applications
- Efficient / Long Life Lamp Life= 25k hours
- Efficacy = 100
- CCT= 2000 degrees
Low Pressure Sodium
- CRI= 0
- Super long life
LED Lamp
High CRI = 85 Produces little heat Difficulty shedding heat may include fins Long life = 50-100k hours Efficacy = 90 Light does fade over time
Ballast
regulates the current
Specular Reflection
The angle of reflection = the angle of incidence
Ray Tracing
Tracing the sound paths from the source
First order reflections
Sound paths that include more than one surface
Second Order Reflections
Sound path has traveled further is weaker, reflected from multple surfaces
Reverberation Time
is defined as the length of time required for sound to decay 60 decibels from its initial level.
Concert hall = 2 sec
Opera House = 1.5 Sec
Theater = 1 sec
Classroom = .75 sec
Impact Insulation Class
is an integer-number rating of how well a building floor attenuates impact sounds, such as footsteps. A larger number means more attenuation.
Anything lower than NC 30 = quiet
Anything higher than NC 55 = noisy
Transmission Loss
Measure at every octoband to describe the robustness of an assembly
Sound Transmission Class
Single number rating or an integer rating of how well a building partition reduces airborne sound.
Sound aka wavelngth Formula
Wavelength = velocity of sound / frequency of sound
In ground elevator
Oil in cyclinder used as fuel , not efficeint, slow
Traction Elevator
Uses a piston to move, efficeint, fast, smooth
Direct Plunger elevator
Environmental concerns
Holeless Elevator
Max lift of 15 feet
Roped Hydro Elevator
Expensive and problematic
Telescoping Holeless
Max lift of up to 40 feet
Geared Elevator
Max rise of 150’ , number of stops between 5-15, Speed is 500fpm
Sabins
is defined as a unit of sound absorption. It could be calculated with either imperial or metric units. One square foot of 100% absorbing material has a value of one.
Decibel
a unit used to measure the intensity of a sound or the power level of an electrical signal by comparing it with a given level on a logarithmic scale.
Insolation
exposure to the sun’s rays.
U-factor
The rate of heat loss is indicated in terms of the U-factor (U-value) of a window assembly. The lower the U-factor, the greater a window’s resistance to heat flow and the better its insulating properties.
R-value
the capacity of an insulating material to resist heat flow. The higher the R-value, the greater the insulating power.
Zeolite process
A process used to soften water that has a high mineral content
smoldering stage
The first stage of any fire is the smoldering stage. When heat is applied to a combustible material, the heat oxidizes the material’s surface into combustible gases. The oxidation process is exothermic, meaning that the oxidation process itself produces heat.
declination angle
the angle of the earths axis in comparison to the position of the sun.
Cast iron pipe
Typically used for sanitary lines in nonresidential buildings because they are noncorrosive.
PVC Pipe
Often used for cold water supply lines also used for sanitary lines.
Blower door
A fan that can be mounted in a door frame it is used to pressurize or depressurize a building to measure air infiltration or leakage
Nanometer
Measures differences in pressure between two spaces.
flow hood
It is placed over a register or diffuser to measure output
centrifugal governor
Sets the brake and shuts off the power to an elevator, the first safety device.
submersible pump
Commonly used for small buildings and residences with a private water supply from a well.
suction pumps
Work best in shallow wells like less than 25 ft
vertical displacement ventilation approach
It relies on the difference in density between zones or strata in the space. It is quiet, excellent ventilation and no drafts.
demand controlled ventilation
uses a carbon dioxide sensor to increase or decrease ventilation of a space according to occupancy. best used in spaces where the occupancy can vary greatly.
curtain board
aka a draft curtain is an assembly suspended from the ceiling to prohibit movement of smoke and flame.
SEER
the total cooling output of a central air conditioning system or heat pump in the cooling mode, measured in Btu/hr during its normal usage perios for cooling divided by the total electrical input in watt hours, as determined by specific procedures.
groundwater
water that seeps into the ground until it hits the impervious layer of rock creating a water table.
surface water
comes from rain and snow that runs off into rivers and lakes.
yield of a well
THE NUMBER OF GALLONS PER MINUTE THE WELL provides.
jet pump
the pump and motor are aboveground and lift water by the venturi principle.
Energy transfer wheel
Energy transfer wheel transfers heat between two airstreams using a lithium chloride-impregnated heat exchanger.
Footlambert
The unit of measure of the brightness of a surface and takes into account the transmittance properties of the glass.
or a measurement of the brightness of daylight
Footcandle
The unit of measure of the light incident on a transitioning or reflecting surface.
Candela
Unit for candlepower or the measure of luminous intensity
noise criteria curve
are used to specify the allowable sound pressure levels at octave band center frequencies
LAN System or Local Area Network
a system of individual computers, computer servers, and wired or wireless connections that allows all the users in an individual building or complex of buildings to share data on a nonpublic network.
load factor
The ration of the average power used to the maximum power demand is called
two-way switch
One switch controls a light or other device it is called a two-way switch.
three-way switches
when two switches are used to control the same device
four way switches
control the same device from three or more locations
Conductance
The amount of time of heat lost through one square foot of any given material per hour
Resistance
The number of hours it would take for one BTU to pass through a material of a given thickness.
Busbar
Rectangular bars of copper that carry high voltage
Busway
Multiple Busways in a metal housing
