Ampere (A)
unit for measuring the amount of electricity current flowing in a conductor.
1 Volt applied across a resistance of 1 Ohm results in the flow of 1 Amp
I=W/V
I - Current
W = Power (watts)
V = volts
Enthalpy
sum of sensible heat and latent heat
Decibel
measure of sound intensity
20 db is a whisper
130 db is threshold of human pain
Flux
rate of flow of lumens or watts through a theoretical surface
Efficacy
Measure of the energy efficiency of a light source.
ratio of the total lumen output of a lamp to the total power per watt input.
Lumen (l)
measurement of the total output of a light source.
Makeup Air Handing Unit
AHU specifically designed to supply 100% outside air to a space replacing air lost through exhaust fans or building envelope.
Mean Radiant temperature (MRT)
average temp of all radiating surfaces within the line of sight of a body.
used to determine comfort zone.
measured using globe thermometer.
Latent Heat
Heat energy that causes a change in state.
such as ice to water.
Sabin
A unit of sound absorption.
one unit is equal to one s.f. of totally absorptive surface.
0 = all sound is reflected
1.0 = all sound is absorbed
Resistance (R)
R = 1/C
Resistance is the reciprocal of conductance.
Is a measure of the insulating qualities of a material.
R = x/k
x = thickness
k = conductivity
Luminance
A measure quantity of light at a given point on a surface coming from a given direction accounting for the reflectance and transmittance of materials.
Effluent
Liquified sewage that flows from a buildings disposal system.
Flows into a public sewer, septic tank, or leach field.
Foot Candle (fc)
measure of illumination equal to one lumen.
the amount of luminance from one lumen on a one s.f. surface.
Lux
Metric equivalent to the foot-candle.
Equal to 1 meter-candle or 1 lumen/m2 (squared)
Hertz (Hz)
unit of frequency
number of cycles per second is called the frequency.
60 cycles per second = 60 Hz
Electricity is analogous to water flow
Voltage (volts) - Pressure (psi)
Current (amps) - Flow Rate (gpm)
Resistance (ohms) - Friction
Preaction Sprinkler System
used in dry pipe sprinkler systems where the danger of serious water damage is present.
used ion conjunction with more sensitive fire detection systems that when triggered initially empty the pipes of the compressed air and fill with water. the water is not released until the sprinklers are triggered.
Objectives of Fire Safety
1. Protection of life.
2. Protection of property
3. Maintaining Building Operation
British Thermal Unit (BTU)
the amount of heat energy required to raise the temperature of one pound of water by one degree F.
Parts of the Eye
Lens: focuses
Iris: Controls brightness
Retina: Senses color, and black and white
Identify:
1. ASHREA
2. ANSI
3. ASME
1. ASHREA - American Society of Heating, Refrigeration, and Air-Conditioning Engineers, Inc.
2. ANSI - American National Standards Institute - minimum requirements for energy conservation in buildings
3. ASME - American Society of Mechanical Engineers
Flat Plate Collectors
Active Solar Water Heating System
-most common / least costly
-4'x8' insulated glazed box with piping manifold connected to the black metal flat plate.
Concentrating Collectors
Active Solar Water Heating System
uses metal reflectors to concentrate suns rays on a tube or point.
generate higher temps and more efficient use of surface area
more complex and expensive
Type of voltage systems and their uses
120/240 v single phase - 3 wire system used for residence and small office.
277/480 v 3 phase - 4 wire system used for large commercial
2400/4160 v 3 phase - 4 wire system used for very large commercial and industrial
120/208 v 3 phase - four wire system used for small and medium commercial. allows various electrical loads.
Sensible Heat
transferred heat energy that causes a change in the dry bulb temperature of a material nut not a change of state.
Identify:
1. Drainage Field
2. Seepage Pit or Dry Well
3. Mound
4. Sand Filter
5. Percolation test
1. Drainage Field - onsite sewer treatment system - Effluent form septic tank drains to perforated pipes surrounded by gravel in trenches - seeps into soil.
2. Seepage Pit or Dry Well - onsite sewer treatment system. below grade perforated concrete cylinder.increase risk of waste water flowing into water table. - concentrated point of distributing
3. Mound - onsite sewer treatment system. drainage field above existing grade. may require pump to move effluent from septic tank.used when water table is high
4. Sand Filter - onsite sewer treatment system. effluent from septic to open air filter treatment pit at or above grade.- flows through sand to soil.used when water table is high
5. Percolation test - determine rate at which soil can absorb effluent
Regional Climate Zones
Cool
Temperate
Hot-arid
Hot-humid
Factors that affect climate comfort
temperature
humidity
precipitation
radiation
air movement
Equivalent Spherical Illumination (ESI)
Optimum lighting -the even spherical illumination of an area with all shadows and bright reflections eliminated.
Anode
a piece of metal inserted into a water tank to collect hard-water deposits in order to keep them from forming on the heat exchanger
Dew Point
the temp at which water vapor in the air becomes saturated and condenses into water droplets.
as the temp cools, the air can no longer hold as much water vapor and the vapor condenses
(k)
thermal conductivity
ability of a material to transmit or conduct heat or electricity.
determine the size of a heating system for a building
calculate total heat loss
the coefficient of heat transmission (U valve) for each assembly (walls, windows, roof) and add all the U values.
transformer
changes voltage, not power, in an AC.
used to step down voltage from line to building.
Specular
surface that maintains a reflected image - mirror
Ohm's Law
states that the current (I) that will flow in a DC circuit is directly proportional to the voltage (V) and inversely proportional to the resistance (R) of the circuit.
I=V/R
Four Stages of Fires
1. Incipient Stage - no visible flame or significant smoke or heat. invisible products of combustion are given off - ionization or gas detectors
2. Smoldering Stage - visible smoke - photoelectrical detectors
3. Flame Stage - fire exists without significant heat - flame type detectors
4. Heat Stage - openly burning flame producing heat. - heat activated or temperature detectors.
Thermal Lag Factor
amount of time it takes radiant heat gain entering a space to be absorbed into the room air.
determined by the thermal capacity of the materials within and surrounding the space.
1. Effective Temperature
2. Specific Heat
3. Sensible Heat
4. Latent Heat
1. measure of a combination of dry-bulb temp, relative humidity, radiant energy and convection.
index of thermal sensation, not actual temperature
2. (Cp) - ability of a material to store heat in relationship to the materials weight.Specific heat is multiplied by the materials weight to determine thermal capacity
3. transferred heat energy that causes a change in the dry bulb temperature of a material nut not a change of state.- #of people x 225 btu/hr
4. Heat energy that causes a change in state.such as ice to water.
Coefficient of Heat transmittion
U factor
used to calculate heat loss of a building assembly
U= 1/ ∑R or U = 1/ R1+R2+R3+...
Crack Method
measures infiltration by adding together all the crack in a building into a linear foot and consulting a table for wind speeds and type of openings.
Coefficient of Utilization
(CU)
ratio of lumens received on a work surface to the lumens emitted by the light source.
Candle Power
measure of luminous intensity of a light source.
Foot Lambert
quantitative unit for measuring the brightness as reflected from a surface.
measured in lumens per s.f.
Fixture Unit
(FU)
defines the probably demands on plumbing fixtures.
1 FU = 1 unit flow rate of 1 cubic foot per minute.
Specific Heat
(Cp)
ability of a material to store heat in relationship to the materials weight.
Specific heat is multiplied by the materials weight to determine thermal capacity
Security Systems
1. Passive Infrared Detector (PIR) - detects change in temp.
2. Motion Detector - uses doppler effect
3. Mechanical Motion Detector - uses spring mounted contacts
4. Photoelectric Device - laser
5. Acoustic Detector - noise level exceeds preset limit
6. Normally closed contact Device - doors and wndows
Doppler Effect
change in frequency of a sound wave due to a change in distance from the source, receiver, or both
Identify Water Disrtributiion Systems;
1. Hydropneumatic
2. Down feed distribution
3. Upfeed distribution
1. supplies water to floors above by a pressurized tank in basement
2. tank on roof
3. uses existing pressure in water main. - small or low rise buildings.
1. Stack Vent
2. Vent Stack
3. Soil Stack
4. Waste Stack
Stack Vent - pipe that rises above the highest fixture in a building used to vent the soil stack.- ROOF
Vent Stack - vertical pipe providing air circulation to and from plumbing fixtures. inside bldg.
soil stack - discharge from toilets and urinals and all fixtures
waste stack - carries discharge from fixtures other than toilets and urinals
Life Cycle Costs
Sum of:
Investment of first costs
maintenance and repair costs
amortization or replacement cost
operating costs
Head / Pressure
Head - height of a column of liquid
Pressure - weight at given height of column of liquid
head = pressure x 2.31 ft.
Inverse Square law
sound and light intensity is inversely proportional to the square of the distance b/w the source and the receiver.
Lighting Systems;
indirect
semi-indirect
direct-indirect
Semi-direct
Direct
indirect - 90%-100% of light is directed upward - shadowless, even with no glare - inefficient
semi-indirect - 60% - 90% of light is directed upward- low reflectivity and glare
direct-indirect and general diffuse - equal distribution of light - efficient.
Semi-direct - 60% - 90% of light is directed downward
Direct - 90%-100% of light directed downward
Fan Coil System
high initial cost
but very efficient
can heat, cool or ventilate
Infiltration
sensible heat loss or gain due to unintentional ventilation
Unitary System
hvac system that pulls outside air into the serviced room through mechanical ventilation
Automatic Fire recall System
brings elevator cars to predetermined floor
light source color
fluorescent - warm white -yellowish / cool white - white
incandescent - yellowish flattering to skin
mercury vapor - blue green light - poor color rendition
high-pressure sodium - yellow
low-pressure sodium - yellow with higher effiacy
Ohm's Law
V = IR
Voltage = Current x Resistnace (ohms)
I = V/R,
Watts (power) = Voltage x current
Power Factor
Used in AC circuits, always 1 for purely resistance circuits
(pf)
Calculating Power drawn in DC
W= I(IR) or W=VI
w = watts
V = volts
I = amps
R = ohms
Calculating power drawn in AC
W=VI x pf
W= watts
V = volts
I = amps
pf = power factor
wavelengths
low frequency sounds have long wavelengths
high frequency sounds have short wavelengths
Intensity Level
changes 6db with doubling or halfing the distance
coefficient of absorption
(∞ )
used ot define a materials sound absorption characteristic.
1.0 = 100% absorption ans 0 reflection
Total Absorption
(A) = S∞
A = total absorption ( sabins)
S = surface area (SF)
∞ = coefficeint of absorption
Noise reduction
difference bewteen IL in two rooms
NR = IL (room 1) - IL (room 2)
Transmission Loss
TL
ratio expressed in decibels of the acoustic energy radiated by the barrier to the acoustic energy incident on it.
Stiffenss reduces TL ( most effective at low frequencies)
Mass increases TL (most effective at high frequencies)(doubling mass increase loss by 6db)
diffraction
physical process by which sound passes around obstructions and through very small opennings.
STC levels
25 = poor
30 = Fair
35 = very good
42-45 = excellent
46-50 = total privacy
Identify:
1. Dry Bulb Temperature
2. Relative Humidity
3. Wet Bulb Temperature
4. Globe Temperature
1. Dry Bulb Temperature - air temperature as indicated on typ thermometer
2. Relative Humidity - water vapor held in the air
3. Wet Bulb Temperature - evaporative cooling temperature
4. Globe Temperature - measured with globe thermometer representing the balance of heat gained by radiation and heat loss by convection.
Identify
1. Conductor
2. Conduction
3. Conductance
4. Convection
5. Radiation
6. Evaporation
1. Conductor - wire, cable or busbar that carries electrical current. - 6 gauge or larger is a cable - 8 gauge or smaller is a wire
2. Conduction - energy transfer between two bodies by direct contact.
3. Conductance - (C) - rate of heat flow through a solid material. - # of BTU's per hour that flow through 1 s.f. of material when temp drops 1 degree
4. Convection - energy transfer between two bodies by a third medium. Fluid
5. Radiation - energy transfer between two bodies by energy waves.
6. Evaporation - energy transfer between two bodies by vapor
Calculate temperature gradiant at given layer of an assembly
∆T layer = (R layer / R total)∆T total
Heat Loss Calculation per Design Day
Heat Loss Calculation for year
q = U A ∆T
q = Heat loss
U = 1/R
A = Area
∆T = change in temperature
q = U A 24DD
q = Heat loss
U = 1/R
DD = degree day
Degree Day vs. Design Day
Degree day is a day whose temp is 1˚ less than 65˚. A day @ 63˚ is a 2DD day
Design Day is a day colder than 98% of other days
Identify these Sun Path Diagrams
1. Gnomic
2. Equidistant
3. Stereographic
4. Rectilinear / Orthographic
1. Gnomic - places observer at center of the projecton, low sun angles extend to infinity, rarely used
2. Equidistant - used solely by USA
3. Stereographic - observer fxed at top of hemisphere, used widely accross the world except USA
4. Rectilinear / Orthographic - Straight on like Plan View
Solar Heat gain Factor
qr = (SC) Area
qr = Solar heat gain Factor
SC = Shading Coefficient
one ton of HVAC
12000 BTU
MERV Rating
Minimum Efficiency Reporting Value
rates the effectiveness of air filters.
1 to 16
Identify:
1. John Gorrie
2. Willis Carrier
3. Larkin Building
4. Thomas Migdley
5. Stuart Cramer
1. John Gorrie - 1842 - compressor technology to create ice to cool air
2. Willis Carrier - 1902 - First modern electrical air conditioner
3. Larkin Building - FLW - 1904 - first entirely air conditioned office building
4. Thomas Migdley - 1928 - created freon
5. Stuart Cramer - coined the term Air Conditioning
Compression / Expansion
Bike pump compressed air - gets hot
gas canister released air - expandes and cools
compressive refridgeration
compressor -refrigerant in gas form is compressed into a liquid
condenser - refrigerant passes through and latent heat is released
evaporator - expands refrigerant, vaporizes back to gas absorbing surrounding heat.
Constant Air Volume
air is treated at a central source.
air flow is controled at separate areas by dampers and vents - temp is controled by single thermo
singel Zone
water is heated, air passes by water
Multiduct CAV uses reheat untis to fine tune air going to separate zones
Single Duct Variable Air Volume
Similar to Singel CAV
Each zone has its own controles to determine volume of air flow.
Air-Water induction System
rarely used today.
air temp is controled by contact with hot or cold water in the induction unit.
each space is individually exhausted.
Fan Coil system
usually located below windows
fan mixes existing air with an exterior supply, and is cooled / heated by water.
Thermo controls ater supply to unit.
no fanroom or ductwork
Closed Loop Heat Pump
all water system
best in temperate climates
Identify these componets of a HVAC System
1. AHU
2. Chiller
3. Cooling Tower
4. VAV Box
1. Air handler Unit - used to condition and circulate air.
2. Chiller - removes heat from a liquid using compression or absorption.chilled water is used to cool and dehumidify air
3. Cooling Tower - water cascades inside a louvered box with aire moving over it to cool the water.
4. VAV box - device that manages flow of air at the zone level.
Transmittance / coefficient of transmission
The ratio of total transmitted light to the total incident light
Inverse Square Law in terms of Light
used to determine fc at a distance from the source
E=I/d(squared)
E = illumination
I = Intensity (cp)
d = distance
reflectance
refelctance (fl) = E (fc) x refelctance % / 100
Daylighting
Used to maximize visual comfort, productivity, or to reduce energy use.
effective to twice the height of the window
Identify the following lamps
1. PAR
2. MR
3. ER
4. HID
1. Parabolic Aluminized Reflector - reflective coating inside the lamp increases the efficiency and allows more precise beam.
2. Miniature Reflector - available in variety of wattages and beam spreads.MR 11 MR 16 - number indicated size in 1/8's of an inch.
3. Elliptical reflector
4. High Intensity Dischargetypes - Mercury vapor, Metal Halide, high and low pressure sodium vapor, and Xenon.
Identify CRI
Color rendering Index - how a light compares to daylight
maximum is 100
Zonal Cavity Method Equation
Illuminance = (initial lamp lumens x CU x RLLF x NRLLF) / Area
initial lamp lumens = lumens per lamo x lamps per luminare
CU = coefficient of utilization
RLLF = recoverable light factors
NRLLF = non-recoverable light factors
Types of Fires
Class A - common combustibles
Class B - flammable liquids, gases
Class C - Energized electrical equipment
Class D - Combustibel metals
Class K - Kitchen fires
Types of Fire Extinguisher
Class A - water based for class A fires
Class ABC - multipurpose dry chemical
Class ABC Halon 1211 - less cleanup than Class ABC
Class BC Carbon Dioxide - displaces air, cuts off oxygen
Power Factor (pf)
the phase differnece between voltage and current in an alternating current circuit.
circuits with one resistive load (incadenscent light or elec heating elements) pf is 1.0
power
product of current and voltage
W=IV
War of currents
Westinghouse and Tesla (AC)
Edison (DC)
1880's
AC won because transforming voltage was much easier and required no moving parts or maintenance.
Electrical Panels
1. Connected Load
2. Maximum demand
3. Demand Factor
1. Connected load - total load on a system if everything is on simultaneously
2. Maximum demand - greatest load delivered over a specified amount of time
3. Demand factor - ratio between max demand and connected load. used to estimate the capacity of a system accounting for the probability that only a portion of the connected load will be applied at a time.
Elec. history
1. Volta
2. Faraday
3. Edison
4. Tesla
5. First Elec Code
1. first battery 1800
2. first motor 1821
3. light bulb 1879
4. AC vs DC 1880
5. 1881 N.E.C.
Well Pumps
1. Reciprocating
2. Rotary
3. Ejector
4. centrifugal
1. Reciprocating - cylinder and piston with valves - similar ot car engine
2. Rotary - spiral rotor
3. Ejector - uses venturi effect and a water jet sent from surface to impel water to rise
4. centrifugal - a wheel like impeller rotates - spiral paddle system
Water pressure
1 PSI lifts a column of water 2.3 feet.
Expansion Bend / Loop
extra set of curves in a pipe run that can contract and expand to accommodate thermal movement
helps to absorb water hammer
Maximum height of water fixture?
take pressure at water main, subtract known pressure losses and pressure required at fixture, then multiply by 2.3 to get max height.
Pipe Thermal Expansion
∆L = L K (T2-T)
∆L = change in length
L = Length
k = coefficient of expansion
T = original temp
T2 = final temp
Water pipes unsupported lengths.
4, 6, 12
pvc = 4'
copper = 6'
steel = 12'
Angle Valve
used mostly for plumbing, has metering or flow restriction capabilities
Check Valve
backflow preventer
Gate Valve
entirely on or off
Globe Valve
restricted flow even when open
Fire Alarm Systems;
Conventional
Addressable
Addressable analog
conventional - alarm signal only
addressable - identical to conventional but each detector is a separate zone
addressable analog - smart detectors, computer analyzes alarm to cut down on false alarms
Adding Decibels
60db + 65db ≠ 125db
for the difference between db's, add to the higher
0 to 1 = 3
2 to 3 = 2
4 to 9 = 1
< 10 = 0
60 + 65 = 66db
Properties of sound;
1. Reflection
2. Refraction
3. Diffraction
3. Reverberation
4. Reverberation Time (RT)
6. resonance
1. Reflection - sound bounces after hitting a hard surface at the same angle of incidence
2. refraction - some sounds are bounced back
2. Diffraction - Sound Bends
4. Reverberation - sounds persist because of multiple reflections
5. reverberation time - time it takes for the sound to decay 60 db
6. resonance - vibrating at increasing amplitude at certain frequencies.
Noise Reduction coefficient
average sound absorption at four frequencies
Elevators:
1. Rail Clamp
2. Limit Controls
3. Alignment Device
4.Bumpers
1. Brake
2. travel Range
3. Aligns platform and floor level
4. Slows elevator at last stop
Elevator History:
1. Otis
2. Siemens
3. Eiffel
4. Roux
1. Elisha Otis - 1853 introduced the safety elevator that prevented the elevator from falling if cable broke
2. Werner Von Siemens - 1880 - first electric elevator
3. Eiffel tower - 1889 -contained five hydraulic stream driven elevators
4. Roux Compaluzier - 1891 - built direct action hydraulic to lift lions into arena - Paris
Elevator Classes
Class A freight
Class B cars
Class C industry related
Elevator Types:
Hydraulic - use piston/ pump - lower speeds - piston length limits to 60' - PUSH
Traction - electric motor and use wires and ropes - PULL
Geared traction - 100- 450 ft.
Gearless traction - unlimited height
LEED
Sustainable sites
Water efficiency
energy & Atmosphere
materials and resources
Indoor Air Quality
Innovation and design practice
Natural Step
1996
concerned with ecosphere and biosphere
points:
1. elements cannot be extracted faster than they can be replenished
2. manufactured materials cannot be produced faster than they can be integrated back
3. protect existing living organisms
4. efficient use of resources.
Ahwanee Principals
1991
community - integration, walking, housing & jobs, sidewalks & paths
regional - integrate transmit, natural boundaries, institutions near urban cores
implementation - gov controls planning
Solar Heat Gain Coefficient
Shading Coefficient
ratio of the solar heat gained through a fenestration to the toal solar radiation incident on the glazing - value is between 0.0 and 0.87
ratio of solar heat gain through a glazing product compared through a 1/8" thick double strength glass under same conditions - value is between 0.0 and 1.0
Window Design
1. head height
2. effective aperture (EA) - combine Visible Light transmission (VLT) and Window to Wall Ratio (WWR)
3. Visible Light Transmission (VLT) - % of light that passes through glazing
4. Window to Wall Ratio (WWR) - net glazing area in a space divided by the gross exterior wall are not including frames and mullions
Room Design:
minimum reflectance at,
1. Ceiling
2. Walls
3. Floor
1. ceilings 89%
2. Walls 50-70%
3. floors 20 -40%
Emissivity
the measure of an object ability to absorb and then radiate heat
Equation for temperature difference between inside and outside
q=U A ∆t
q= conductance
U= product of conductance of assembly
A = exposed surface are
∆t = change in temperature
Basic electric circuit
conductor - current - voltage - resistance
Security Systems
Perimeter protection - secures entry points
Area or room Protection - field of coverage senses someone with a certain area
object protection - senses movement or tampering of an object
Lighting Calculations perpendicular to source
E = I/d2
E = illumination at receiving source
I = intensity
d = distance from source to surface