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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 - Current
- W = Power (watts)
- V = volts
sum of sensible heat and latent heat
- measure of sound intensity
- 20 db is a whisper
- 130 db is threshold of human pain
rate of flow of lumens or watts through a theoretical surface
- 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.
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.
- Heat energy that causes a change in state.
- such as ice to water.
- 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
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
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.
- 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.
Metric equivalent to the foot-candle.
Equal to 1 meter-candle or 1 lumen/m2 (squared)
- 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
- 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.
- 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.
transferred heat energy that causes a change in the dry bulb temperature of a material nut not a change of state.
1. Drainage Field
2. Seepage Pit or Dry Well
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
Factors that affect climate comfort
- air movement
Equivalent Spherical Illumination (ESI)
Optimum lighting -the even spherical illumination of an area with all shadows and bright reflections eliminated.
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
- 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
- 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.
- changes voltage, not power, in an AC.
- used to step down voltage from line to building.
surface that maintains a reflected image - mirror
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.
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+...
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
- ratio of lumens received on a work surface to the lumens emitted by the light source.
measure of luminous intensity of a light source.
- quantitative unit for measuring the brightness as reflected from a surface.
- measured in lumens per s.f.
- defines the probably demands on plumbing fixtures.
- 1 FU = 1 unit flow rate of 1 cubic foot per minute.
- 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
- 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
change in frequency of a sound wave due to a change in distance from the source, receiver, or both
Identify Water Disrtributiion Systems;
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.
- 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
sensible heat loss or gain due to unintentional ventilation
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
- V = IR
- Voltage = Current x Resistnace (ohms)
- I = V/R,
Watts (power) = Voltage x current
- Used in AC circuits, always 1 for purely resistance circuits
Calculating Power drawn in DC
- V = volts
- I = amps
- R = ohms
Calculating power drawn in AC
W=VI x pf
- W= watts
- V = volts
- I = amps
- pf = power factor
- low frequency sounds have long wavelengths
- high frequency sounds have short wavelengths
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
(A) = S∞
- A = total absorption ( sabins)
- S = surface area (SF)
- ∞ = coefficeint of absorption
difference bewteen IL in two rooms
NR = IL (room 1) - IL (room 2)
- 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)
physical process by which sound passes around obstructions and through very small opennings.
- 25 = poor
- 30 = Fair
- 35 = very good
- 42-45 = excellent
- 46-50 = total privacy
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.
- 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
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
Minimum Efficiency Reporting Value
- rates the effectiveness of air filters.
- 1 to 16
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
- 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
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 = illumination
- I = Intensity (cp)
- d = distance
refelctance (fl) = E (fc) x refelctance % / 100
- Used to maximize visual comfort, productivity, or to reduce energy use.
- effective to twice the height of the window
Identify the following lamps
- 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.
- 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
- product of current and voltage
War of currents
- Westinghouse and Tesla (AC)
- Edison (DC)
AC won because transforming voltage was much easier and required no moving parts or maintenance.
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.
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.
- 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
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
- ∆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 - 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
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;
4. Reverberation Time (RT)
- 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
1. Rail Clamp
2. Limit Controls
3. Alignment Device
- 1. Brake
- 2. travel Range
- 3. Aligns platform and floor level
- 4. Slows elevator at last stop
- 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
- Class A freight
- Class B cars
- Class C industry related
- 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
- Sustainable sites
- Water efficiency
- energy & Atmosphere
- materials and resources
- Indoor Air Quality
- Innovation and design practice
- concerned with ecosphere and biosphere
- 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.
- community - integration, walking, housing & jobs, sidewalks & paths
- regional - integrate transmit, natural boundaries, institutions near urban cores
- implementation - gov controls planning
Solar Heat Gain 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
- 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
minimum reflectance at,
- 1. ceilings 89%
- 2. Walls 50-70%
- 3. floors 20 -40%
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
- 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