General Mix Flashcards
Which occupancy group requires a rated fire wall between it and every other occupancy group?
Residential!
How would one calculate the minimum weight of the wall shown in the drawing? Code requirement that stabilizing moment is 1.5x the overturning moment
Correct. This is a three-part calculation. First, we must calculate the moment about point B. Then, we must calculate the weight of the wall needed to stabilize against this moment. Finally, we must apply the 1.5 factor of safety.
- Step 1: Calculate the moment about point B.*
- The overturning moment will equal the sum of moments produced by the lateral forces about point B. We calculate around point B because that is the point around which the structure would overturn, if forces acting from the left of the diagram were strong enough to overturn it.*
The force at the 2nd floor is 8 kips, and is 15’ away from point B along the Y-axis. The force at the 3rd floor is also 8 kips, and is 25’ away from point B along the Y-axis. The force at the 4th floor is 12 kips and is 45’ away from point B along the Y-axis. The equation is as follows:
- M ov(B) = 8 kips x 15ft + 8 kips x (15ft + 10ft) + 12 kips x (15ft + 10ft + 10ft)*
- M ov(B) = 8 x 15 + 8 x 25 + 12 x 35*
- M ov(B) = 740 kip-ft*
- Step 2: The stabilizing moment is given by the following equation, where ‘w’ is the weight of the wall needed to stabilize the structure. (We will use a capital ‘W’ in the next equation, which accounts for the factor of safety.)*
- Since the wall acts upon the centroidal axis of the structure (that is, it is in the middle of the building), we must find the distance along the X-axis from point B to the wall. Since the building is 30 feet wide, we divide 30 in half to arrive at the distance of the moment arm.*
- By definition, the stabilizing moment, M st(B), is equal to the overturning moment, M ov(B).*
- M st(B) = w (30 ft / 2)*
- 740 kip-ft = w (15 ft)*
- 740 kip-ft / 15 ft = w*
- 49.33 kips = w*
Step 3: Finally, we apply the 1.5 factor of safety. This is simply done by multiplying 1.5 times the stabilizing moment:
- W = factor of safety (w)*
- W = 1.5 (49.33 kips)*
- W = 74 kips*
Do vapor barriers prevent the movement of air?
No! Just moisture
What are the three different types of facing bricks?
FBS - Size & Color variation
FBA - Almost uniform, but vary in size, color, and texture
FBX - Extreme Mechanical perfection
When is a door a reverse swing?
When it swings towards you opening it.
What is a board foot?
Equal to a 12” x 12” x 1” piece of wood.
Which standards reflect the technical requirements for sprinkler systems?
National Fire Protection Agency (NFPA)
What are the four major causes of heat gain?
- Solar radiation through roof, walls and floors
- People
- Lighting
- Equipment
What are the two major sources of heat loss?
- Outside air infiltration
- Radiation through roofs, walls and floors
VAV HVAC
Variable Air Volume.
Just uses air.
Individual spaces control the amount of air
Can control humidity as well
Dual-Duct System
Separate ducts for heating and cooling
Uses air only
Reheat System
Uses only air.
May also filter and use outside air.
Like an in-wall unit, this system will condition air and put it back into a room.
Multizone HVAC System
Provides heating and cooling ducts to separate zones of a building.
Uses air only.
What are four types of air-only HVAC systems?
VAV
Dual Duct
Reheat
Multizone
How many BTUs is in a “Ton” of HVAC capacity?
12,000 BTU/hr is how much heat is required to turn a ton of ice into water in one day.
What is the difference between a register, grille, and diffuser?
A register has operable fins, a grille has a grate or wire weave, a diffuser is in the ceiling.
How many BTU/hr are in 1 Watt?
3.413 BTU/hr
How many Watts are in 1 Horsepower (HP)?
746 W = 1 HP
What are the typical electrical voltages supplied to a building?
Small & Residential - 120/240 volt single-phase 3-wire
Most commercial projects - 120/208 volt 3-phase 4-wire
Very-large-scale projects - 277/480 volt 3-phase 4-wire
What is Ohm’s Law?
The forumla to find resistance
Voltage = Amperage x Resistance
or V=IxR
How high should outlets be?
12”-18” AFF
Where are GFCI outlet protection required?
Bathrooms/Lavatories
Kitchens
Garages
How many feet of vertical water can 1 PSI of force lift?
2.3’ (or 2’-4”)
What type of pipes are most susceptible to water hammer?
Copper pipes!
What are the three thicknesses of copper piping?
Type K - Thickest
Type L
Type M - Thinnest
What types of plastic pipes can deliver hot water?
PB - Polybutylene
CPVC - Chlorinated Polyvinyl Chloride
What is the typical maximum allowed deflection
Length of the beam in inches
divided by
360
What is the formula for deflection in a beam (uniformly distributed load)
Deflection = 5 (load in plf x Length of beam in inches)^4 / 384 (Modulus of Elasticity x Cross-section’s moment of inertia)
How many decibels is a normal conversation?
70 dB
How many decibels is a subway train?
95 dB
How many decibels is a loud concert?
115 dB
How many decibels are not good for the human ear?
90+ dB - sustained exposure may result in hearing loss
125 dB - pain begins
140 dB - short term exposure can cause permanent damage
What type of HID lamp are particularly sensitive to orientation? and why?
Metal Halide! They are designated with a proper burning position (base-up, horizontal, base-down) and will lose efficiency and lumen power if not installed correctly.
What is the easiest way to remember the difference between a Stack Vent and a Vent Stack?
Remember that the term “stack” in Vent Stack can be plural! (But a Stack Vent obviously sounds like one vent)
The singular Stack Vent is the portion of the soil stack above the highest plumbing fixture. It is literally a vent for the stack and is open to the outside at the top.
A Vent Stack (aka, a stack of vents) is a collection of vents from a number of fixtures that share one exterior outlet.
What are some key design factors for mechanical rooms?
- Boiler rooms and chilled water plants should be adjacent! (sometimes in the same room)
- These rooms must have at least one exterior wall to permit access to fuel tanks and for ventilation
- 12’ Minimum ceiling heights (varies by equipment)
- Rooms should be long and narrow, not square, to accommodate the equipment
- Consider the noise and weight of the equipment.
What must be known to calculate the solar heat gain of a window?
The design cooling factor
and
the area of the glass
What are some problems with excessive deflection?
- Visually disturbing
- Can damage windows, partitions, and plaster ceilings
What is a Cant Strip?
An angled piece of blocking that prevents the roofing membrane from having to make a 90 degree turn where the roof meets the parapet. This makes it less likely to crack or split
What makes a story a “soft story” according to the IBC?
If it has the lateral stiffness less than 70% of that in the story above or less than 80% of the average stiffness of all the stories above.
What are some different concrete finishes?
Broom - slip resistant
Float - rough, meant to be covered by carpet or tile
Troweled (steel, light-steel) - very smooth, can be sealed or painted as final finish.
Concrete slab joints
What are the primary restrictions on surface finishes in model codes?
The Occupancy Group
Location in the Building
What is the best way to improve the transmission loss in a partition?
Add mass and resiliency
What is the maximum permissible drift of one story relative to an adjacent story?
.0025 x the story height
(.36” for a 12’ story, for example)
What are some requirements for fire extinguishers?
NFPA Requirements:
Clearly marked and visible
No more than 75’ from any occupant
Maintained, tested, labeled.
Readily accessible.
ADA Requirements:
Can’t protrude more than 4”, no higher than 48”
What is the typical order of construction documents?
Site
Civil
Arch
Structural
Plumbing
Mechanical
Electrical
What occupancy type requires a fire-rated wall between it and any other occupancy?
Residential!
What spec division covers Procurement and Contracting Requirements?
00
Remember because you want ZERO discrepancies when attaining bids and completing contracts
What spec division covers the General Requirements?
01
There is only 01 GENERAL
What spec division covers Existing Conditions?
02
Remember - there are TWO existing trees on site
What spec division covers Concrete?
03
Remember THREE main concrete elements. Foundations, Floors, and Walls
What spec division covers Masonry?
04
Remember because a brick is about FOUR inches thick
What spec division covers Metals?
05
Picture the pentagon built completely out of metal
What spec division covers Wood, Plastics, and Composites?
06
Pick up sticks (wood)! When hiking, if there are no wood sticks available, look for plastics and composites
What spec division covers Thermal and Moisture Protection?
07
Rhymes with Heaven. In heaven there’s probably perfect Thermal and Moisture protection because you’re above the clouds.
What spec division covers Openings
08
Rhymes with MATE. Juliet looked out her window (Opening) to see her mate Romeo
What spec division covers Finishes?
09
Rhymes with FINE! Once those finishes are on your building will be looking fine
What spec division covers Specialties?
10
If shes a 10/10 then she is SPECIAL for sure
What spec division covers Equipment?
11
All 11 players on a football team are wearing EQUIPMENT
What spec division covers Furnishings?
12
There are 12 CHAIRS at the table in the last supper. (second religious reference, I swear I’m agnostic)
What spec division covers Special Construction?
13
If you are going to build an ice rink (or any special construction) Mats Sundin would recommend that you look in section 13
What spec division covers Conveying Equipment?
14
More than 14 people on an elevator starts to feel a little crowded.
What spec division covers Fire Suppression?
21
The candles from a 21st birthday celebration + everyone being too drunk to deal with it = the fire alarm and sprinklers going off
What spec division covers Plumbing
22
Picture Asante Samuel fixing the pipes under my sink or my toilet.
What spec division covers HVAC?
23
HVAC rhymes with 23!
Picture Michael Jordan fixing my air conditioner
What spec division covers Integrated Automation?
25
My network router probably has about 25 devices connected to it.
What spec division covers Electrical?
26
There are TWO switches and SIX outlets in my bedroom
What spec division covers Communications?
27
There are currently TWO SEVENS in my recent text messages (forgive me)
What spec division covers Electronic Safety and Security?
28
I bet the Atlanta Falcons wished they had a little more SAFETY and SECURITY when they were up 28-3 in the Superbowl
What spec division covers Earthwork?
31
Picture a bulldozer clearing a 31 shaped area of earth
What spec division covers Exterior Improvements?
32
Picture a big 32 made from pavers, landscaping, retaining walls, and cleaning of exterior materials to make the house beautiful or improved
What spec division covers Utilities?
33
This is my lucky number, and I am the one who pays the Utilities for our apartment
What spec division covers Transportation?
34
Picture Auston Matthews on a subway
What spec division covers Waterway and Marine Construction?
35
Think of how many times I-35 is probably spanning a waterway and needs to use this division to build the piers in waterways.
What spec division covers Process Integration?
40
Most don’t really PROCESS their INTEGRATION into society until around age 40
What spec division covers Material Processing and Handling Equipment
41
What documents are in the Project Manual?
The written documents prepared for, or made available for, procuring and constructing the Work
Bidding Requirements
Contract Forms
Specs
!NOT DRAWINGS!
What documents are in the Contract Documents?
Those items so designated in the Agreement, and which together comprise the Contract.
!Not Bidding!
Contract Forms
Specs
Contract Drawings (CDs)
Addenda
What is included in the Bidding Documents?
Everything!
Bidding Requirements
Contract Forms
Specs
Contract Drawings (CDs)
Resource Drawings (existing)
Addenda
Modifications
Performance Specs
a performance specification tells the contractor what the final installed product must be capable of doing. It is up to the contractor to work out the process, as long as the desired result is achieved.
Prescriptive Spec
Used for highly complex portions of a project. An architect is prescribing a specific recipe for how to build or install something on the site.
Proprietary Specs
Single approved product type!
Vapor Retarder Classes
Class I - Very low permeability (.1 perms or less) aka blocks the most
Class II - Low permeability (.1 - 1 perms) blocks a lot
Class III - Medium permeability (1 - 10 perms) allows most vapor
When should you avoid using a Class I Vapor Retarder?
Anywhere that moisture will be moving through the assembly from the outdoors easily. Climate zones 1-4 for example, with hot and humid climates. A strong vapor barrier on the inside of the assembly here will trap moisture inside the wall.
When does the IBC require a Class I or II Vapor Retarder?
In climate zones 5, 6, 7, 8 and marine 4 (on the interior side of framed walls)
Cement Types
Type I - General Purpose
Type IA - Air Entrained (use where freezing)
Type II - Moderate sulfate resistance (use when lots of sulfate in runoff)
Type III - High early strength (quick turn-around desired)
Type IV - Low heat (slow) used when large quantities like dams
Type V - High sulfate resistance
How many lumens in 1 candela?
12.57 lumens
A lumen is the amount of flux on an imaginary sphere surrounding the source at one foot away. The area of a sphere is 4pi, so 1 candela x 4pi = 12.57
What should one do when the ground is frozen but you are trying to pour a foundation?
Concrete should never be placed on frozen soil because it can subside when it thaws. Therefore, one should thaw the ground before placing any concrete.
Brick Grades
SW - Severe Weathering
MW - Moderate Weathering
NW - Neglible Weathering
Brick Types
FBS - So Not Uniform
FBA - Almost Uniform
FBX - X-tremely Uniform
What are the different fire classifications?
A - Combustibles (wood, paper, trash) All campfires
B - Flammable liquids (oil, gas, paints) Burning fuel
C - Electrical (wiring, controls, appliances) Circuits
D - Combustible metals (magnesium, lithium, titanium) D-Cell Batteries with Lithium
K - Cooking (oils, grease) Kitchen Fires
What is a square, in terms of roofing?
A square is 100 square feet and is the measurement used when estimating roofing.
What materials have a HIGH embodied energy?
Manufactured with high heat (ceramics, glass, steel, concrete)
Manuf. with chemical/petrochemical (Epoxies, paints, foam insulation, plastics, engineered wood)
Intense mining (Copper, aluminum, stone)
What materials have a LOW embodied energy?
Cellulose/Glass Fiber Insulation
Wood
Gyp Board
Plaster
Rammed Earth
What is the function of vertical stiffeners on a steel beam?
To prevent web buckling.
Where appearance is a concern, what is the advantage of knee bracing over other types of bracing?
The struts are typically short enough to be more easily hidden by a suspended ceiling.
What are metal anchor studs, or shear studs?
Connectors welded to a beam and encased in concrete.
What type of retaining wall includes a key, and what is the key’s purpose?
A cantilever retaining wall includes this to help prevent slipping.
What are two important issues to consider when designing long span structural members that are to be shipped to a site by truck?
i. That the components must each fit on a truck ii. Be as large as possible to minimize the number of field connections
On what two drawings would you expect to find information about both ceiling grids and lighting fixtures?
i. RCP ii. Electrical Lighting Plan
What is an economizer cycle?
a. The introduction of fresh air into the indoor air. i. Reduces energy costs ii. Improves air quality
What are some advantages of using a runaround coil in an air handling system?
i. Incoming and exhaust airstreams need not be adjacent. ii. High efficiency and energy savings iii. Effectiveness in high volume applications
Name three water quality problems that can be corrected with filtration.
i. Color ii. Turbidity iii. Odor
Name four common components that would be included in construction specifications under Section 07 72 00: Roof Accessories.
i. Coping ii. Vents iii. Expansion Joints iv. Hatches
Four properties of copper pipe that make it well suited for use in water supply systems
i. Corrosion Resistance ii. Low Friction Loss iii. Strength iv. Availability in Small Outside Diameters
What type of coating can be applied to make a wall or other surface fire resistant?
Intumescent Paint
What is the relationship between “resistance through a material”R and “thermal conductivity”C?
R= 1/C
What type of specification include the name of a specific manufacturers product?
Proprietary Specification
When using the CSI Masterformat, what three parts make up the section of the specifications?
Part 1: General Part 2: Products Part 3: Execution
Which contract document describes the quality and type of materials to be used?
The specification
What are three examples of live loads in a building?
i. Furniture ii. Mobile Equipment iii. People
Name 3 procedures permitted by the IBC for calculating design seismic forces
i. Simplified Analysis ii. Equivalent Lateral Force iii. Dynamic Analysis
What kinds of loads can membrane structures resist?
Tension
Two tests commonly used on concrete
Slump Test Kelly Ball Test Cylinder Test
Buildings over 30 stories with a rigid structural system cannot easily be constructed from concrete. Why not?
The moment resisting connections between beams and columns are difficult to construct.
In the IBC, in which construction type is combustible wood both permitted and allowed to be left unprotected?
i. Type IV ii. Heavy Timber
What are the three basic categories of exposure used in determining wind loading in building design?
i. Urban and suburban areas ii. Open terrain with scattered obstructions iii. Flat, unobstructed areas
What is the formula for the “moment of inertia I” for a beam with a rectangular cross section?
I=bd^3 b=width of cross section d=height of cross section
In an earthquake, what property of a building does the building’s acceleration depend on?
The natural period of the building.
How are the allowable stresses for structural steel expressed in the IBC?
As fractions of the yield stress
At what point can the actual construction costs be completely determined?
After the project is complete and the owner has made final payment.
Why would the architect review wind loads and hydrostatic pressure?
Because they might affect the structural integrity of the building and their review is required by the building code.
What is the purpose of a deduct alternate?
If the budget has been exceeded and the owner may use this to revise the scope of work to remain within the budget.
If a CM is used on the project, what is their responsibility in the budgeting process?
Cost Analysis
What are Five common applications of one-way long-span structural systems?
i. Beams ii. Trusses iii. Joist Girders iv. Pre stressed Concrete Tee Beams v. Arches
What two structural systems are used in a dual system?
i. Moment resisting frame ii. Shear walls
Two design strategies for dealing with expansive soil located in the area of a building are..
i. Remove it and replace with imported fill ii. Including piles or caisson piers in the foundation
What materials other than steel are commonly used to create a shear wall in a steel frame building?
i. Reinforcing Masonry ii. Concrete
What are the main goals of a good seismic design?
i. Safely transfer lateral loads to the foundation and the ground ii. Can absorb some of the energy that is present iii. Will not collapse is laterals loads exceed the design
Why is electrical service provided at high voltage?
Makes it possible to transmit electricity with less voltage drop and to provide service with smaller lines
Name two types of glare.
i. Direct ii. Reflected
Name three ways a retaining wall can fail.
i. Overturning ii.Sliding iii.Sinking
What are some advantages of open-web steel joists over steel beams?
Lightweight and prefabricated
What are two disadvantages to using concrete to resist lateral loads?
i. Weight ii. Brittleness
What are the four most common types of sprinkler systems?
i. Wet ii. Dry iii. Deluge iv. Preaction
What is the maximum moisture content allowed in kiln-dried lumber?
15%
What are the 3 grades of glulam beams?
i. Architectural ii. Industrial iii. Premium
What is the condition of the moment at the center column of a two-bay frame?
Negative
What is a resonant, or oscillating load?
Dynamic loads cause by wind.
What is occurring when a beam has a negative moment?
Negative moments cause the beam to bend upward
What are the main advantages of air entrained concrete?
i. Durable ii. Workable iii. Resistant to freezing
Which forces acting on a building are resisted by the use of a moment connection between beams and columns?
Lateral forces such as wind and seismic.
What is the formula to calculate the total lateral force or seismic shear at the base of a building?
V = C * W C=Seismic response coefficient W=weight of the building
What type of soil permits an allowable foundation pressure of 4000 psf?
Sandy gravel
What condition of the soil leads to the use of piles?
When it is unsuitable for spread footings.
In what kind of system are lateral-resisting members stressed in flexure?
Moment resisting space frame
What is a diaphragm and what is its function in a structure?
Horizontal or sloped system designed to transmit lateral forces to shear walls and other vertical resisting elements.
What two basic guidelines are used in truss analysis?
i. The sum of the horizontal and vertical forces at any point must equal zero ii. The sum of the moments at any point must equal zero.
What are the three functional components of a private septic sewer system?
i. Septic tank ii. Distribution box iii. Leach field
What is an RFI (request for information) and why is it used?
It is a request to the architect from the contractor to clarify a part of the drawings or specifications that are not clearly understood in the field.
Where would requirements for pier reinforcing be found in a set of construction drawings?
The structural drawings.
What are the allowable variations in actual construction dimensions versus the dimensions shown on construction drawings called?
Tolerances
What is a benchmark?
This is a fixed point from which all other elevations on the site and building are measured.
What is a heat bridge?
A piece or assembly of metal or other conductive materials that spans from the exterior to interior faces of a wall.
What is the function of an expansion joint in a curtain wall?
Allows movement due to thermal conditions in the wall.
What is the uniform Drawing System?
a. The standard arrangement of drawings and sheet organization. b. Also, establishes a standard format for schedules and drafting conventions
Typically what are the three biggest factors in the cost of a building?
i. Material ii. Labor iii. Equipment
Why would an architect be required to revise drawings without compensation?
When all base bids are above the agreed upon construction budget.
How are precast concrete sections connected?
Embedded weld plates
When is a coped beam connection used?
When the tops of two beams must be flush with each other.
What is a base bid?
Bid that meets the minimum required work when alternate bids are included in the bidding scope.
What information are wall sections drawn to show?
These drawings schematically show vertical dimensions and the construction of the floor, wall and roof.
What are the two most common ways a concrete beam can be reinforced for shear?
a. Bending the tension steel up to a 45 degree angle at the ends. b. Using vertical stirrups. (The more common approach)
What is the function of vertical stiffeners at a steel beam?
To prevent web buckling.
What are 3 characteristics of quatersawn lumber?
i. Relatively even grain patterns ii. Shrinks and swells less in width iii. Doesn’t utilize logs effectively, and thus results in more waste and higher cost
What are four types of wood that are appropriate for outdoor spaces?
i. Teak ii. IPE iii. Redwood iv. White Oak
Accelerator
A substance such as calcium chloride, added to a concrete mix to speed up its setting and strength development
Brown Coat
The second coat of plaster in a three coat plastering. Contains a large proportion of sand.
Hub
The end of a pipe that is enlarged to receive the end of another pipe to form a joint. Also called a bell.
Bar Chair
Device used to support rebars during the placing of concrete.
Groove Weld
A weld placed between two butting pieces of metal.
Weathering Steel
Steel that acquires a brownish protective oxide coating when exposed to the weather and therefore requires no paint finish.
Rigid Frame
Moment Resisting Frame - A frame with rigid joints, in which members and joints are capable of resisting vertical and horizontal forces primarily by flexure.
Stainless Steel
Generally containing more than 10% chromium.
Branch Vent
A vent connecting one or more individual vents to a stack vent.
Construction Joint
The joint between two successive concrete pours. Usually located where the shear is minimum, such as the midspan of beams.
Nonferrous Metal
Contains NO Iron. Aluminum, Copper or Lead.
Grade NW Brick
No weather brick.
Dual Duct System
Hot and cold air are supplied by separate ducts and mixed at each controlled space to provide desired supply and temperature. Consumes a great amount of energy.
Variable Air Volume (VAV)
Controls thermal load changes by varying the flow of air supply instead of varying the temperature.
Which of these building materials are considered to be non-combustible?
Steel, Brick, Concrete, CMU
What is the equation used to determine Footcandles?
Footcandles (fc)= (lumens*CU*LLF) / room sqft.
How do you prevent efflorescence?
By furnishing adequate weather protection during construction.
When is a cold joint used?
Cold joints are used when a concrete slab is too large to be completed in a single concrete pour.
When is a construction joint used?
Construction joints are used where two separate placements of concrete meet and where reinforcement may be continuous.
When is a control joint used?
Control joints (contraction joints) are tooled, sawed, or formed grooves in the concrete to create weak points where cracking can occur.
When is a isolation joint used?
Isolation joints are used where adjacent areas of concrete may move in three directions and where the formation of cracks is to be avoided.
What metals are most resistant to oxidation?
Gold and Silver
What materials are considered to be combustible?
Aluminum, Light Wood Framing, Heavy Timber
Name the types of plastics and what they are used for
ABS piping is used for drainage CPVC is used for hot and cold supply HDPE is used for exterior water supply PE is used for water supply, irrigation sprinklers, and exterior drainage PEX-AL-PEX is used for water supply and compressed air and gas PP is used for industrial supply and waste for chemical resistance and high heat PVC is used for cold water supply
What is Enthalpy?
The total amount of heat within a system.
What is the equation for R-value?
R=x/K x=thickness of the material in inches
Incandescent lighting tends to give off what color light?
Yellow
What are the flame spread ratings from lowest to highest?
A,B,C
VOC stands for
Volatile Organic Compounds
What kind of specification describes the desired end results?
Reference Specifications
What are Descriptive Specifications?
- They make the architect responsible for the proper performance of the specified items. 2. The explain all components of the specified items in detail. 3. They describe the arrangement of the assembly of the components of the specified items.
A Project Manual contains:
- General conditions of the contract for construction. 2. Instructions to bidders. 3. Sample contract and administrative forms. 4. Bid form.
Reference Specifications are:
Specifications that describe the desired end results and are used to refer contractors to federal or other standard specifications.
Proprietary Specifications are:
Are usually open but may be closed on private projects.
The maximum speed of an elevator is dictated by:
Building Height
How are freight elevators different from passenger elevators?
- They are slower. 2. Greater weight capacity 3. Doors operate differently
When are hydraulic elevators used?
Low rise buildings about 50 feet or five stories maximum and have speeds that vary between 25 and 150 fpm.
When are electric elevators used?
Used in buildings >50ft. tall and can obtain speeds of 1,800 fpm
Double wrap roping is used when:
- When high speed service is desired, additional traction is required hence double wrapping. 2. Cable life is shorter since there are more bends.
An elevator roped at 2:1 means what?
distance the cable moves:distance the car moves This example) the car speed is one half that of the cable. Also - requires only half the weight to be lifted by the motor so a smaller elevator motor can be used.
What criteria are used in specifying the maximum noise level in a given space under a given set of conditions?
NC = Noise Criteria
What is the logarithmic measure of the intensity of a sound relative to reference intensity?
IL = Intensity Level
What is reverberation time?
The time required for a sound to decay 60 dB in a space.
Fluorescent Lighting
Cool white color. Typically 40 watts or less
HID = High Intensity Discharge
Very high voltage, blue light
Types of HID Lights include:
- Mercury Vapor Lamps 2. Metal Halide Gas 3. High Pressure Sodium 4. Low Pressure Sodium
What is electrolysis?
Deterioration resulting from contact between certain alloys.
