Exam 5 Flashcards
Mechanical system
Comfort
Appropriateness (parking is different than a commercial project from a mechanical system point of view)
Efficiency
Flexibility (flexibility for commercial projects is a must)
What kind of project, flexibility in designing mechanical systems is important?
Commercial
Institutional
Fresh air percentag s for different projects
For commercial and residential you won’t need a large percentage of fresh air. But for hospitals, you may need a small percentage of return air combined with a larger percentage of fresh air. It will not be efficient but it’s better for hospitals
R-value of Tyvek
Zero
It’s very effective in protecting the building from losing heat but it does not have R value
R-value of a wall assembly
Air space
Air film
You need to combine all single r values together
R(sheathing) + R (air film) + R (insulation)
Air space as long as it’s not less than 4 inches has the R-value of one 
What if the air space is way more than 4”?
Then convection current will happen inside the gap and space between two panes of glass or inside wall cavity, and the R-value will be zero or even negative 
An air seal is the molecules of air that accumulate on, and between the texture of a wall finish like a gypsum board Air seal is the molecules of air that accumulate on, and between the texture of a wall finish like a gypsum board. This is interior air film. We will have an air film outside as well.
Where will be the exterior air film? Between finish and insulation or in other words in air space on the inward layer
Which one is better in resistance to hold heat
Stud wall @16
Stud wall @24
24 - less thermal bridging
Sensible heat
Latent heat
Enthalpy
The temperature
The humidity
Total heat change (temperature and humidity)
Heating/ cooling system in commercial and residential projects.
Residential projects usually have one system for heating and cooling
Commercial projects have two systems usually for heating and cooling (usually)
Big scale commercial project
Heat losses
Check:
Infiltration
Ventilation
R-value for wall and roof assemblies
R-value for doors and windows
Slab edges, specialty are
What is the local climate? Design temp?
What is the difference between the temperature inside and outside
Infiltration
The crack estimation method (old) fits better with old buildings
Air change method: air Chang per volume of a room
To know the size of mechanical system
We need to calculate room by room - or zone by zine
Mechanical design issues
Generation: mechanical room. The scale of heat lost through ventilation or infiltration- over the spent of time- locations in factories of HDD and CDD
And fuel type - hydronic or air base- passive- inferred system - electrical system according to the population- temperature, how much room.
Distribution: duct or ductless- layout of the system- which part needs to be small or larger- how much air is needed- pipe? Duct?
Termination: diffuser for air system
radiator for Hydronic systems.
How many radiators do we need? The size of diffuser
Heating
Hydronic or air-based systems
600 degree
But distribution: 150 - 300: it’s high but the distribution system needs to be high because they lose a lot of heat during delivering the air
Cooling
Air based system
45 to 55
For distribution: 68-72
Termination: 75
Cooling or Heating, which one is more challenging
Cooling. Next card the answer
Heating system
One cubic of hot air with DT:90 will affect more than one cubic of cold air with DT:15
We will need less air for the Heating system
We will need more air to cool down a room
Hydronic system in freezing temperature if we are out of power
Glycol - it does not freeze
The pipes are that close to doors
Steam sysyem
No need for a pump. It rises by itself.
Why don’t we use the steam system for residential?
Because this system is for when we need to move a lot of heat through pipes.
Steam is bigger pipe or water pipe
Steam
Air is the largest because it needs ducts
Air-based system and leaking cost
Hydronic system and leaking cost
The cost of installing pipes
The cyst of installing ducts
No cost
Expensive
Expensive first cost
Not expensive
In general Hydronic system is more expennsive
Electric system
Toaster :)
Radiant floor system
In the vestibule because it’s far from the main body and they might not want to take pipes or ducts to the vestibule
IR or infrared system
Radiant system for outdoor places
Outdoor bars
Termination
Diffusers for air system
Radiators for Hydronic system
Which would you rather live with? Air-based Heating or in-floor radiant
Speed:
Radiant floor system: slow
Air-based system: fast
Comfort
Radiant system: excellent
Efficiency:
In-floor radiator Very efficient and sustainable
But the biggest advantage of an air-based system is we can use it for heating AND cooling
HUMIDIFICATION DEHIMUDI ALL ARE POSSIBLE WITH AIR BASE SYSTEM
Distribution for Hydronic system
Push them to the perimeter
A few of them can radiate inside
Same for air-based systems.
Size of mechanical system
Better to know the R-value and how much heat we are losing
Delta Q= U x delta A (area) x Delta T
For designing a Hydronic system we need to know the total heat We lose
Delta Q
We might have a couple of zones or 100 zones.
Why? Because one big loop cannot serve all radiators. The last radiator will not be heated enough.
Hydronic system zooning
How large is the building
South or north
Do we need for west and east?
Hydronic system termination examples
Radiators
Baseboard radiators
In floor systems
Can you add humidification or humidification to Hydronic system?
No
It’s for air based system
Radiator for basement
Because soil kind of holds the heat around, we do not need to have the same radiators for the basement that we are using for other floors
Radiator system
Boiler
Riser ( we can have separate risers for different loops)
Pipes (zones)
Baseboard radiators
Because baseboards are smaller or a lot shorter than regular radiators, we need to have more radiators to have the same result as a regular radiator
In floor radiator system
They should be around perimeters
Occasionally (very small portion) of the middle part
Mostly the middle part should be open
Different zones for radiator system
According to building Orientation (the south can have fewer pipes than the north side of a building)
Use:
Classrooms can have a single soon in case classrooms are not occupied at the same time.
Or public part of the building can have a separate zone where the private parts or offices
Radiator systems
They have specific limitations in the size and length of the pipes. Longer than a specific amount, it needs to have the next zone.
Unless you want to have a longer pipe (zone) you will need to have a larger diameter for the pipe, which will be weird in concrete slab
Freezes pipe in concrete
After melting the concert absorbed the melted ice which will be visible one day in future
Downside of radiator system?
What if you have damage you need to dig up the cincrete
Cooling
Always it’s about the air-based system
We have radiant cool in system but it’s limited
If a project is in a climate zone that does not need a cooling system. What is the best option for a heating system?
We can have only a radiator system for our project. Usually, it is a residential project that only needs heating or cooking systems. Commercial projects in different climate zones will need both cooling and heating usually air-based system is the best.
The size of a room and the number of occupants are important in the he size of a mechanical system
Cooling system humidification
It automatically dehumidifies the room.
Air handling unit
The small ones for residential buildings are vertical. The commercial projects have. Larger air handling units.
A box
Fan
Coil in front of the fan
Filter
Trunk
Branches lines
Return air trunk line
Fresh air trunk line
For the heater, we will have combustion air should be eahausted as well as fresh air for the flame
Sometimes it’s not all ducted and they use planum.
Supply air around the perimeter and return from the middle of an open room
Hispital
We do not reuse the exhausted air
Economizer
They work better in California or Arizona?
Using an exhaust air duct to make the fresh air a little warmer
Co-located
It’s a large piece of equipment
Free cooling!!!
If outside is cool enough in summer, we can bring 100% of fresh air and let the existing air inside the building out in 100%. We want to minimize. Thi economized is for climate that have very nice and cool summer.
The economized work way better in this climate like California.
Filters for air handling unit
Ion system
Charcoal for odor
Dense one to purify more buy more energy consumption
Simple rules for designing air handling units and distribution system
1- try not to cross the trunk lines. Otherwise more space of ceiling space
2- Have as few elbows as you can: all of these elbows will lose some pressure.
3- balance the length: a lot of friction will be added then we will need bigger air handling units
Try to have the duct lines from two sides right and left to cover the perimeters
Zones of a room from above to ceiling
Structure zone
Duct zone
Lighting and fire process section zone
Ceiling
How does a planum work
The supply air around the perimeter
Then the exhaust one is in the corridor but its flex comes from the corridor to the room to suck in stale air
To do so, we need not to extend the wall to the slab. There should be a bit of space for exhaust air flexes
Plenum return for office assembly
Ductless return plenum:
Instead of having a ducted return air which is in the corridor, we let the diffuser be open in the corridor. and we can have a diffuser, which is Ductless inside the room
Disadvantag s of plenum
Sound will travel from rooms to corridors. Not for HR rooms or conference room.
Air handling loops
The coils In the condenser/evaporator (refrigerant loop) could be inside a big barrel of water. Then make a loop out of the hot barrel and extend outside (Heat rejection) and then come back to the hot barrel.
The other barrel of water gets cold and we will extend a loop and coils out of the barrel (chilled water loop) and take it through rooms.
In this scenario, the coils that we have in a chilled water loop can be blown out with a fan (airside loop)
The heat rejection loops can have water water-cooling tower
Each air-handling unit can serve one floor. They are big ass air-handling units
Direct expansion
Or
DX system
It does not have chilled water loop
Sometimes we do not have to have all 4 loops (heat rejection, airside loop, chilled water loop, refrigerant loop).
There are times when we can blow air over the refrigerant loop, not the chilled water loop. We can have the refrigerant loop go around the building and be blown with a fan over the coils
Or
We can have the air handling unit on the roof and the fan blows down the cool air then to trunks in a corridor then branch toward rooms
DX examples:
Or
For big building
Better to have a chilled water loop instead of a refrigerant loop.
Chiller example
In the basement:
The refrigerant loop and barrels of water are in the basement.
The heat rejection loop goes on the roof to cool down through a cooling tower
The chilled water loop goes to each floor and will have a coil in each floor to be blown by a fan which we call it air handling unit (airside loop) to the rooms
From the air handling unit to the room, the stake air will find the way out and go through the return ducts To go back to the air handling unit or be exhausted
Fan coil example
You can take the chilled water loop to each floor and room and have a fan coil over each coil (that is attached to the chilled water loop).
No duct is needed
Less expensive
A lot of control
Plumbing pipes are going all over which is expensive
They are on the perimeter of a building
It needs to have a cooking tower
It needs a barrel of water for both the condenser and evaporator
DX in unit or DX unit
Mechanical room
The air-handling unit inside the mechanical room
Each air-handling unit has its refrigerant cycle in each of the different units. It can be for each floor. Each wing.
Self-control for tenant space
Develop a building that can provide mechanical rooms and a way for a heat rejection system
Then from each mechanical room, we will have trunks and branches to distribute the air entire the floor
Then the stale sir finds its way to the air handling unit To be conditions ned again
Advantages:
It’s very good for tenant spaces. Each unit has self-control
When I am a developer and I am not sure what tenants will move in, I will provide a mechanical room, a cooling Tower on the roof, and air handling units then tenants can design the distribution system by themself
You have three loops
Less Expensive
For multiple tenants
For example, a chiller system can be on the roof and it’s protected, it’s fire rated, and centralized control (like universities
DX RTU or package or rooftop unit system example
DX RTU- directly refrigerant in the Air handling unit and sitting on the roof.
Perfect for multiple tenants
You will have a DX package system (DX RTU) on your roof for each tenant.
Inside each package, is a refrigerant loop and it has the ability to cool down The hot part by itself is inside the package. We have a Fan inside the package which will blow down the air through a trunk and then branches installed to trunks.
We will need a big chunk of space For the trunk. We have a return system that backs up the package on the roof.
Direct expansion in the unit: each unit has a separate air handling unit that has a refrigerant loop inside.
Very cost-effective
We don’t have a lot of maintenance issues because we can change the cheap ducts
Compare this to the chiller in the basement. The chiller is for 59 years in the basement and will be protected indoors. For a long time
DX has not been for a long time. Best for tenant system
DX RTU (rooftop unit system):
Shape very steep angle: that part is the intake for outside air (fresh air) - return Air attached to the roof from underneath - fresh air and return Air join together and a fan that blows over the cold coil - we will have an inside cooking part (like cooking Tower) -
The funny sharp angle is to stop the rain from getting inside the package -
Compact
Efficient
Designing the duct
If we cannot see the ducts: rectangular
Trouble: expanding contracting and moving left and right or squishy. Shift around!!
Cheaper
Spiral or round: they hold their shape. If you can see the duct, it should be a round duct- industrial look -
When you are trying to be more efficient: round duct - low friction
Square: quite good.
Rectangular: more friction
Always add more length when you are adding an elbow to balance static pressure. Or we can use a fan to pressurize the air and balance the frictional n as well
Calculating the CFM and the pressure, then duct size.
DX system and Mini split system
Not sure if this is true
Dx system: most common system
It puts the condenser And compressor on the roof and the evaporator in the air-handling unit in each unit.
For larger projects
DX system is a central system
Mini Split: The Condenser and compressor are outside and the evaporator and fan inside - for smaller projects
People
Equipment
Lighting
What if we have too large and inappropriate mechanical system in a building
The compressor can cool down The space so fast and turn off so fast and it will never need to work harder to absorb the humidity!!! It may be very humid then condensation inside a room.
If we have too narrow duct,
Then the air will leak out and it will not be efficient
And sound
And friction
Determining the scale of mechanical system
Reheat:
When air leaves the air handling unit, it cannot take the same temperature as the last room. The last room can have A reheat system in the damper.
Sometimes in some buildings, the north side is in the shade and Will be cold even in summer. We can have a reheat system for the northern room.
Reheat is not efficient. Maybe efficient if we have to add a secondary system to warm up a cold room, then we use a heating system because it will be less expensive than a secondary system
Why top floorshould have a separate zone than other areas
because it loses a lot of heat through the roof
There will be more control when some commercial projects have a radiator system at the perimeter And an air-based system for cooling
CAV
VAV
Constant air volume: a set amount of air moving around your room. Qubic feet per minute.
Variable air volume: damper that pushes more air into a room or keeps it for the next room.
If we want a room to be one degree warmer, we need to change the temperature of the air by one degree in CAV.
In VAV, if we want to change the temp of a room one degree more, we adjust the amount of hot air dumped into a room by a damper or the amount of cold Air.
If we have a great large space with a lot of people, a constant flow of air is more logical because We Will have constant fresh air. For private offices (hourly bases) will make more sense to have VAv for different times of day.
In general, cav, you will change the temperature of the source if you want to change the temperature of a room.
This will not be Efficient if you change temperature multiple times in a day.
If you have to change the temperature of a room multiple times in a room, you should use VAV because it will change the amount of hot and cold air (adjust or manage it) by damper to increase the temp of a room.
Private offices can have different orientations and need to have different set tempt. VAV
Plumbing fixture For places that have break time like an assembly line in a factory,
The plumbing fixture should be calculated in a way that most people can use it without waiting for a long time
Plumbing system
Use of building is important
How large is the space
Do not include columns
Walls
Core
Always design for more people ( flexible design)
Supply water: we get the supply water from the mains. If we do not have a supply of water, the well should be a solution
Wastewater: to take the wastewater to the main swear system or septic tank if there is not a city system
Vent: To balance the air and let the fixture hold some water in the traps to avoid gases coming into the rooms.
The diagrammatic drawings they are not meant to be direct to clear representations of exactly what’s happening. They are a Service abstraction of a diagrammatic way to show the scale and size of the pipes.
There is a turn-off valve for the main street. Why?
When you don’t pay your bills or nobody is leaving the house, the city will shut off the main valve somewhere near to mains. Why? To avoid pipes freezing.
certain city has a fire protection tap for the pipe that we are getting from the city main.
There is only a tap, the rest of the design is for engineers to design.
We will have a meter (before or after the fire protection branch) and shut off the valve before and after the meter. Usually, we will have a booster pump after or before the fire protection that needs to have shut off the valve before and after the booster. or we can have a bypass pipe for the booster pump and use the booster pump when we need it and do not use it when we don’t need it.
After that, a cold water pipe goes up in the riser, but the main pipe will go to a boiler to heat up the water and then the hot water will join the cold water next to it. (we will have to shut off the valve For the boiler as well)
Often, when you have a fire protection system, you will have a fire pump, why? To pressurize The water in case the pressure of the main drops. The Fire Protection system is pretty big!!!
Do 13D fire sprinklers need a pump or tank? No, they are connected to the domestic water supply!
13R for buildings (Residential) up to 4 floors or 60’ high.
13 D for one or two dwelling units. No pump no tank requirement.
Then branched from the cold and hot water (not always hot water needed) for fixtures. Hot water does not go to wc.
We need to have a shut off valve for each different fixture and we will have a shut off valve for entire bathrooms in case of repairing.
If your men and women rooms are mirrored together you will have one supply pipe (hot and cold) for both sides. What if we need to repair the men bathroom? Then the women bathroom will be out of service as well.
If we put the bathrooms aligned (butterfly method), then we can have shut off the valve for their section. Or bypassing
A fire pump takes suction from a private water supply such as a reservoir or tank. A booster pump takes suction from the city water supply.
Waste water plumbing
Every time you have a plumbing fixture you will have a vent up to the roof.
Vent pipes can be branched together and goes to roof one time . Better for roof system
If a sink is far from other fixtures, it can go to the main swere line and roof for vent, individually
Waste water and vent pipes all should be in slope
True
Otherwise the toxic gases from us, will accumulate in the pipe and will make condensation and eat out the pipe
The gravity in vent pipe let the moisture to go down to the waste pipe
What if you have a fixture lower in basement and the gravity will No be helpful for waste water ?
Ejector pump will connect that fixture to the main waste line and then will allow that to leave the building by gravity. Why don’t we use ejector pump for all the fixtures in building and then lead them to the sewer system? Because the ejector pump maybe breaks!
What is sump pump
When it’s raining and your foundation is being saturated with water, sump pump will suck that water and lead it to the waste water system. Sump pump will be in basement and it will work automatically when the water level is above a certain level.
Clean out system
Every time the pipe change it’s direction we will have a clean out
Or changing direction horizontally. It was going to north and now it’s going to west. We will need a clean out here
Every 30 40 feet one clean out
Size of pipes
Fixture unit
Waste pipe: when we have more of a fixture like WC on the same pipe, that pipe will be larger in compare to other pipes.
We use the word “fixture unit” for both supply and waste pipes.
Waste pipe is larger than supply water.
If we have 4 WC next to each other and the waste pipe extend from the left one to the right one, the farthest WC on the left will need for example 3 fixture unit to push soil to the right (toward the waste pipe) then the second WC from left will need 6 fixture unit water to push the soil because it should have enough water for itself plus for the soil coming from the farthest WC on the left side.
at the end you see that you will need nine fixture unit water to push this soil to the main sewer system and then you check on the code to, for nine fixture you need how big should be a pipe.
LIGHTING DESIGN ISSUES
Scale of room is very effective
Zonal cavity method:
- where is your workplane? The height of the plane (for example a table)
-what is the wall ceiling and floor? Color? Texture?
Black walls or very textured wall, it cannot reflect good amount of light, so we will need more lighting.
-the scale of the room: if the room is smaller, we will have more reflection.
Volume of the room or height of them room?
Can the lights shed enough?
-where is the fixture?
Pendant lights or recessed light? Is the light shedding direct light or indirect or both? When we have less direct light on a work plane and more ambient light it will be less glary.
Pendant light change the distance from fixture to work plane. Closer? More direct light? But some of the pendant light will shed the light back to the ceiling( ambient light).
- maintenance: are the fixtures having dust? Tube fluorescent lighting can be very dusty. Include the lose of percentage of light. during time due to dust.
For school, you will need to build in the calculation for losing the light fit to dust.
Efficacy: are they efficient? If the fixture is high efficacy or low.
-Relationship to natural light:
Fixtures close to window can have sensor to turn off-on automatically.
Lighting types:
Task light: lights that are for specific function, like study light in your desk.
Cove light: you will not see the fixture you will see the reflection. Ambient light. No glare no direct light aesthetic
Good for lighting up the space
Indirect light: sometimes we can cover with a piece of wall to hide the fixture and only get an indirect light , ambient light
Can, downright m: tend to have very direct light, clear line to indicate travel path. Architectural way to show the path. They are not great in lighting up the space. Not good for studying, because it shed shadow as well.
Recessed l: 2x4 or 2x2
They have some baffles between bulb and the space that bounce around the light and the result is more indirect light which is a god ambient light.
Pendant light: downward and upward or both. Hard to clean because it can be very dirty
Uplight : shed the light toward the ceiling then bounce from ceiling to down. Example: decorative art piece.
Sconce can be upward or downward or both.
Vanity: standing at mirror. Light that light up all of my face. It should not be from one side because it will creat shadow the other side. Multiple point sources. Line of lights
Surface light: the entire wall glow. LED is more spread out the light and better.
Outdoor lighting: cut-off lighting that keeps the sky darker
Zonal cavity methods for lighting
-Establishing workplane and desired foot-candles:
Office setting 25 to 50 - not more because we have computers
Surgery 300 500
Corridor 10
Garage 5 if it’s very high ceiling 15
Outdoor parking 2
The range for architectural uses is from 1 to 100.
-Gather all the information and start with a guess.
-Go through the calculation
-re-evaluate your guess
- go through the calculation again
-check to make sure that Iluminar is actually available.
determining the scale of fire protection system
Kitchen
Computer room
Pre-action
-Spacing: distribution for fire protection system in the ceiling is right above lighting zone. The distance between sprinkler system heads is between 12 feet and 15 feet.
When water comes out of the Springhill head and angle the gravity force it to come down and make a circle around each fire protection system. Then the 12 and 15 feet will be enough to cover the surface on their fire sprinkler system.
Is the head of fire the sprinkle is close to a column then the area beyond call Lim will not be covered by the fire. Sprinkle.
Column in this example is a blockage.
-Extra egress distances: sprinkler system will help you to have longer corridor for example, so we should be careful about blockages like column or partitions
-Wall washers: like a glass water: you will add wall washer (on both side of the glass wall) every 18” (for example) to wash that wall.
-sprinkler system ties into alarm system: there is little flow meter on all of these pipes and when the sprinkler system is pouring water l, the flow meter will realize there is a fire and it will go off.
—Specialty like kitchen computer reaction
Kitchen: water plus Grease you need to use chemical system but you can use water for some parts of a kitchen.
Computer room: you should care about taking the heat (water system), you need to take the oxygen away by foam system. Chemical system
Pre action:
For Museum not to damage the art pieces
Be careful, sometimes code says for a room 10’ x 20’, you will need only one head. But, you may not cover the corners, so you will need more head..
How can we design a fire system (sprinkler heads) to help fire fighter locate the fire?
Instead of having a continuous pipe , separate them in branches to have a fire alarm the beginning of each branches.
There will be a panel (in reception area in a hotel or multi family building) calls enunciator that shows which fire alarm is on. If we have multiple fire alarms for separated branches of pipes, identifying the location of fire will be easy for fire fighters.
STAND PIPES
Part of fire protection system
Probably next to stair well or inside the stair well.
Empty pipe that fire fighters in emergency time can connect their hose from fire hydrant (or fire fighters truck) to the stand pipe.
-Multi connections or Siamese connection: to double pressurize. They can connect two fire hydrant to one stand pipe to have more water with better pressure.
Stand pipe can use to charge sprinkler system directly too. Sometimes you have outdoor fire sprinkler in cold climate, so the entire pipe is dry and no water. In this situation you need to have a stand pipe only for fire sprinkler system. Or the other possibility is that the water of a fire sprinkler system is not an enough pressure.
Sometimes you have a tank in high elevation and you can use that water for stand pipe for fire protection system.
ELECTRICAL:
Circuit breaker
Kitchen circuit breaker
Insulation
We get the required electricity for our daily life from:
Plant
Transformer to step up
Tower for high voltage
Transform to step down
Typical telephone pole
Building
Transformer to step down
Weather head
Meter
Load center/electrical panel within a very few feet we will have like 5 or by 10 feet
For commercial project the panel can be outside within a few feet to the meter. Or very close to it. Smaller commercial and residential won’t have in exterior . When fire happens, fire fighter need to find the electrical panel first.
If you have exterior panel, that side means back of house. We can have underground conduit if you cannot have it on the building
When you get into building you have access to the panel
Some heavy use can be alone in circuit like HVAC and elevator system or oven .
Make sure we do not have all lights in one circuit , better to balance them.
Because it will be heave!
When we have too much power going through and it will heat up wires too much, and some wires will melt.
We use circuit breaker as a weak link,l that when it heats up, that disconnect and allow us the opportunity to find out what was the problem .
Circuit breaker protect the rest of wiring.
In the kitchen, we should not have all appliances on one circuit. We need multiple ones.
Residential : 15 amp to 20
For commercial : 15 to 20
Also much larger .
Power
Residential :
120-240
Or
120-208
Or
277-480
Insulation : if we have small wire that is been insulated very well, that wire will melt easily.
If the wire is larger, it needs more insulation.
At certain point, it’s better to use raceway instead of insulation
Conduit is hard raceway .
Suburban : No conduit . More flexible options
Urban: you have conduit.
It’s Safe ! Able to be modified !
In residential setting:
Outlet in different projects
In residential setting : we will have one outlet in each wall and max distance between outlets no more than 12’.( try not to overload a circuit and trip hazardous for people)
It means if we have a table lamp with 6’ cord, I must be able to plug in any place on the wall
Each door in residential projects should have outlet on both side.
In commercial projects:we don’t care about 12’
We use space differently, because each use is different in using outlets.
Residential: GFCI - detects water and cut off the power - wet locations
Bathroom
Basement maybe
Kitchen
Expensive
Arc fault : where? In bedrooms
Structure system
Bounce
Bridging/bracing
Shear walls
Buckling
Deflection
Column problem: buckling
Slab: compression/tension - deflection
Bouncing: fine for the roof - not good for floors (ductility) we want the structure kind of ductile but not too much that bounce.
Bracing/bridging: they use braces ( parallel to the beam on joists) at the lower cord of the joist. Why? Because joists are very light and start to squiggle.
Shear walls: to prevent lateral forces. Better to be symmetrical and from the first floor to the highest floor.
Steal
Glulam
Module of elasticity
Moment of inertia
The radius of gyration
Wide flange - when carrying a weight, start to deflect. The upper part of the deflection is COMPRESSION and the lower part is TENSION.
Neutral aces in the center.
The Glulam beam is made of a lot of layers (each 2x6) top 2 ones and the low two ones are structurally stringer. Because of tension and compression.
Material and shape is important when we are talking about structure.
The module of elasticity: material
It means the mathematical understanding of the robustness of that material.
When we are talking about shape, we are talking about moments of inertia, and sometimes the radius of gyrations.
Formula for deflection
5 w L 4 / 384 EI
W: weight
L: length of the span
E: material - steel is stronger than wood. E is going to be larger than the overall fraction smaller which means deflection (overall fraction) becomes smaller.
The deeper beam will be larger I -
I: moment of inertia ( deeper beam will have bigger I)
More load means more w means more deflection.
One way- Two way
One way: two bearing walls that joists are spanning between them - then decking on top of them
Singular direction between two bearing walls —-> one way system
Two way system: (concrete steel or wood) 4 Columns and slab on top of that.
Continuous:
If we have a beam than spanning over columns: between columns sag down and make a sinuses wave up and down. Above columns bending UP.
The nature of continuous beam make it not to deflect too much. If we cantilever the beam or slab a bit beyond the columns, the length of portion that sag down, will be shorter. Bend up part gonna be larger, so the sag part will become shorter.
One way - two way system examples
If we have columns in both directions, imagine 12 columns in 3 and 4 rows.
The girder will span between shorter span. Why? Because the girders have larger tributary area then the deflection will be more if the span is longer and longer. (A lot of structural issues unless we make the girders more robust !!) but beams are smaller and have smaller tributary areas and will not deflect that bad!!
Beam going to be spanned in longer direction
Then joists running between beams .
D
Then decking on top of them .
Girder—> beam—> joists—> deck
If we have beams closer to each other, then we will not need to have joists. Decking on top of them.
Girder—> beam—> deck
Two way structure : the concrete slab should have rebars on both sides
Moment connection
Pin connection
Diaphragms
friction
Moment connection: solid
Pin: can pivot around conceptually not in reality.
Assumption (not really like this) One single giant bolt of plate that connect columns to beam (for general movement, earthquake)
But if we have the plate welded to the beam and columns —> moment connection
Two pin connection: (triangle) bow out
One free connection and one moment:
Solid moment connection in both: now out but it first go straight then start bending because the connections are very strong .
Why don’t we have always moment connection? Pin is less expensive
Welding is expensive .
Moment connection are the best for lateral forces.
If we have bunch of connections, moment connections will be expensive. We can have all connections pin but then we can make some material in some bays like concrete and make it very stiff (shear wall). Combination of pin and shear walls instead of moment connections.
Or the second way, brace some of these bays!!!
Or we can have a few moment connections somewhere in certain locations and make it stiff. (Bracing does the same as converter shear wall )
Material for structures - Steel
Advantages
Disadvantage
Steel: hot rolled or light gage
But generally, when we talk about steel structure, it means hot rolled steel structure.
Wide flange: W12 x 40
12 : distance between lower and above plates.
40: pound per linear foot. (Direct relationship with cost)
W12 x 40 vs W12 x 100 ( more than 12 nominally because of extra steel)
Inner length are the same. More robust and thicker above and lower plates .
These wide flanges are way stronger when the load is perpendicular to aces
Wide flange or H as columns? More compact and chunky and now square.
We can use them for shoring as well.
Angle: 3x3x1/2
C channel: edging
Ts
American standard: AS
Steel has a good ductility : it will bend but it will bounce back to location,
Cast iron is not ductile, it’s brittle. M
Disadvantage: it melts
It should be fire protected . How?
Wrap with drywall, box it out.
Spray foam ( can be damage if somebody bump into it)
Tube: strong in x and y axes
The problem is when you want to bolt an angle to the tube, you cannot have the bolts inside the tube. You have go all through the tube.
Bar are solid tubes!!
Concrete
Site cast / pre cast
Beef-up
Plasticizer: like soap for more workability .No added water
Site cast: should be workable - flow is a huge issue - continuous element -
Precast: so much control
Any weather - individual element
Formwork for repetitive work
Very strong
Double t
Single t
Beef- up the concrete slab any where a column is connecting . Closer rebars
Anywhere we have tension, we need rebars (net)
Rebars are low in certain part of slab (between columns) and high in certain part of slab.
Welded wire frame : wires like net. Fabric for tension for avoiding cracks
Flat plate
Flat slab
Flat slab: stronger- for warehouses- for large buildings- Drop slab above columns - the bars go through slab ( like flat playe) but it has two slabs above columns - when it has mushroom caps, then it has even more space for rebar, stronger-
Flat plate: weaker. For offices Like columns’ bar goes to floors’ bar like my dad’s buildings
Buckling
Number of bars - 1/8 of a number
Stirrups
Why rebars are around outer part of a column? Tension is more there.
Number 3: connect between other stag or for slabs
They are thin
6 and8: for columns
14 and 12: for big commercial structure
Stirrups: for beams - denser around columns loading. Stirrups are like to wires.
Wood
Light frame
2x4
2x6
Timber :gluelam
Lumber
Dimensional lumber :
board:
1” :
1x10 and 1x4
2” :
2x4 - 2x6 - 2x8 …. 10 12
1 1/2 x 3 1/2
1 1/2 x 5 1/2
X 7 1/4
X9 1/4
X11 1/4
Timbers: any thing larger than 6”
Like
Knowledgeable people should make it
Fire will char the first layers of timber and then act as insulation. It doesn’t collapse for a long time.
Balloon frame
Platform
Balloon frame: we don’t have weak spot in the walls because they are consistent. But we do not have very tall trees to build taller buildings.
Not very good in fire
Platform or western framing: stronger connections between walls and slabs.
Easier to build than balloon.
Naturally fire stop.
Concrete foundation for light wood frame structure.
The surface of concrete foundation should be 8” above ground.
Why?
Wood absorb water and expand and contract
Pests, termite
Some rebars should stick out from foundation (actual name is anchor bolt) then the sill plate goes on top of and bolt on top of anchors( bolting sill plate yo foundation) , then we will have a rim joist that will sit in front of other joists. Joists for floor are usually 2x12 @16, then subfloor on top of joists. Now we have someplace on top of subfloor and on top of that stud (wall) - wall shearing will cover the stud from the upper line of concrete foundation to above. Then top plate above the stud. Then second top plate on top of first plate then Tim joists and regular joists again and subfloor etc.
Always better to have less wood in the wall.
What are some problems that we have to have the surface concrete foundation 8” above ground level?
We will have accessibility issues.
We can have the context issue(other buildings are on slab on grade).
Wall sheathing is part of structure
Sub flooring is part of structure
What nail is using for subfloor and sheathing
Can we use light wood framing for commercial projects?
True
True
Tie nailing
Yes, depends to the scale
Light frame wood structure
Stud walls (2) at the corner to be able to nail the sheathing to them
What is sill sealer? A piece that goes between sill plate and concrete foundation like cedar red wood (expensive) or treated wood ( however treated wood off glass)
Do we have other areas in building that we need treated wood or woods that is anti termite? Outdoor
Timber
Big challenge? Connections
What is the connection between a beam and 8x8 columns? We should make a hole in columns for beam. And curve out the end of the beam (to have a tooth) , After placing the beam inside the hole, we can use a drill to make a hole that goes through the columns AND THE BEAM . For a PEG. We can have my lipless pegs based on the structure
Or, we can use steel angle. Bolt in angle to the column then place the beam on top of the angle.
Tongue and grove flooring can span so long.
Split rings connector. Because the wood member can put a lot of tension on the bolt, we use split ring (2) between two members. Split ring and bolt should be installed there together. (Old fashion)
These days steel connections are better because they look good too.
Masonry
Self corbeling
Overlap half
When you have a very tall masonry wall the size of the lintel above a The window gonna be so thick. Better to corbel the bricks
Racked look of mortar
Efflorescence
Very beautiful and will make a shadow but the water will stay there and freeze and thaw…
The concave joint and singly strike joint are fine
Efflorescence is the action of brick when absorbs the water. Mortar will start soak and be filled with water, then start to evaporate back to outside. Water with minerals gets to the surface then evaporate and leave the mineral in surface.
CMU
Bond beam
8x8x16
Like CMU but when you fill it out with grout and rebates they act like beams. The internal hole is like a v and the external outline is like a regular cmu.
Beam
The most important force in a big am is tension and compression.
Chambering is a solution. Bend up then the weight will sag down (to flat)
Tension -compression
Wide flange steel: there a neutral axes above that is compression and below that is Tension
In concrete beam: above is compression and below is Tension (more rebars for lower part )
Do Do we have a neutral ax? Not like steel wide flange
If we need rebars for tension in a concrete bar, does it mean we don’t need rebars for the upper part of a concrete beam? We should have some rears for the upper part to avoid cracks.
What about wood?
The above part is compression and the lower part Is tension forces. Does it have neutral axes like a steel wide flange? No, the middle part just holds the other areas, so it can be thinner ( looking like a wide flange) in the I beam. But, we cannot thinner a 2x12 to have I bean. There should be three different elements.
Are all portions of a Glulam the same strength?
No! Above and lower are much stronger than the middle parts. (filler pieces)
Connections
Steel:
Moment and pin (shear) connection
Connecting the whole thing to the columns. Welding!!
At the moment connection, two elements ( beam and column) will be integrated together. The beam will transfer the force to the column. They will move together.
Pin connection: a bit of movement
The beam will connect to the web of wide flanges and some angels will be bolted to the Beam and columns
Or we can have angels on top and below the beam to the column (bolted)
Beam to girder condition
The girder is a bit deeper than the beam
If you have a moment connection for a girder and a beam, you can have a steel plate on top of the connection location (up flang )and then bolt or weld the plate to the beams and girder. And for lower flanges of the beam To the girder because if you have any questions plate on top of the girder then it’s not leveled for decking.
We can cut the web to create holes for piping, but not more than half of the width of the web
What if we have the beam’s lower flange on top of the girder’s top flange? The building gonna be taller, more expensive, and more material.
We need a stiffener for the bean above the girder. Welded stiffener or bolted and a stiffener for the girder below the Beam. Welded or bolted.
This option will give you more space under the beam for HVAC systems or plumbing.
Then above them, you will need metal decking for construction
-walk on it and do the process of construction.
-have a flat and strong layer which adds stiffness to the structure
Then we are able to pour wet concrete on top of it.
If the metal decking is perpendicular to the Beam means the decking Is beam to beam and there is no joist.
If we have a joist, the joist will span beam to beam and there is no need for metal decking to span the beam to beam. (it will not be perpendicular to the beam) , but still, we need to have a surface-to-span all over for flooring.
BECAUSE THE METAL DECKING HAS TO BE IN THE DIRECTION THAT IS SPANNING. Beam-to-beam spanning means that metal decking is perpendicular to the bean.
How do we install a metal decking to the Beam? Tack welding onto the beam down below.
Then concrete is to be poured above. (concrete topping or form deck) Concrete toppings are not functioning structurally. It’s just for leveling the surface for finishing. The metal decking is working structurally and the beams girders under.
If we want the concrete to ping to be structurally involved, a concrete slab will need rebars, WWF, etc.(composite deck)
Why should we use composite concrete decking above the beam and girders? Then we can use shorted beans and girders!!! Less expensive!!!
The metal decking for the composite concrete decking systems is different. It has some ridges in it to have more engagement with concrete Then concrete decking cannot slide back and force because it’s been hooked with decking through ridges. Make a female concept.
Bolts can be connected from composite to the decking if you want a very strong connection.
-What is cellular decking?
The same metal decking (corrugated deck), but we will have a flat material under the deck and nailed to it, now metal decking is stronger!!! Then you can use spaces between corrugated metal decking (cells) and a thin flat layer (thin gauge) for wiring. Cells!! ( you will not need to use concrete maybe!!)
Sometimes we have a wider metal decking ( the upper ones are wide and the lower ones are then): to have a broader and more surface without a lot of depressed parts for rigid insulation. Then walking on top of it will not break the insulation.
Light gauge steel structure
Cold rolled
Mostly for partitions
Can be structural too!!
Runner; the horizontal u shape runner that can easily screw down to the floor system. Slip system. Then you add studs on top of runners. Studcatecsimilar to runners, but has a little bit extra part to itself.
Stud: steel sheet that will be folded that has some holes for piping wiring. These kinds of studs are usually for partitions and not structurally. If it’s supposed to be structurally, then they will need to do bracing for each a few of them to avoid parallelogram over. Or adding blocking.
We will have some other squishy material under rubber that will block sound. When we are adding drywall we will leave some small gaps under there and fill it with sealant for sound!
Gauge number 14 is structural 12 maybe. 20 is for partitions. Higher number represent lighter and things studs.
Typical concrete details:
Foundation
Exterior supported structure like bearing wall.
It will sit in a foundation. (The upper corners which is 45 degrees angel of foundation do not do anything, they are just there to have a flat surface). Then foundation wall which can be CMU wall or grouted cmu wall or just concrete wall. Then 8” of this foundation wall should be above grade und level and then brick walls and air cavity and the back up wall (wood, steel, cmu, brick, etc)
The excavation line (bottom line) will not be exactly at the same level of the foundation line( the lower one), why? Because we need undisturbed soil. The above layer of excavated soil is disturbed so we use the undisturbed layers under that.
The concrete for foundation and foundation wall should be pouters in different days (28 days minimum)
Key: 2x4 - lateral forces from soil to foundation wall to slide it but they key act as a stopper. Then a rebar goes from foundation wall to the key and the foundation. We will have some rebars in foundation wall upper and lower parts to help the foundation wall to act like a beam and we will have vertically rebars (sometimes the vertical rebars can be outside and close to surface and sometimes they can be inside , depends on which side will be in tension and sometimes both sides).
The lower part of the foundation will have rebars or upper? Lower because lower will be in tension. Upper is in compression which does not need rebars.
Then we will have isolated slab on grade. It will have its own weld wire fabrics and help with some cracking.
And there will be some material between isolation joint, this material should be able to expand and contract. It will be a bong breaker between foundation wall and slab. They should not be connected to each other and it will help to stop moisture as well.
And under the slab we need vapor barrier to stop the water coming from the soil due to hydrostatic pressure. This vapor barrier should sit on crushed stone to avoid the hydrostatic pressure.
Hydrostatic pressures coming laterally from side. We will need gravel there on the side of foundation wall where the pressure will be. The gravel will sit on foundation, it’s better to cover the foundation surface and foundation wall with clay! We will have drainage mat on the foundation wall and push the water down then we will have an insulation between foundation wall and drainage Matt.
We will need a profferrated pipe next to foundation to flow the water out to the surface of ground label or drain tile connect to the sump pump and sump pump wall take it into the building and then to sewer system . If there is storms were it can be go there. Some places have both system and some have only sewer system. Or sometimes those perforated can act like reservoir and hold the water for a while then sip into soil and ground water.
Or we can have a layer of clay right near the building perimeter to help us the water to drain the water away from the building or sloped . Do not have vegetation very close to the building.
What is Capillary action?
When we have two surface that are very close to each other, when water goes through it will be propelled through from one side to the other side of the surfaces.
What should we put there? What materials can be capillary breaker?
Bentonite Clay
Dumbbells
Damp proofing systems
Pre cast design
Hollow slab can span? 40
Double Ts? 70
Precast beam and columns:
Columns should be in a shape to hold beams. We should have other stuff connected to the precast columns and beams to be able to work together. We can have thin and hollow pre cast concrete slab above beams. These hollow concrete slabs are connected to each other by rebar and grout and a thin layer of concrete on top of all of them to have a flat surface. At the end we will have rebars going to different directions
Prefabricated beams sometimes are L shape (smaller leg) to carry the prefabricated slabs or Ts .
We will not have custom shape if we want pre cast concrete elements but we can have any shapes when we have cast in place concrete.
Why hollow? To reduce the weight
Masonry design issues
Structure
CMU wall:
Running bond, half laps.
Grout the holes and add rebar. Then we will have some reinforcing in the bed. Horizontally and vertically.
This horizontal and vertical reinforcing protect the CMU was from bowing out or buckling. At the end we will call it concrete wall \ masonry structural wall.
Bond beam: the u shape block the filled out with rebars and grout and it will act as a beam. Span over opening or doors.
What if we have a CMU structure wall which should carry a steel beam or timber beam? We can have a cavity inside the CMU wall which will have steel plates to connect the beam to the wall.
If we have timber goes into the cavity of CMU, we should have a fire cut.
Fire cut is when we cut the corner of the timber beam cut in angle because if beam is in fire it will goes up and put pressure under the cmu in cavity and it can break the cmu wall.
Be careful putting timber inside a cavity of a cmu wall.
Masonry is wall - control joint
Wherever we have a steel angle above windows that will create an horizontal control joint. Then sealant under the steel angle.
What about vertical joint?
Cracks tend to be on the corner on the windows. So it’s better to have expansion joint on corners. Control joints are only for the brick veneer.
If the wall is very long then we can have a couple of expansion joints too.
Expansion joints will be all the way through a wall.
Control joints are not all the way through the wall, they are for brick veneer only to encourage the crack to happen there.
When we have an expansion joint, we will have a piece of object there .
Light wood structure - Cool Roof
Rafters on top of double plate then to have ceiling first we need to have some beams that span between columns and they will be above double plate. The suffix out side will have some holes for vent to make it a cool roof.
In cool roof (because the suffix has vent and make the entire roof cold) we will have snow on entire roof which will work as an insulation.
What if we do not have vent in soffit ?
Then the roof will not be a cool roof and snow on some part of roof (middle part) will thaw but not on the edges. Then the snow keeps melting on the middle part which is not good.
What if we have a cathedral roof? Then because we need to insulate the entire spaces between rafters then we will not have a vent. We should leave some space called baffles for venting and insulate the rest of roof.
Cool roof works is summer as well.
2 by woods for flooring and roofing. What else’s we can use for roofing?
Trusses. We do not have to cut bird’s mouth cut. They sit nice and flat. Trusses are @24”.
You will not have attic using trusses unless you use scissor trusses.
What if we have light wood frame structure but we need 25’ spanning.
12” trusses issues
Typical spanning for light wood frame is by 20’. If we want something broader, we can use TJI (wood I beam).
Much stiffer that 2 by 12 14 ..
It’s made up (2) block of wood attaching to OSB or piece of wood that separate them together.
Or trusses. 2 (2x4) up and down and then using 2x4 on angels. At the middle you can have open area for duct work. Why middle? Because there is a neutral axes.
12” Truss will have very small triangle. Try to use 14 or 16 even if 12” is sufficient.
What is the disadvantage of Rim joist in light frame structure?
Rim joist are in direct touch with sole plate above and double plate down. Rim joist will expand and contract and this will cause issues.
The rim joist for trusses are much smaller because they only cover the upper part of truss. (For the shape of truss)
Wood light frame design
Headers and lintels
The two main studs on left and right sides of an opening , is called king stud, then you will have a Jack stud next to it and inside the window from floor to upper level of opening.
Then we have a header which is sitting on Jack stud. There is a sill on lower level of the opening which will be held by another Jack stud. (A lot of wood yikes!)
Then we will have the shorter studs under opening and above the opening (use to be called cripple, but now they call them short stud or Jack stud)
How is made a header? Section: for example (3) 2x8 and a layer of plywood between them.
Does header have insulation? NO! Is there any solution? We can have (2) 2x8 and (1) 2x8 on top of it horizontally. Then infill between 2x8 s by rigid insulation. Sometimes you can make a box. (There are a lot of ways to think about that)
Size of boards for headers
For typical 3’ window we can use 2x6 and maybe a layer of plywood between.
For larger window to span larger we will need 2x8 or even bigger.
If we need the header to be very strong, piece of steel will be added to the wood pieces to make a flitch plate.
Flitch plates are when we use sheets of steel or plywoods or both in our beam header design.
Typical timber frame
Connections are very important in timber structure. Sometimes we need moment connections. To do so, We will need steel connectors
Or we can use cables. Bracing with cables.
What will we use for sheathing in timber structure?
One way: Purlins! Going through long distance. And it’s not structurally but it will add some stiffness.
Another way is using stress skin panel: They are plywood or OSB with styrofoam interior and another layer of plywood. It has some holes through it at some certain heights for electrical conduit. Why do we call them stress skin panel? Because the entire weights will be on plywoods. You can build the entire a house with stress skin panel.
How do we connect two panels? It’s like CMU (when you put them next to each other there will be a gap between panels, add a wood block there and nail it to the panels.
Size: 4’ 8’ etc that wood blocking can act as a thermal bridge. But when we have 8’ panels, it means that we will have that wood blocking every 8’ which is very good.
Downsize? Transportation z
And you need to use crane if they are large.
Very sustainable
Acoustic
STC
How can we have 100% acoustic? When we separate them structurally
STC focus a on human voice.
Issues:
The structure is continuous
Different materials have different impacts.
Outlets
Lighting fixture
Etc
Solutions:
-Sealant at the bottom level of plywood and all edges of plywood
-don’t put the outlet back to back
-multiple layers of drywall
By doing these solutions we probably can have STC 50.
How can have a higher STC?
-Two different walls next to each other (STC:55)
I’d we double up the plywood and remove the inside layers of plywood and leave some air gap, then it will have the best STC (STC:58 , very good for human voice)
-resilient channel
NRC: depends to the material of surface and if it has holes or not. If it can absorb some sounds.
NRC can be complicated in large rooms not small rooms.
NRC: the size of the room and the material of surfaces
In some rooms we need to reflect the sound. We like it! Like live room. (Music) not too live! A bit bouncy and vibration. Or like restaurant (people like sound )
Dead room (studio to record)
Noise reduction coefficient between zero and one
NRC : zero
Materials like concrete, glass, very dense materials that will bounce the sound entirely. (The reflected sound does not distribute, it is one reflected sound which is very strong)
NRC: one absorb all sound
NRC of ceiling panels something between .5 and .6 . This means it can reflect one sound to multiple reflected sounds and make it less strong and you will hear a whisper !
In very large rooms like a venue for opera, we need to use acoustic materials for surfaces to absorb and reflect the distributed sound (white noise) otherwise we will hear very strong sound (directed sound from concrete) and it will be so annoying
Small room acoustic
Large conference room
Small room reflect the sound so fast and you hear that as one sound. So it’s easy to control the sound acoustic in small rooms.
But in large rooms it takes longer for sound to reflect back to you. A sound can reflect one time to another surface then reach to you because it’s a large room. You will hear a sound twice.
Alarm system
Emergency system
Emergency generator is required for some building do you want 
Emergency light is for when power goes out. To help people find their way. There is no switch for emergency light, it’s a hard-wired light all the time. They are on all the time.
More for office setting institutional setting .
They will be on their own circuit and they stay on. Sometimes these lights are connected to a separate generator and they will stay on for a looong time with other stuff. Like water pumps lights in lobby…
Importance factor - I factor
You find I factor under structure and other calculations. Those building will likely be required to have emergency generator. Sometimes insurance will require you to have backup generator .
Herd wired emergency lights
In a few locations, in the corridor, or in lobby. In some situation you can have all the lights on emergency line.
We will have one light in each space, not necessarily each tiny office space in a large office , but in each tenant space. Maybe a couple light per floor .
Alarm system and strobe
Smoke detectors detect smoke detect a problem and send it to centralized system (Alarm system) and alarm system send it out to strobe and other system.
Strobe for people that cannot hear. Occupied rooms should have one .
Pull station system
How do you know where to locate pull station?
Fire extinguishers
A system that allow people inside the building to let everybody know there is a problem in the building. It’s a little red box with a leveler.
It should be located somewhere very obvious like right next to entrance or in the lobby and Right in egress path!!! . People should have a sense that where they can find it.
Fire extinguisher:
It depends on:
-Occupancy type
-Construction type
Who are occupants? Kids? Adults? Elders?
Is the structure of the building vulnerable? Construction type!
They should be located in obvious locations. Near exit stairs , in the egress path.
Fire extinguisher
General ones are every where like what we add to our projects.
The other ones for specific use are A B C D
A: gas , liquid
B: paper, wood, plastic
C: Electrical components
D: metal
Kitchen: using water base fire extinguisher is dangerous here.
Mechanical room: not water base - foam base
Intercom system
Audio system that will hav e speaker some area like stair(very important location for interview) , area of refuge , lobby .
People that are stuck in stair wells or area of refuge will need a system to let the security or receptions or others (front desk) know that they are there. Or at least a button to insert and alert other people.
Area of refuge:
Communication system should have.
Area of refuge should be outside of travel of path. Floor clearance :30x48
Travel path in stairs landing is a curve which starts from the end point of thread to the endpoint of the next step. (100% travel path formula)
The door’s swing line should not be inside the travel path of landing.
There should be an intercom (two way communication system) in area of refuge.
If you need to move the area of refuge out of stair well to have it’s own area, it can be larger that 30x48.
If you are tucking this area into a wall to be parallel: 30x60
