Ch.13 Mechanical and electrical systems Flashcards
What does HVAC stand for
Heating ventilating an air conditioner
What is used to heat or cool a building
Air or water
What type of systems cooler heat Spaces by conditioned air alone. He is transported to the space for supply and return air ducts.
All air system
How does a residential forced hot air furnace work
A boiler powered by oil or gas heat distributed throughout the house and duct work. Return air ducks in each room collect the cold air and return it to the furnace for reheating. If necessary, and air-conditioning is connected to the same ductwork to provide cold and dehumidified air
What are some of the year oh air systems in commercial construction
Variable air volume VAV, High velocity dual duct, constant volume with reheat, and multi zone systems.
The space between the suspended ceiling and the structural floor above
 plenum
If I were to partition 16 above this has been at ceiling, they supply air ducts and openings for return air must be provided. At the locations where the firewalls penetrated what is required
Fire dampers
These heating systems use some type of coil unit called a contractor and each space through which hot water circulating. The hot water heater fan of the coil unit, and the air is heated as it dries over the fence. There may be circulated by convection, as with most baseboard residential Finn to radiators, or buy for circulation created with a fan.
All water heating system
Combination systems that you don’t work to supply fresh air but water to heat and cool the air before it is introduced the conditioned space.
Terminal reheat systems
Where did small ducks in plumbing pipes run in residential design
Within the wall and floor joists
What is wrong with in the walls and floor joists in residential construction
Small ducts and plumbing pipes
Where are horizontal ducks normally run in commercial construction
Plenum
Where are vertical ducts normally run in commercial construction
In their own chases 
And enclosed vertical space used only to accommodate ducts or pipes. In multi story buildings these run continuously through floors.
A chase
This is located in the Plenum and it adjusted quantity or temperature of air going into a space from the main air supply lines, reduces the velocity of air, and attenuates noise. This is also called a VAV box and it is typically placed above the ceiling within or near the space it serves
A mixing box
What type of system do mixing boxes actually mix cool in hot air coming into it from two separate ducks and distribute the mix air into ducts serving individual rooms in spaces
Dual duct system
Within these types of systems the box contains a hot water coiled provides additional heat to the airstream. These can easily be identified by the air ducts and copper pipes leading into them.
Terminal reheat system
What are the typical sizes of mixing boxes
Mixing boxes can range in size from 6 inches to 18 inches high, 24 inches to 60 inches long, and 14 inches to 66 inches wide.
Are mixing boxes easy or difficult to move? Expensive?
Difficult and expensive
What is the best way to confirm the location of the HVAC, plumbing, electrical, and fire protection services?
Going on site and viewing the space above the ceiling
False floor of individual panels raised above the structural for with pedestals. Most commonly used to accommodate electrical, communication, and computer wiring, but it can also be used to provide space for some types of HVAC ductwork. The ductwork serves individual workstations.
Access flooring
Consist of two runs of studs separated by several inches, the exact dimension being determined by the largest pipe or duct that Hass to be concealed. Only the finish side of each run of studs is covered with wallboard. These walls are commonly used between back-to-back commercial toilet rooms where extensive plumbing work and toilet carriers are required.
chase wall
A steel framework that is bolted to the floor inside a pipe chase and carries the weight of the wall hung toilet
Toilet carrier
Infomercial construction him wear a Plenum is used as return air space what does building code prohibit
The use of Combustible materials such as wood or exposed wire
In some cases when required by the local authority having jurisdiction what must be installed to limit the spread of fire and smoke horizontally? Normally these are simply an extension of the fire rated partition.
Fire rated dividers
Describe the upper most layer of the Plenum in a steel structure
Require deep girders and intersecting beams with a few inches of fire proofing.
Describe the upper most layer of the plenum concrete construction
The space needed can vary depending on the framework
Where are mechanical ducts, mixing boxes, and other HVAC requirements usually located
Below structural members
What is the depth of the Plenum usually determined
By the depth of the largest duct that runs below the deepest steel girder or a concrete beam
What is usually located below the ductwork
Sprinkler and plumbing piping
How much space to sprinkler and plumbing piping typically need
4 to 6 inches of vertical space
What constitutes the lowest layer of the Plenum
Lumineers
How much space is typically required for Lumineers
9 to 12 inches depending on the type of fixtures chosen
How much space is required for the depth of the suspended ceiling
2 inches however, there must be an additional space to allow installers to tip the tile when installing the ceiling
Typically small seal doors with frames that are open by using thumb turn or a key. If required these are available as fire rated assemblies. They provide access to certain mechanical and electrical systems in gypsum wallboard ceiling
Access door
Where are thermostats typically located
Away from exterior walls, heat sources, or other areas that personally affect their operation. They are normally located 48 inches above the floor, but they should be coordinated with light switches and other nearby wall-mounted control devices.
How much space should be between glass and any window covering to avoid excess heat buildup in commercial construction
 2in
When an office wall intersects an exterior wall with a convector running near the floor and the convector allows warm air to circulate it also allows sound to penetrate and travel inside the contactor past the partition and out the opening on the other side. How much should a conductor be modified to prevent this
Cutting the convector or piping which is difficult and expensive or about using sealant inside the convector and still allowing the hot water pipe to run continuously.
These can be used when the appearance of the air distribution device needs to be minimized or when the available space does not allow for a square diffuser. Is diffusers are long and narrow and contained from 2 to 8 spots, resulting in a finish opening of about 3 to 8 inches in width. They can be purchased in any length and use for either supply or return air.
Slot air diffuser
Where are slime diffusers typically used
In wallboard ceilings
Any type of system that conserves energy in HVAC
Displacement ventilation
What do single lines represent on HVAC drawings
Piping or duct work
Ducts are notated with a line and a number what do the first and second number represent
The first number represents the width in inches and the second number represents the height in inches
Supply air register with device indicator with dirt size in CFM indicator
Return air grill with indicator device
Linear slot diffuser
Supply air duct width size, width x height