Term
| Mechanical systems include |
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Definition
| heating & cooling, plumbing, and fire protection |
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| Electrical systems include |
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Definition
| power, lighting, telephone, and other communication systems |
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| designer is not responsible for |
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Definition
| designing or producing construction drawings for structural, mechanical, adn electrical systems. must know when/how to coordinate consultant's drawings. |
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Definition
| heating, ventilation, air conditioning, and includes all the systems used for these purposes. |
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| HVAC systems are often classified by |
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Definition
| medium used to heat or cool the building. two primary methods of heating and cooling use air or water. |
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Definition
| cool or heat spaces by conditioned air alone. heat is transported to the space with supply and return air ducts. common example being residential forced hot-air furnace. |
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Term
| commercial systems utilize |
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Definition
VAV-variable air volume, high velocity dual duct, constant volume with reheat, adn multizone systems.
all types require supply air ductwork, registers, adn return air grilles in all spaces.
registers are connected to the supply air ductwork adn can be adjusted to control the direction of air flow and the volume of air coming through them.
in many instances, separte ductwork is not used for return air, but grilles are simply placed in the suspended ceiling to collect return air. mechanical system then draws the return air back to a central collecting point where it is then returned through ducts to the building's heating plant. |
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Definition
space between the suspended ceiling and the structural floor above.
if fire-rated partitions extend above the suspended ceiling, then air supply ducts and openings for air return must be provided.
at locations where the fire wall is penetrated, fire dampers are required that automatically close in the event of a fire. |
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Term
| supply air registers are often connected |
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Definition
to the main ductwork with flexible ducting. this allows some adjustability in the exact location of an air register if its location is in conflict with some other ceiling mounted item.
return air grilles are generally not connected to ducts in commercial construction. |
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Definition
all water heating systems use some type of coil unit called this, in each space through which hot water is circulated.
the hot water heats the fins of the coil unit, and air is heated as it is drawn over the fins. air may be circulated by convection, as with most baseboard residential fin-tube radiators, or by forced circulation created with a fan. |
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Definition
| combination of systems that use ductwork for supplying fresh air but use water to heat or cool the air before it is introduced into the conditioned space. |
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Term
| in geographic areas where electric heat is economical |
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Definition
| radiant panels can be mounted in the walls or created by running cables in the ceiling. electric panels are also used where it is necessary to avoid drafts. |
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Term
| in commercial construction |
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Definition
| horizontal ducts are normally run in the plenum and vertical ducts are normally run within their own chases. |
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Term
| another consideration when planning ceiling layout is |
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Definition
location of mixing boxes, which are also located in the plenum. a mixing box adjusts the quantity or temperature of air going into a space from teh main air supply line(s), reduces the velocity of aire, and attenuates noise. lines from thermostats are connected to mixing boxes.
with variable air volume systems, the VAV box varies the quantity of air. VAV box is typically placed above the ceiling, within or near the space it serves. |
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Definition
| the mixing box actually mixes cool and hot air coming into it from two separate ducts and distributes the mixed air to ducts serving individual rooms or spaces. |
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Term
| with terminal reheat systems |
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Definition
| box contains hot water coil that provides additional heat to the air stream. |
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Term
| verifying the size adn location of duct-work, mixing boxes, adn piping before locating light fixtures and other recessed ceiling items |
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Definition
can be found in HVAC plans, consulting with the mechanical engineer, or by visual inspection.
on-site viewing of the space above the ceiling is the best way to confirm the location of existing HVAC, plumbing, electrical, adn fire protection services. |
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Definition
| false floor of individual panels raised above the structural floor with pedestals. most commonly used to run electrical, communication, adn computer wiring, can be also used for some types of HVAC ductwork that serves individual workstations |
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Definition
two runs of studs separated by several inches, the exact dimension being determined by the largest pipe or duct that has to be concealed. only the finish side of each run of studs is covered with wallboard.
chase walls are commonly used between back-to-back commercial toilet rooms where extensive plumbing work and toilet carriers are required.
toilet carrier-steel framework that is bolted to the floor inside a pipe chase and carries the weight of wall-hung toilets |
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Term
| in commerical construction when the plenum is used as a return air space |
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Definition
| building code prohibits the use of combustible materials such as wood or exposed wire within the space. |
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Term
| building codes require that access be provided to certain components of mechanical and electrical systems |
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Definition
| include valves, fire dampers, heating coils, mechanical equipment, electrical junction boxes, communication j boxes, and similar devices. |
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Definition
| typically small steel doors with rames that are opened by using a thumb turn or key. available as a fire-rated assembly if required. |
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Definition
| location usually determined by the mechanical engineer so they are away from exterior walls, heat sources, or other areas that may adversely affect their operation. |
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Term
| desinger should coordinate |
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Definition
location of supply air diffusers adn return air grilles with other ceiling items such as lights, sprinkler heads, smoke detectors, speakers, and the like, so the ceiling is as functional and well planned as possible.
mech. engineer must be consulted to ensure the desired types and locations of supply and return air devices do not adversely affect the operation of the HVAC system |
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Definition
designer should have the mech. engineer or architect check that the proposed size, type, adn mounting will not create a problem with the HVAC system.
should be at least 2" between any glass and window covering to avoid excessive heat buildup, which might cause glass to crack or break. |
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Term
| in commercial construction |
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Definition
| most HVAC systems are designed to work independently of partition relocation and furniture placement. in some cases, HVAC zones are designed for one layout and many not work with the desired zoning of a new plan. |
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Term
| mechanical and electrical services often pose problems with |
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Definition
maintaining accoustical separation.
special detailing or construction may be required to create a continuous sound seal around the floor, around the ceiling, above the ceiling, adn along the perimeter wall.
cracks between wallboard and all pipe and duct penetrations must be sealed with an acoustic sealant. |
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Term
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Definition
when an office wall intersects an exterior wall with a convector running near the floor. openings in the convector that allow warm air to circulate aslso allow sound to penetrate and travel inside the convector, past the partition, adn out the openings on the other side.
convector must be modified in some way to prevent this, either by cutting the convector and piping (difficult and expensive) or by sealing inside the convector while still allowing the hot water pipe to run continuously. |
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Definition
| with a line and a number such as 18x12. first number indicates width of the duct in inches, and the second number indicates its height in inches. |
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Term
| electrical systems include |
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Definition
power for lighting, convenience outlets, and fixed equipment.
electrical engineer or electrical contractor designs and specifies the exact type of circuiting, wire sizes, and other technical aspects of the electrical systems. designer is responsible for schematically showing desired location of outlets, and switches, where power is required for special built-in equipment, and the appearance of cover plates and other visible electrical devices. |
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| several types of conductors that supply power throughout a building. |
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Definition
| extend from circuit breaker boxes to the individual switches, lights, and outlets. |
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Term
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Definition
| nonmetallic sheathed cable, which consists of two or more plastic-insulated conductors and ground wire surrounded by a moisture-resistant plastic jacket. can be used in wood stud residential buildings adn buildings not exceeding three floors, as long as it is used with wood studs adn protected from damage be being concealed behind walls and ceilings. |
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Definition
flexible metal-clad cable, consisting of two or more plastic insulated conductors encased in a continuous spiral-wound strip of steel tape.
often used in remodeling work because it can be pulled through existing spaces within a building. also used to connect commercial light fixtures so they can be relocated in a suspended acoustical ceiling. |
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Term
| for commerical and large multi-family residentail construction |
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Definition
| individual plastic insulated conductors must be placed in metal conduit or other approved carriers. conduit supports and protects wiring, serves as a system ground, and protects surrounding construction from fire if the wire overheads or shorts. |
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Term
| outlets and other types of connections to the power supply must be made in |
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Definition
junction boxes. steel or approved plastic boxes to which the conduit or other cable system is attached.
several can be connected if there are more than two switches or two duplex outlets.
also required where light fixtures are connected to the electrical system. |
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Term
| building code specifys requirements for outlet locations |
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Definition
| in residential construction, outlets must be no farther than 12' apart, and where there is a duplex outlet on each wall surface where furniture might be placed so lamp cords and the like are not stretched over door openings. |
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Definition
special power outlets that must be placed on their own circuit. prevent various types of electrical interference from disturbing sensitive electrical equipment connected to them.
must be clearly identified on the plan, as well as circuits that require more than 120 volts.
inclusive of electric ranges, clothes dryers, large copy machines, and other special equipment. |
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Term
| in addition to the protection provided by circuit breakers in the panel boxes that trip off if the circuit is overloaded, there are two types of protection provided in electrical wiring. |
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Definition
1. grounding-separate wire in addition to the two that provide power. grounding of an electrical system prevents a dangerous shock if someone touches an appliance with a short circuit and simultaneously touches a ground path such as a water pipe. the ground provides a path for the fault.
2.ground-fault-can create problems because the current required to trip a circuit breaker is high and small leaks of current can continue unnoticed until someone receives a dangerous shock or a fire develops.
(GFI's) ground fault interrupters are devices that detect small current leakes and disconnect the power to the circuit or appliance. required for outdoor outlets and in bathrooms, basemetns, adn kitchens, as well as other locations specified in teh National Electric Code. |
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Term
| telephone and communication systems are usually shown on |
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Definition
the same plan as the power outlets. designer is responsible for showing the location of items like telephones, intercommunication systems, public address speakers, buzzers, computer terminals, and similar equipment.
actual circuiting, wire sizes, adn connections to central equipment are usually determined by the electrical engineer or the contractor responsible for installing the equipment. |
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Term
| because telephone adn communication systems are low-voltage |
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Definition
the requirements for conduit and other protection are not quite as stringent as for high-voltage power. in many cases, an outlet box is provided at the connection in the wall, and the wire is run within the walls and ceiling spaces without conduit.
in some commercial construction all cable is required to be protected in conduit to avoid having it catch fire or release toxic fumes in case of a fire. |
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Term
| designer can locate electrical, phone, adn communication outlets on one of several plans |
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Definition
residential construction-often shown on the construction floor plan b/c installation is fairly simple.
on commercial, separte power plan is usually used. in addition to showing outlets themselves, exact dimensions are given if location is critical. |
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Term
| plumbing systems consist of two major components: water supply and drainage |
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Definition
| water supply includes cold and hot water. in all plumbing installation, water is supplied under pressure to individual plumbing fixtures. b/c of this adn b/c the pipes are generally small, it is relatively easy to lcoate pipes within wall cavaties, ceiling structure, and other areas to supply a fixture, even if it some distance from the main source of water. |
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Term
| drainage systems work by gravity |
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Definition
| drain pipes must be sloped downward to carry away wastes. in addition, vent pipes are required. |
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Term
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Definition
located at every fixture and are designed to catch and hold a quantity of water to provede a seal that prevents gases from teh sewage system from entering the building.
traps are not installed where fixtures include traps as an integral part of their design, such as toilets, and where two or three adjacent fixtures are connected, such as a double kitchen sink. |
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Term
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Definition
to the actual drainage piping, but they must also be connected to vents.
vents-pipes connected to the drainage system at various locations, open to outside air, adn deisigned to serve two purposes.
1. allow build-up sewage gases to escape instead of bubble through the water in the traps
2. allow pressure in the system to equalize so discharging waste does no create a siphon that would drain the water out of the traps. |
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Term
| from the trap, sewage travels in fixture branch lines to a vertical stack |
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Definition
| if the stack carries human waste from toilets, it is called a soil stack. if stack carries wastes other than human, it is known as a waste stack. |
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Term
| vents from individual fixtures are connected above the fixtures in two ways |
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Definition
1. if a vent connects to a soil or waste stack above the highest fixture in a system, teh portion of the stack above this point is known as a stack vent. the stack vent extends through the roof.
2. in multistory buildings, there is a separate pipe used for venting. this is called a vent stack, and either extends through the roof or connects with the stack vent above teh highest fixture. |
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Term
| if a pipe must be concealed within a floor space |
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Definition
| then the slope and size of the pipe itself will limit the distance from the fixture to ta connection with a riser. |
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Term
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Definition
| areas, usually at structural columns, where hot and cold supply and drainage risers are located. |
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Term
| plumbing chases are constructed |
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Definition
| with two sets of studs with a space between large enough for the pipes |
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Term
| most common types of fire protection: sprinkler system |
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Definition
sprinkler heads are available in recessed, upright, pendent, and sidewall
recessed-smooth cover that is flush with the ceiling. when there is a fire, the cover falls away and the sprinkler head lowers and activates
upright-used with exposed plumbing and high, unfinished ceilings
pendent-traditional types for finished ceilings, but the head extends a few inches below the ceiling.
sidewall-used for corridors and small rooms wher one row of sprinklers will provide adequate coverage for narrow spaces.
horizontal sidewall-can be plumbed from the walls instead of from the ceiling, which makes them good for remodeling. |
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Term
| sprinkler pipes above the ceiling |
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Definition
| require additional space that may interfere with recessed lighting and other ceiling construction. |
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Term
| design and install of a sprinkler system |
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Definition
governed by local building code, but most refer to standard published by national fire protection association NFPA-13. places fire hazard of buildings into three groups:
1.light-residences, offices, hospitals, schools and restaurants (must be one sprinkler for every 200 sq.ft)
2.ordinary
3.extra hazard
max. spacing between sprinkler heads is 15 feet for teh 225 sq ft requirement, with the max distance from a wall being one half the required spacing. |
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Definition
| gas, released when the system is triggered, that smothers the fire while allowing people in the space to breathe. |
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Definition
| includes stairs, elevators, escalators |
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Term
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Definition
portion of egress achieving a change in elevation by means of a single riser.
stairway-change in elevation having two or more risers
flight-series of two or more risers between one floor or landing and the next.
landing-flat portion immediately adjacent to either the bottom or top of a flight of stairs. landings must be as wide as the stairway they serve.
new IBC does not have a definition for "step" and defines a stair as one or more risers |
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Term
| most common configurations of stairways |
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Definition
straight runs, either in a single line, L-shape, or U-shape
three special types of stairways: winding, circular, and spiral
winding-tapered treads that are wider at one end than the other.
circular-sides whose shpae is a circular arc. the inside, or smaller arc, cannot be less than twice teh width of the stair. if it is, it's considered a winding stairway.
spiral-wedge shaped treads that radiate from a center support column
winding, circular, and spiral stairways can only be used as exit stairs in private homes and in provate stairways of apartments, condos, and the like and only if they meet special requirements.
IBC states they are also allowed, if they are NOT a required stair |
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Term
| height of riser and length of tread |
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Definition
generally, height of riser must be determined first, so each riser between is identical within min and max code limitations.
2R + T = 25
for most stairs a 7-inch riser and 11 inch tread is a good combo.
min tread width by code is 11"
if riser height must be modified to equalize stairs between fixed floor height, dimension between 6-7 " should be used.
nosing-usually extends about an inch from the back of the tread. |
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Definition
| represents a steel column if seen on a floor plan, but it represents a beam if viewed in a verctical cross section. |
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Definition
loads from above. include live loads, such as people, furniture, and snow, and dead loads, such as the weight of the structure itself.
bearing walls can only be pierced for doors adn other openings if the top of the opening is framed with an adequately engineered lintel or beam. |
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Term
| in residential construction |
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Definition
exterior walls are usually bearing walls. the first-story of a two-story house are nearly always loadbearing.
if a wall needs to be cut for a moderately sized opening, it is relatively simple to have additional studs installed with a double header or other type of lintel. |
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Term
| in commercial construction |
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Definition
fewer bearing walls are used than in residential; most structures are some form of column-and-beam system with nonbearing infill. core walls of high-rise building are nearly always structural and cannot be pierced except for small openings for pipes.
in smaller commercial buidlings, concrete walls and many masonry walls are bearing. |
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Definition
| includes weight of people, furniture, and other moveable equipment. |
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Term
| in addition to determining max allowable loads, floor construction may limit the number and type of floor penetrations |
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Definition
| including minor items such as a core drill for an electrical conduit, to major items such as reconstruction for stairways. |
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Term
| floors in commercial buildings are constructed |
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Definition
| primarioly of poured-in-place concrete, precast concrete, or concrete on metal decking. |
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Term
| poured-in-place concrete floor systems can be pierced for small openings such as floor-mounted electrical box. |
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Definition
however, holes cannot be cut where the columns intersect the floor or where beams are located.
for larger openings, easiest types of concrete floors to cut are flat plates and flat slabs. however, large openings, these floor types still require additional structural support around the opening, which must be designed by a structural engineer.
ribs of waffle slabs can be cut for large openings, such as stairways, but this is difficult and also requires additional support to be placed around the cut. |
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Term
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Definition
consists of factory-made pieces. high-strength steel cables are stretched in the precasting forms before the concrete is poured. after concrete attains a certain min. strength, cables are released and they transfer compressive stresses to the concrete.
precast concrete floors include single tees, double tees, and hollow core slabs. columns and beams can also be precast. |
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Term
| b/c stems of tee sections are deep and contain prestressed cable |
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Definition
they cannot be cut, so openings are limited to the areas between the tee sections.
for hollow-core slabs, small openings can be cut through the existing cores but should not be cut through the solid portion where teh prestressing cables are located. |
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Term
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Definition
| in this system, post-tensioning stell (called tendons) is stressed after the concrete has been poured in place and cured. b/c they are stressed under high pressure and keep this stress during the life of the building, the slabs in which they are located cannot be cut. |
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Term
| one of the most common types of floor adn roof construction is |
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Definition
concrete on metal decking. corrugated sheet steel is supported by steel beams and columns and serves as a working platform, the form for the concrete, and part of the structural system. concrete is poured over teh decking and leveled to create teh final rough floor.
fairly easy to have moderate sized holes for conduit, ductwork, etc. if larger penetrations are required for stairs or elevators, steel angles or beams can be placed around the perimeter of the cut to provide the necessary reinforcement. |
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Term
| interior partitions in commercial construction that attach to the structural floors above and the perimeter of teh building |
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Definition
should be designed with slip joints to allow the buidling to move slightly without putting pressure on the partitions. partitions rigidly attached to the structure may buckle and crack if this is not done.
similar types of slip joints should be used in high-rise buildings where interior paritions or other interior construction attaches to the exterior window wall mullion to allow for movement caused by the wind. |
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Term
| in commericial construction |
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Definition
| the structural frame of the building may be protected with fire-resistant construction rated from one to three hours. |
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Definition
| enclosed vertical area for pipes or ductwork that runs from one floor to another |
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Definition
| unit or device that radiates heat from water to the surrounding air, usually through closely spaced fins. usually placed agains a wall or under a window |
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Definition
| device placed in a duct that is designed to automatically close when subjected to a certain increase in temperature or with the detection of smoke. |
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Definition
| series of two or more risers between one floor or landing and the next |
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Definition
| heating venting and air conditioning |
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Definition
| horizontal structural member over an opening that carries the weight of teh wall above it |
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Definition
| space between a suspended ceiling and the main structure above |
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Definition
| change in elevation having two or more risers. IBC, a stairway is a change in elevation of one or more risers. |
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Term
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Definition
| portion of egress achieving a change in elevation by means of a single riser. |
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