Exposed Versus Concealed Services

In many buildings, the designer has a choice between exposing the mechanical and electrical services and concealing them above a suspended ceiling. Exposed services are the rule in warehouses and industrial buildings. In other types of buildings, exposed pipes and ducts can have an attractive, sculptural complexity. They are easy to reach for maintenance and revision. They make sense in many large, open buildings (athletic arenas, exhibition halls), as well as in certain other kinds of...

Design Criteria For The Selection Of Heating And Cooling Systems For Small Buildings

Decide first if the building needs a Some systems are capable of heating only, such as heating system only, or both heating Hydronic heating (pages 206-207) and cooling Solar heating (pages 208,216-217) Electric convectors and heaters (pages 211-212) Radiant panel heating (page 213) Wall furnace and direct-vent space heaters (page 214) Heating stoves (page 215) Some systems are capable of both heating and cooling the building, such as Forced air (pages 203-205) Heat pump (pages 158,204-205)...

Electrical And Communications Wiring For Small Buildings

Electrical, telephone, and cable television services reach the building via either overhead or underground wires, depending on the practices of the local utilities. Overhead wires at the street may be converted to an underground service to the building by running the service wires down the face of the pole to the required depth and then laterally to the building. An electric meter is mounted at eye level in an accessible location on the outside surface of the building. Wires from an overhead...

Vertical Load Resisting Elements

Wall and slab systems are composed of loadbearing walls spanned by horizontal slabs. The placement of walls in this system is restricted by their role as structural elements, as they must be located to support the loads from slabs and walls above. Due to the significant presence of the walls in the plan of the building, the use of a wall and slab system generally implies a close correspondence between the structural module and the planning of building functions. Furthermore, economic...

Escalators

Escalators are useful in situations where large numbers of people wish to circulate among a small number of floors on a more or less continual basis. An escalator cannot be counted as a means of egress. The structural and mechanical necessities of an escalator are contained in the integral box that lies beneath the moving stairway. Structural support is required only at the two ends of the unit, Some basic dimensional information on escalators is tabulated to the right.

Building Shape

In large multistory buildings, daylighting is most often provided through windows in exterior walls. Daylighting such as this is termed sidelighting, and its effectiveness is limited by the depth to which it can penetrate horizontally into the building interior. For example, in a typical office building daylighting can provide full illumination to task areas no farther than 12 to 15 ft (3.5 to 4.5 m) from exterior wall openings and can provide partial illumination to areas no farther than 24 to...

Column And Beam System Layouts

Columns are located on the lines of the beams above. Although column spacings may vary within the limits of the spanning capacity of the beams, for reasons of economy, columns are typically restricted to some regular gridded arrangement. Various combinations of beams and slabs are possible. Beams can span in one direction only, with slabs spanning perpendicular to them. With this arrangement, column spacing in one direction is equal to the span of the beams in the other direction, it is equal...

Exhaust Fans

Exhaust fans draw air constantly from toilet rooms, locker rooms, bathrooms, janitor closets, storage rooms, corridors, and kitchens and deliver it to the outdoors to keep the air fresh in these spaces. Exhaust fans are also used to evacuate air from laboratory fume hoods and many industrial processes.The fans are usually housed in small mushroom ventilators on the roof and are connected to the spaces they serve by ducts that run through the vertical shafts in the cores of the building. It is...

Rigid Frames

Rigid frames depend on extra stiff connections in the structural framework to resist the effects of lateral forces. The rigid joints required in this system are most easily constructed in steel, though at added cost in comparison to other systems, or in sitecast concrete where they are formed as a natural part of concrete's internal reinforcing. Rigid joints may also occasionally be constructed in precast concrete, though with greater difficulty. The absence of solid panels or diagonal bracing...

Distribution within the Structural Floor

Electrical and communications wiring may be embedded in the floor slab in conventional conduits. For greater flexibility in buildings where patterns of use are likely to change over time, systems of cellular steel decking over steel framing, or cellular raceways cast into a topping over concrete slabs, may be selected. These provide a treelike structure The trunk is a wiring trench that runs from the electrical closet to the outside wall of the building, and the branches are the hollow cells...

Central Systems Versus Local Systems

In a central system, heat is supplied to a building or extracted from it by large equipment situated in one or several large mechanical spaces. Air or water is heated or cooled in these spaces and distributed to the inhabited areas of the building by ductwork or piping to maintain comfortable temperatures. In a local system, independent, self-contained pieces of heating and cooling equipment are situated throughout the building, one or more in each room. Central systems are generally quieter...

Grouped Horizontal Distribution

Sometimes the major runs of ductwork, piping, and wiring can be grouped in the ceiling area above the central corridor of each floor of a building, leaving the ceilings of the surrounding rooms essentially clean.' This works especially well in hotels, dormitories, and apartment buildings that rely on above-ceiling all-water or electric equipment in the area adjacent to the corridor for heating, cooling, and ventilating. A low corridor ceiling is readily accepted in exchange for high,...

Designing Spaces For Mechanical And Electrical Services For Small Buildings

Small buildings are defined for purposes of this section as those that use residential-scale mechanical and electrical systems. This category includes small educational, commercial, retail, industrial, and institutional buildings as well as houses, rowhouses, and small apartment buildings. Heating and cooling loads in small buildings are usually dominated by heat gains and losses through the skin of the building. In many small buildings, mechanical fresh air ventilation is not an issue because...

Water Supply

Water from a municipal main reaches the building via an underground service pipe and a water meter. In warm climates, the meter may be outside the building, but in cold climates, it must be installed in a heated space, usually the basement or the mechanical equipment room. In many areas a tiny electronic readout, connected by wires to the inside water meter, is mounted on the outside of the building so that the meter reader does not need to enter the building. From the water meter, domestic...

Boiler Room And Chimney

The boiler room produces hot water or, less commonly, steam, to heat the building and to heat domestic water. Sometimes steam is also used to power absorption chilling equipment. A boiler room for a large building normally contains at least two boilers so that one may be in service even if the other is being cleaned or repaired. All boilers are connected to a single chimney. The boiler room may be placed anywhere in a building common locations are a basement, a mechanical room on grade, a...

Shear Walls

In tall buildings, shear walls are most commonly constructed of reinforced concrete, 12 to 18 in. (300 to 500 mm) or more in thickness. They may also be constructed of masonry, wood, or in very tall buildings, even steel. In comparison to other systems, shear walls are extremely stiff, making them a good choice wherever a relatively compact arrangement of stabilizing elements is desired. They are also relatively heavy, and must be mostly solid, with only limited openings through the wall. To...

Designing The Ceilingfloor Plenum Space

An above-ceiling location is ordinarily best for ductwork, which is often too large and bulky to fit above or within the structural floor, The wiring and ductwork must share the above-ceiling plenum space with lighting fixtures and sprinkler piping.This requires careful planning. Generally the lowest stratum, about 8 in. (200 mm) thick, is reserved for the sprinkler piping and lighting fixtures. Lighting fixture selection plays an important role in determining the thickness of this stratum,...

Daylighting Systems

This section will help you lay out the components of a daylighting system and estimate the size of daylight openings to provide the required levels of interior illumination for a project. Different tasks require different levels of illumination.The nature of a task, the need for accuracy and efficiency, and the visual acuity of the occupants are all contributing factors. For example, navigating the lobby of a commercial office building requires minimal attention to detail and is not a task with...

Fan Rooms And Outdoor Air Louvers

In an all-air system, an air handling unit in a fan room circulates air through a filter and thermostatically controlled hot water and chilled water coils to condition it. The conditioned air is ducted to the occupied spaces of the building. A return fan draws air from the occupied spaces into return grilles and back to the fan room through return ducts. Just before it passes through the heating and cooling coils again, a portion of the air is diverted by a damper and exhausted through a louver...

Checklist Of Core Components

The following is an alphabetical listing of components that are often incorporated into the cores of a building. For more information on any component, follow the accompanying page reference. Drinking fountains and water coolers (page 176) Dumbwaiters and vertical conveyors Elevator lobbies Freight elevators and freight rooms Passenger elevators Service elevators and service lobbies Escalators (page 184) Fan rooms (page 165) Fire hose and fire extinguishers cabinets (page 180) Mail chutes Mail...

Planning The Internal Arrangement Of The Cores

The ratio of the total floor area of the core or cores of a building to the floor area served varies widely from one building to the next. The average total area of the cores in 40- to 70-story New York City office buildings, including the stairways, toilets, elevators, and elevator lobbies, is approximately 27 of the open area of each floor served by the core. This ratio runs as high as 38 in some older buildings, but ranges around 20 to 24 in office towers of recent design. At the other...

Index Of Occupancies

You may use the following index of uses to determine the Occupancy Group classification for your project. If the specific use for your project is not listed, choose the most similar use based on comparisons of number and density of occupants, nature of the activity, and any associated fire- or life-safety risks. Once you have determined the building code Occupancy Group classifications for your project, you can use this information throughout the other sections of this book. If you are unsure...

Large Buildings

In large buildings energy consumption is most often dominated by internally generated heat loads, rather than by exterior climate conditions or characteristics of the building skin. The removal of heat generated by occupants, lighting, and equipment is quite often the most significant factor in the overall energy performance of a large building. In conditions such as these, daylighting can contribute significantly to energy savings. Natural daylight illumination is free.' Wherever daylighting...

Lateral Load Resisting Elements

Rigid frame action is possible in column and slab systems, although its effectiveness depends on the depth of the slab, particularly in the areas close to the columns.Where large lateral forces are expected with systems with shallow slabs, a deepening of the slab or the addition of structural beams between columns may be required to achieve sufficient lateral resistance. Shear walls or braced frames may also be used to develop lateral resistance in column and slab systems. These elements may be...

Laying Out Banks of Elevators

Elevators serving the same zone of the building should be arranged in a single bank so that waiting persons can keep all the doors in sight at one time. A bank of three in a row is the largest that is desirable four in a row is acceptable. Banks of elevators serving different zones of the building may open on opposite walls of the same elevator lobby or onto separate lobbies. The minimum width of an elevator lobby serving a single bank of elevators is 8 ft (2.45 m) and for a lobby with banks of...

Locating The Cores In The Building

A centrally located core leaves the daylit perimeter area of the building open for use. It also works efficiently with a scheme that distributes services horizontally from one set of shafts, because it minimizes duct and pipe sizes. The central location can be undesirable, however, because it interrupts the open space of the floor. A core at one edge of the building does not have this problem, but it may not be able to incorporate exit stairways that are separated widely enough (see page 245),...

Mail Facilities

Vertical gravity chutes for mail deposit are often provided in multistory buildings. The chute occupies an area of about 5 X 15 in. (125 X 375 mm) in plan and terminates in a receiving box in the base of the building. Vertical mail conveyors are sometimes provided for delivery of mail in a large multistory office building. The mailroom at the base of the conveyor should be adjacent to the loading dock and can be sized at about o of 1 of the area it serves. The walls around the conveyor shaft...

Masonry And Wood Construction

Masonry can form the exterior (and sometimes interior) loadbearing walls for either Wood Light Frame construction or Heavy Timber construction, systems named Ordinary construction and Mill construction, respectively. Both of these systems have higher fire-resistance ratings than all-wood construction and are permitted for use in larger and taller buildings. For more information on the fire resistance of these systems and the building types for which their use is permitted, see pages 312-313....

Outside Stairways And Fire Escapes

Outside stairways may be used as exits. An outside stairway must be constructed with solid treads (as distinct from the open metal gratings used for treads of outside fire escapes). It must be built to the same fire-resistive requirements as an interior stair, including separation from the interior of the building by walls and openings with fire-resistance ratings as specified for interior stairs. Outside stairways 254 must be protected against the accumulation of standing water, and must be...

Packaged Central Heating And Cooling Equipment

Packaged central heating and cooling equipment comes in two different configurations Single-packaged heating and cooling equipment combines the functions of a boiler room and chimney, a chilled water plant, and a fan room into a compact, rectangular, weatherproof unit that is specified, purchased, and installed as a single piece of equipment.The supply and return ducts from the building are connected through the roof or the wall of the building to the fan inside the packaged unit....

Ratings For Wood Light Frame Joists

Wood light frame floors with nominal 1-in. (19-mm) subflooring and finish flooring can have a 1-hour fire-resistance rating when the underside of the framing is finished with -in. (16-mm) Type X gypsum board or its equivalent. 16 (406 mm) 14 (356 mm) 117 8 (295 mm) 91 2 (241 mm) 21'-5 (6.5 m) 19'-4 (5.9 m) 15'-10 (4.8 m) 13'-4 (4.1 m) 23'-2 (7.1 m) 20'-11 (6.4 m) 17'-1 (5.2 m) 14'-5 (4.4 m) 24'-8 (7.5 m) 22'-3 (6.8 m) 18'-2 (5.5 m) 15'-4 (4.7 m) 27'-1 (8.3 m) 24'-6 (7.5 m) 20'-0 (6.1 m) 16'-10...

Rib Layout For Waffle Slab Construction

Standard 19-in (483-mm) domes are used with ribs that are 5 in. (127 mm) wide to create a 24-in. (610-mm) module. Domes of 30 in. (762 mm) are used with 6-in. (152-mm) ribs to create a 36-in. (914-mm) module. Standard domes are also available for 4- and 5-ft (1.2- and 1.5-m) modules, and other square or rectangular sizes can be specially ordered. Solid heads must be created over all columns by omitting domes in the vicinity of each column and pouring the slab flush with the bottom of the ribs....

Sizing the Components

The heat pumps may be located above a dropped ceiling over the bathroom and dressing areas in hotel rooms, or below windows. A typical under-window heat pump unit is approximately 30 in. (760 mm) high, 12 in. (305 mm) deep, and 60 in. (1525 mm) long. An above-ceiling unit has approximately the same dimensions, with the 12-in. (305-mm) dimension vertical. For the dimensions of the other components of the system, see the chart on pages 190-191.

Small Buildings

Small building energy consumption tends to be driven primarily by heating and cooling loads associated with thermal exchange through the building's exterior skin.Thus, in cold climates energy consumption is dominated by the need to replace heat lost through the walls and roof during the cold months. In warmer regions energy consumption is driven by the removal of heat gained through the exterior envelope during the warm months. Daylighting design can contribute to the reduction of energy...

Sprinkler Systems In Small Buildings

In most small buildings, sprinkler protection, when it is required, can be provided at a maximum rate of one sprinkler head per 144 sq ft (13.4 m2) of floor area. The average coverage per sprinkler head will be somewhat less than this because of the problems of fitting sprinkler layouts to rooms of varying sizes and shapes. The horizontal piping to the sprinklers is small in diameter and must run below the roof insulation in cold climates, either above a suspended ceiling or just on top of the...

Standpipes

A standpipe is a large-diameter steel water pipe extending vertically through a building, with fire hose connections at every floor. There are two types of standpipes A wet standpipe is continually filled with water and is fitted with hoses for emergency use by building occupants. A dry standpipe contains no water and is reserved for use by firefighters. In case of fire, the firefighters supply water to the dry standpipe by connecting pumper trucks to a Y-shaped Siamese connection on the front...

Variations

In direct gain passive solar heating, sunlight enters south-facing windows and warms the interior directly. Roof overhangs or louvers are configured to block out high summer sun. Internal mass (masonry, concrete, large containers of water, or small containers of phase-change salts) must be provided, Concrete floor direct gain passive solar heating Concrete floor direct gain passive solar heating attached sunspace passive solar heating attached sunspace passive solar heating preferably in direct...

Waste Compactor

A waste compactor is necessary in most large buildings. It may be coupled with a container system to facilitate the trucking of the compacted rubbish. The compactor is often served by a vertical refuse chute from the upper floors of the building. The chute must be placed in a fire-rated enclosure and must be provided with an automatic sprinkler head above the top opening. Some codes also require the provision of a 2hour enclosed chute room outside the chute opening at each floor. Inside...

Waste Piping And Sewage Disposal

Sewage flows from each fixture through a trap into waste pipes that drain by gravity. To assure that the traps do not siphon dry and to maintain constant atmospheric pressure in the waste piping, a vent pipe is attached to the waste system near each trap. The vent pipes rise upward through the building until they penetrate the roof, where they are left open to the air. The vent pipes may be gathered together into a single pipe in the attic of the building to minimize the number of roof...

Where Do I Go From Here

Once you have determined the building code Occupancy Group classifications for your project, you can use this information throughout the other sections of this book. If you are unsure of where to go next, see page xi, How to Use This Book, for suggestions on how proceed. Boarding houses Bowling alleys Children's custodial homes Children's custodial homes, not more C than 10 ambulatory persons living in a dwelling unit as a single housekeeping unit Churches, places of worship A-2 Community halls...

Building Design Development

As a design progresses and building configuration continues to develop, the impact of daylighting should be investigated in more detail and with more attention to specific local conditions. For example, a building not oriented on the cardinal points of the compass may interact with early morning and late afternoon sun in ways that require more detailed investigation. Local topography and climatic conditions may affect access to daylight at various times of the day or year. Adjacent structures...

Configuring Stabilizing Elements

The arrangement of shear walls, diagonal braces, or rigid joints in a structure is crucial to their effectiveness in resisting lateral forces acting on the building. As illustrated in the adjacent schematic floor plans, these elements may be placed within the interior of the building or at the perimeter, and they may be combined in a variety of ways. However, they must be arranged so as to resist lateral forces acting from all directions. This is usually accomplished by aligning one set of...

Zoning A Building For Heating And Cooling

Before attempting to select a heating and cooling system, rough out a zoning scheme for the building, establishing separately controlled zones so that thermal comfort can be achieved throughout a building despite conditions that differ between one space and another. Sometimes a zone should be no larger than a single room (a classroom, a hotel room). Sometimes a number of spaces with similar thermal requirements can be grouped into a larger zone (a group of offices that are occupied during the...

Total Shaft Area

Elevator Shaft Cooling

The total open area of all the mechanical and electrical shafts in a tall office building is normally equal to about 4 of the area served on each floor, and can be estimated at about half this amount for a low-rise building. This should be divided into at least two separate shafts to relieve the congestion that would otherwise occur where the vertical and horizontal distribution networks connect. It is especially effective to provide separate shafts for supply and return ducts because it is...