Walls exterior

Acoustical Louvers. Acoustical louvers are used in building mechanical systems when exterior walls are penetrated for fresh air intake, exhaust, or rehef air, in situations where the impact of HVAC noise is of concern in the surrounding environment. The louvers consist of a series of hoUow sheet metal blades. The bottom faces of the louver blades are perforated and the blades are filled with fibrous sound-absorbing material. Typical acoustical louvers are 20 cm (8 in.) to 30 cm (12 in.) in depth. The amount of insertion loss they provide is limited. 

Place equipment to be vented close to an exterior wall, if it must be placed indoors the vent ducts should be free of bends and no longer than 3 m (10 ft). 

Monitor exterior wall temperature with infrared optical detection system, and operating instructions for operator response if high temperature signal occurs... 

Outdoor air is generally less polluted than the system return air. However, problems with reentry of previously exhausted air occur as a result of improperly located exhaust and intake vents or periodic changes in wind conditions. Other outdoor contamination problems include contaminants from other industrial sources, power plants, motor vehicle exhaust, and dust, asphalt vapors, and solvents from construction or renovation. Also, heat gains and losses through the building envelope due to heat conduction through exterior walls, floor, and roof, and due to solar radiation and infiltration, can be attributed to effects from external sources. 

Magnesium oxychloride cements are widely used for the fabrication of floors. They find application for this purpose because of their attractive appearance, which resembles marble, and also because of their acoustic and elastic properties and their resistance to the accumulation of static charge. They have also been used for plastering walls, both interior and exterior for exterior walls the cement often includes embedded stone aggregate (Sorrell Armstrong, 1976). However, there have been problems with this latter application, since the base cement has been found to be dimensionally unstable and, in certain circumstances, to release corrosive solutions and show poor weather resistance. 

EXAMPLES FOR SPACE HEATING WALL ELEMENTS FOR EXTERIOR WALLS... 

Wall elements for exterior walls to heat a building have been investigated for several decades. The basic idea is explained in Figure 171. 

A sampling station is provided on the rear exterior wall of the facility for flow measurement and monitoring of the effluent stream. 

Figure 3 indicates a roof detail at an exterior wall. Note that the upper surfaces of joists are detailed to be sloped to minimize dust collection and that all interior joints are taped to prevent manufacturing components and product from entering joints. Exterior surfaces of insulation should receive a coating of weather-resistant paint. 

Standard Method of Test for Heat Release Rates for Upholstered Furniture Components or Composites and Mattresses Using an Oxygen Consumption Calorimeter, 1990. Ignitability of Exterior Wall Assemblies Using a Radiant Heat Energy Source, 1994. 

In this example calculation, only the exterior wall is evaluated for blast loads. 

Load calculations braced frames 12-39—12-43 columns 11-37—11-40 exterior walls 11 4—11-10 foundations 11-41—11 45, 12-43—12-46 rigid frames 12-31 — 1 2-39 roof beams 1 1-27—1 1-31 roof decking 12-6—12-71 roof girders 1 1-36 roof putins 1 2-16—1 2-26 roof slabs, in-plane 1 1-1 1 — 1 1-16 roof slabs, out-ofplane 1 1-21—1 1-26 side walls, in-plane 11-16—11-20 wall girts 12-26—12-30 wall panels 12-12-12-16... 

Consideration should be given to certain interior items. Functional or decorative objects should not be mounted on the interior surface of an exterior wall. Rapid inward movement of the wall may dislodge objects causing injury to people or damage equipment. For the same reason, file cabinets and other furnishings should not be placed closer to the interior surface of a wall than the maximum predicted deflection of the wall. 

Braced frames on exterior walls, long dimension, 25 ft (7.6 m) spacing,... 

This chapter provides an example of the evaluation and retrofit of the masonry walls of an existing reinforced concrete framed building using the principles outlined in Chapter 10. The evaluation of the roof, structural framing and foundation are not covered in this example. The explosion magnitude and front wall blast load are determined by others. The analysis of the exterior walls, and upgrade options, arc presented in this example. 

Fig. 4.13 Triangular network of d-spaced nanotubes in a bundle marked are van der Walls gap (g), and positions of H atoms on the exterior wall (a, b) and in the interior of tube (c)...

Furthermore, where the conservation of heat in a plant is important, and the walls of the building are otherwise of strong construction, a section of exterior wall may be built of light wood, or hollow tile or some other material which is relatively weak compared to the rest of the building so that in case of an explosion, these sections will give first... 

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