A 5-m-wide 3-m-high wall is constructed of one layer of common brick (k= 0.72 W/mK) of thickness 20 cm. The inner surface of the wall is maintained at 25°C while the outer surface is exposed to outdoors at 10°C with a combined convection and radiation heat transfer coefficient of 17 W/m2K. An insulation is to be added to the outside part of the wall to decrease the heat loss by 85%. Determine the thickness of insulation and the outer surface temperature if the wall is insulated with polyurethane foam (k= 0.025 W/mK)

A 5-m-wide 3-m-high wall is constructed of one layer of common brick (k= 0.72 W/mK) of thickness 20 cm. The inner surface of the wall is maintained at 25°C while the outer surface is exposed to outdoors at 10°C with a combined convection and radiation heat transfer coefficient of 17 W/m2K. An insulation is to be added to the outside part of the wall to decrease the heat loss by 85%. Determine the thickness of insulation and the outer surface temperature if the wall is insulated with polyurethane foam (k= 0.025 W/mK)

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 17P

See similar textbooks

Similar questions

Solve for what is being required. Room dimensions are: LxWxH = 8.50 m, 5.0 m, 3m. Originally, the room had linoleum flooring with an absorption coefficient of 0.03. Two opposite walls were cladded with unglazed bricks with an absorption coefficient of 0.02, the one having the entrance gypsum door (2.1 m X 0.80 m) with 0.05 abs.co.; the other two were just bare concrete with sliding glass window openings of 1.80m x 1.20 m each; the bare concrete with an abs.co. Of 0.31 and the window glass with 0.18, the ceiling, too , had bare concrete as its finish at 500 Hz. The client would like to renovate the space into an acoustical studio room and would like to change the ceiling and the flooring. The ceiling will have a vinyl faced fiberglass panel with an abs.co. of 0.71, and the floor will have mineral fiber tiles with an abs.co. Of 0.66, all at 500 Hz.
A warehouse measures 40 feet by 50 feet and has 20-foot-high walls. Thewarehouse was built on a concrete slab and has 6 inches of insulation inthe wood frame walls and 91⁄2 inches in the ceiling. There are no windowsin the building, and the door is made just like the walls. What is the heat loadfor this warehouse in an area where there is a 75°F design temperaturedifference?
Calculate the thickness of the masonry wall having thermalconductivity of 0.75 W/mK if the heat transfer is to be 80% of theheat transfer through a composite structural wall having athermal conductivity of 0.25 W/mK and a thickness of 100mm.Assume that both walls are subjected to same surfacetemperature.
Assume a pressure of 100 kPa absolute at ground level. What is the pressure (in kPa)at the top of a 3-m-high wall on the outside where the temperature is -20°C and on the inside of a house where the temperature is -22°C? (This difference results in infiltration even if no wind is present.)
A furnace wall is composed of three layers, 25cm firebrick (k=1.65W/m·K), followed by 20 cm of kaolin insulating brick(k=0.078W/m·K), and finally 15 cm of masonry brick(k=1.25W/m·K). The temperature of the inner wall surface is 935°C and outside surface is at 35 °C. Assume that surface area is 1m². (1)What is the energy transfer rate q(W)? (2) What are the temperatures at the two contacting surfaces?
Answer ONLY items 5-8. Room dimensions are: LxWxH = 8.50 m, 5.0 m, 3m. Originally, the room had linoleum flooring with an absorption coefficient of 0.03. Two opposite walls were cladded with unglazed bricks with an absorption coefficient of 0.02, the one having the entrance gypsum door (2.1 m X 0.80 m) with 0.05 abs.co.; the other two were just bare concrete with sliding glass window openings of 1.80m x 1.20 m each; the bare concrete with an abs.co. Of 0.31 and the window glass with 0.18, the ceiling, too , had bare concrete as its finish at 500 Hz. The client would like to renovate the space into an acoustical studio room and would like to change the ceiling and the flooring. The ceiling will have a vinyl faced fiberglass panel with an abs.co. of 0.71, and the floor will have mineral fiber tiles with an abs.co. Of 0.66, all at 500 Hz.
This damper is in the chimney flue of an oil burner. Through how manydegrees is it turned from its closed position?
Do a quick calculation of the thermal conductance (U value) across a cavity wall consisting of:1. Outer skin 220mm brickwork (North facing, exposed aspect) 2. 20mmcavity 3. Inner skin of 10mm plasterboard Compare this with the worked example of an insulated brick veneer wall in the worked example. Show your working.
A partition of total area 20 m2 consists of a brick wall plastered on both sides to a total thickness of 300 mm and contains a door of area 4 m2. The brickwork gives a mean sound reduction of 60 dB and the door 20 dB. Calculate the sound reduction of the complete partition.
A room in a single-story building has three 2.5 x 4 ft double-hung wood windows of average fit that are not weather-stripped. The wind is 23 mph and normal to the wall with negligible pressurization of the room. Find the infiltration rate, assuming that the entire crack is admit ting air.
Improving the insulation of the building lead to decreasing the conduction losses. Select one: True False
A cantilever retaining wall is embedded 6 m below excavation level and retains 7 m of soil. An impervious layer exists 6 m below the bottom of the wall. The water level is at the ground surface on both sides of the wall and the soil deposit is uniform and deep. Draw the water pressure diagram against the wall on both sides of the wall, assuming that the water pressure is hydrostatic. Then draw a flow net and develop the water pressure diagram on both sides of the wall. Compare and comment.