(b) (a) A lecture theatre has dimensions 25m x 25m x 8m high and has a...

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(b) (a) A lecture theatre has dimensions 25m x 25m x 8m high and has a capacity for 180 people. The ventilation air contains 400ppm of CO: and the average person when seated breaths 20 times per minute, exhaling 0.0015m3 of air per breath containing 4% of CO₂ Determine the air change required to limit the concentration to 1800ppm when the lecture theatre is full. The appropriate formula is: C₁ = [c₂ + Rx106 nV With respect to the Building Regulations Part LIA for new domestic dwellings, discuss the design concepts of trading off and "limiting values'. Give examples to illustrate how these ideas apply to U-values and the air permeability of the "as built' dwelling. (c) Table Q3(c) contains data for a wall that is constructed of several layers and with layer thicknesses and values for material resistance to vapour transmission as shown. Also included in the table are the values for temperature at the outer surface of each layer that have been previously calculated for this wall for the conditions shown below. inside air condition: outside air condition: Using a psychrometric chart and the formula given below as necessary: (i) Determine the vapour pressure distribution through the wall. (ii) Determine the distribution of the dew point temperature through the wall. (iii) Without drawing a graph, state whether interstitial condensation is likely to occur. 1 Table Q3(c) LAYER MATERIAL WIDTH, X 23456 3 4 ~J(₁-e 1 - e™ ) + C, e* 5 6 temperature=21°C, relative humidity = 50% temperature -2°C, relative humidity - 100% BLOCK INSULATION AIR PLASTER 0.02 0.15 0.10 0.112 BRICK AIR . Resistivity (GNs/kgm) 40 50 250 80 Useful formulae: moisture content, g=0.622x AIR TEMP T(K) 21 20.29 20.09 18.88 -0.82 -1.65 -2.00 where pa 101,300 Pa (b) (a) A lecture theatre has dimensions 25m x 25m x 8m high and has a capacity for 180 people. The ventilation air contains 400ppm of CO: and the average person when seated breaths 20 times per minute, exhaling 0.0015m3 of air per breath containing 4% of CO₂ Determine the air change required to limit the concentration to 1800ppm when the lecture theatre is full. The appropriate formula is: C₁ = [c₂ + Rx106 nV With respect to the Building Regulations Part LIA for new domestic dwellings, discuss the design concepts of trading off and "limiting values'. Give examples to illustrate how these ideas apply to U-values and the air permeability of the "as built' dwelling. (c) Table Q3(c) contains data for a wall that is constructed of several layers and with layer thicknesses and values for material resistance to vapour transmission as shown. Also included in the table are the values for temperature at the outer surface of each layer that have been previously calculated for this wall for the conditions shown below. inside air condition: outside air condition: Using a psychrometric chart and the formula given below as necessary: (i) Determine the vapour pressure distribution through the wall. (ii) Determine the distribution of the dew point temperature through the wall. (iii) Without drawing a graph, state whether interstitial condensation is likely to occur. 1 Table Q3(c) LAYER MATERIAL WIDTH, X 23456 3 4 ~J(₁-e 1 - e™ ) + C, e* 5 6 temperature=21°C, relative humidity = 50% temperature -2°C, relative humidity - 100% BLOCK INSULATION AIR PLASTER 0.02 0.15 0.10 0.112 BRICK AIR . Resistivity (GNs/kgm) 40 50 250 80 Useful formulae: moisture content, g=0.622x AIR TEMP T(K) 21 20.29 20.09 18.88 -0.82 -1.65 -2.00 where pa 101,300 Pa

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a The concentration of CO2 in the lecture theatre is 1800ppmThis means that there are 1800 parts of CO2 per million parts of air The ventilation air c... View the full answer