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9 Cards in this Set
- Front
- Back
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Which of the following statements about duct leakage losses is true? 1) Air leakage varies from 40% to 45% 2) The effects of air leakage in supply air ducts are the same as those in return ducts 3) Losses from bare supply air ducts within the conditioned space have a substantial impact on loss calculations 4) Losses due to air leakage from furred supply air ducts within the conditioned space can only be evaluated on the basis of judgement 5) Leakage inspection can only be done after the duct is covered in insulation |
Losses due to air leakage from furred supply air ducts within the conditioned space can only be evaluated on the basis of judgement |
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Functions of terminal air distribution devices are accomplished: 1) By aspiration, entrainment, induction, and diffusion 2) Only by diffusion and aspiration 3) Only by entrainment and aspiration 4) Only by entrainment and diffusion 5) Only by diffusion |
By aspiration, entrainment, induction, and diffusion |
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Medium and high pressure duct systems require less space than low pressure duct systems, but this feature is partly offset by: 1) Higher operating cost and higher initial cost of air handling apparatus 2) All of the above 3) Costly special control devices and costly noise suppressing devices 4) More costly fabrication and installation of ductwork 5) Higher first cost for special equipment is required to reduce the air velocity before distribution to the air space |
All of the above |
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Fibreglass ducts are used: 1) In high pressure systems 2) In some low pressure systems 3) Where high strength is required 4) To handle air with high moisture levels or oil and grease 5) Where its heavy weight is not a problem |
In some low pressure systems |
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Supply air duct leakage loss calculations include: 1) 5% leakage loss when the supply air duct is outside the conditioned space 2) 20% leakage loss when the supply air duct is outside the conditioned space 3) 10% leakage loss when some of the supply air duct is outside the conditioned space and some inside 4) 10% leakage loss when the supply air duct is outside the conditioned space 5) Losses from bare supply air ducts within the conditioned space |
10% leakage loss when the supply air duct is outside the conditioned space |
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Return air duct leakage calculations include: 1) 5% seepage if the return air duct is outside the conditioned space 2) 3% seepage if the return air duct is outside the conditioned space 3) 3% seepage if the return air duct is both inside and outside the conditioned space 4) 10% leakage if the return air duct is inside the conditioned space 5) 3% leakage if the return air duct is inside the conditioned space |
3% seepage if the return air duct is outside the conditioned space |
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Classifications of air conditioning ducts include: 1) Low pressure and medium pressure 2) Heating and cooling 3) Low pressure, medium pressure, and high pressure 4) Absorption and compression 5) Medium pressure and high pressure |
Low pressure, medium pressure, and high pressure |
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A ventilation system leading from a fume hood in a chemistry lab would have which duct material used for its ductwork? 1) Black steel sheet metal 2) Aluminium sheet metal 3) Fiberglas 4) Galvanised steel sheet metal 5) Cement asbestos |
Cement asbestos |
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Seepage in return air ducts returned within the conditioned space may have what kind of effect? 1) It will add to the amount of air needed to supply the cooled space 2) It will ruin the duct's insulation 3) It will increase the load on the air system in terms of pressure 4) It will create a loss of cooling effect 5) It will increase the load on the air system in terms of volumes of air |
It will increase the load on the air system in terms of volumes of air |
