1) Conditions: Outside winter time -10C and 60% RH. What is the moisture content of the outside air? Provide your answer to within 0.0004 kg wv/kg dry air of the correct answer. 2) Conditions: Outside winter time -10C and 60% RH. What is the enthalpy of the outside air? Provide your answer to within 2 kJ/kg dry air of the correct answer. 3) "Use the outside air from the first 2 questions. Now bring this outside air inside for ventilation of a house, and heat it to 24C (without adding moisture). What is the new RH (relative humidity) of this air? Provide your answer to within 3% of the correct answer." 4) What is the moisture content of dry air and water vapour at 24C and 35% RH? Provide your answer to within 0.0004 kg wv/kg dry air of the correct answer. 5) "Now using the outside air you have warmed up in question 3. How much moisture do you need to add to this air now, so that at 24C it will be at 35% RH? Provide your answer to within 0.0004 kg wv/kg dry air of the correct answer." 6) What is the enthalpy of dry air and water vapour at 24C and 35% RH? Provide your answer to within 2 kJ/kg dry air of the correct answer. 7) "What is the energy (enthalpy) change in the air going from outside conditions (-10C , 60% RH) to the final inside conditions (24C , 35% RH)? i.e. How much energy has to be added to the dry air/water vapour system to make it comfortable for indoors? Provide your answer to within 2 kJ/kg dry air of the correct answer." 8) Going back to the outside air you have warmed up to 24C in question 3. What is the enthalpy of this air? Provide your answer to within 2 kJ/kg dry air of the correct answer. 9) "How much SENSIBLE heat is added in Question #7, taking outdoor air and changing it to the desired indoor conditions? Provide your answer to within 2 kJ/kg dry air of the correct answer." 10) "How much LATENT heat is added in Question #7, taking outdoor air and changing it to the desired indoor conditions? Provide your answer to within 2 kJ/kg dry air of the correct answer." 11) "Given that the outside air is brought in as per Question #3 to 24C, without adding any moisture. Now to add the moisture you will allow water to evaporate naturally (adiabatic process=constant enthalpy) to bring the RH up to 35%? What will be the temperature of this cooled air in the room? Provide your answer to within 1.5C of the correct answer." 12) "For question #11, how many degrees will the temperature drop below 24C due to the evaporation of liquid water into the air? Provide your answer to within 1.5C of the correct answer." 13) What is the dew point temperature of this dry air/water vapour mixture (24C and 35% rh)? Provide your answer to within 1.5C of the correct answer. 14) "Some of this air (24C and 35% rh) now comes in contact with a cool exterior window, whose inside window pane is at 5C, and the dry air + water vapour mixture coming into contact with this inside pane cools to the temperature of the pane. What will be the moisture content of the air that gets cooled by this window? Provide your answer to within 0.0004 kg wv/kg dry air of the correct answer." 15) "For the situation in Question #14, how much water vapour condenses out of each kg of dry air that is cooled to the window temperature of 5C? Provide your answer to within 0.0004 kg wv/kg dry air of the correct answer."
1) Conditions: Outside winter time -10C and 60% RH. What is the moisture content of the outside air? Provide your answer to within 0.0004 kg wv/kg dry air of the correct answer.
2) Conditions: Outside winter time -10C and 60% RH. What is the enthalpy of the outside air? Provide your answer to within 2 kJ/kg dry air of the correct answer.
3) "Use the outside air from the first 2 questions. Now bring this outside air inside for ventilation of a house, and heat it to 24C (without adding moisture). What is the new RH (relative humidity) of this air? Provide your answer to within 3% of the correct answer."
4) What is the moisture content of dry air and water vapour at 24C and 35% RH? Provide your answer to within 0.0004 kg wv/kg dry air of the correct answer.
5) "Now using the outside air you have warmed up in question 3. How much moisture do you need to add to this air now, so that at 24C it will be at 35% RH? Provide your answer to within 0.0004 kg wv/kg dry air of the correct answer."
6) What is the enthalpy of dry air and water vapour at 24C and 35% RH? Provide your answer to within 2 kJ/kg dry air of the correct answer.
7) "What is the energy (enthalpy) change in the air going from outside conditions (-10C , 60% RH) to the final inside conditions (24C , 35% RH)? i.e. How much energy has to be added to the dry air/water vapour system to make it comfortable for indoors? Provide your answer to within 2 kJ/kg dry air of the correct answer."
8) Going back to the outside air you have warmed up to 24C in question 3. What is the enthalpy of this air? Provide your answer to within 2 kJ/kg dry air of the correct answer.
9) "How much SENSIBLE heat is added in Question #7, taking outdoor air and changing it to the desired indoor conditions? Provide your answer to within 2 kJ/kg dry air of the correct answer."
10) "How much LATENT heat is added in Question #7, taking outdoor air and changing it to the desired indoor conditions? Provide your answer to within 2 kJ/kg dry air of the correct answer."
11) "Given that the outside air is brought in as per Question #3 to 24C, without adding any moisture. Now to add the moisture you will allow water to evaporate naturally (adiabatic process=constant enthalpy) to bring the RH up to 35%? What will be the temperature of this cooled air in the room? Provide your answer to within 1.5C of the correct answer."
12) "For question #11, how many degrees will the temperature drop below 24C due to the evaporation of liquid water into the air? Provide your answer to within 1.5C of the correct answer."
13) What is the dew point temperature of this dry air/water vapour mixture (24C and 35% rh)? Provide your answer to within 1.5C of the correct answer.
14) "Some of this air (24C and 35% rh) now comes in contact with a cool exterior window, whose inside window pane is at 5C, and the dry air + water vapour mixture coming into contact with this inside pane cools to the temperature of the pane. What will be the moisture content of the air that gets cooled by this window? Provide your answer to within 0.0004 kg wv/kg dry air of the correct answer."
15) "For the situation in Question #14, how much water vapour condenses out of each kg of dry air that is cooled to the window temperature of 5C? Provide your answer to within 0.0004 kg wv/kg dry air of the correct answer."
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