A multi-zone typical office floor is air-conditioned with a dual duct VAV system. Supply air enters...

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A multi-zone typical office floor is air-conditioned with a dual duct VAV system. Supply air enters each zone through VAV terminals, which regulate the portions of cold and hot air to maintain the setpoint of the zone temperature. In summer, the design condition for the air leaving the cooling coil is at 13°C and 95% saturation. One of the zones is a conference room, which is maintained at 23°C at the summer cooling mode when occupied. The space sensible and latent load of the conference room are 30kW and 4.5kW, respectively. 1-a) Determine the design airflow rate supplied to the conference room and the space relative humidity at the design condition. 1-b) On a humid day with outdoor temperature of 32°C, the conference room is partially occupied, and its sensible load is only 10kW. The airflow of the VAV system under this particular condition is illustrated in Figure Q1. It is assumed that the supply fan raises the air temperature by 1°C, and the minimum supply air to the conference room is 60% of the design airflow. Calculate the required supply air temperature and the hot and cold air flow rates supplied to the conference room. 1-c) With the reference to the part-load condition in part (b), comment on the operation of this dual duct VAV system and compare it with a terminal reheat VAV system. O.A. 0.8 m³/s 32°C 90% RH E.A. VCD Supply fan R.A.3.2 m³/s 24°C #A Cooling coil Heating coil (deactivated) T= 13°C # th Zone Conference room 23°C Figure Q1: A dual duct VAV system at a part-load condition. A multi-zone typical office floor is air-conditioned with a dual duct VAV system. Supply air enters each zone through VAV terminals, which regulate the portions of cold and hot air to maintain the setpoint of the zone temperature. In summer, the design condition for the air leaving the cooling coil is at 13°C and 95% saturation. One of the zones is a conference room, which is maintained at 23°C at the summer cooling mode when occupied. The space sensible and latent load of the conference room are 30kW and 4.5kW, respectively. 1-a) Determine the design airflow rate supplied to the conference room and the space relative humidity at the design condition. 1-b) On a humid day with outdoor temperature of 32°C, the conference room is partially occupied, and its sensible load is only 10kW. The airflow of the VAV system under this particular condition is illustrated in Figure Q1. It is assumed that the supply fan raises the air temperature by 1°C, and the minimum supply air to the conference room is 60% of the design airflow. Calculate the required supply air temperature and the hot and cold air flow rates supplied to the conference room. 1-c) With the reference to the part-load condition in part (b), comment on the operation of this dual duct VAV system and compare it with a terminal reheat VAV system. O.A. 0.8 m³/s 32°C 90% RH E.A. VCD Supply fan R.A.3.2 m³/s 24°C #A Cooling coil Heating coil (deactivated) T= 13°C # th Zone Conference room 23°C Figure Q1: A dual duct VAV system at a part-load condition.

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To address these questions we will take them step by step 1a Determine the design airflow rate supplied to the conference room and the space relative humidity at the design condition To determine the ... View the full answer