代写BRE2031 – Environmental Science Tutorial IAQ and Ventilation代做Java程序

Subject: BRE2031 – Environmental Science

Tutorial IAQ and Ventilation

1. A room is cooled in summer by an air conditioning system that provides an air flow rate of 5m3/s to remove heat gains (sensible) of 50kW.  Room air temperature is maintained at 23oC. Derive the formula for calculating the supply air temperature and find its value. (the heat capacity of air can be considered as constant:  1005J / (kg . K) ; air density: 1.2929kg / m3 at 273K).  (reference answer: about 14.9oC)

2. A room has heat gain (sensible) of 10kW and a supply air temperature of 10oC.   Find  the supply air rate required to keep the room air temperature at 20oC. (reference answer: 0.798m3/s)

3. A four-story commercial building is to be mechanically ventilated.  Air-handling plant is to be sited on the roof. Each floor has dimensions 20m×10m×3m and is to have 6 air changes per hour (ACH). Of the air supply,  10% is  allowed to exfiltrate naturally and the remainder (90%) is extracted to roof level. The supply and extract air ducts run vertically within a concrete service shaft and the limiting air velocity is  10m/s. Estimate the dimensions required for the service shaft. Square ducts are to be used and there is to be at least 150mm between the duct and any other surface.  (reference answer: about 1680mmx 930mm)