HEAT AND MASS TRANSFER ENGINEERING
A proposal has been made to modify the room in building to include a 3 m high horizontal ceiling. This requires a re-design of the ventilation and air-conditioning system (see Figs. 1, 2). Your task is to propose a new layout for the supply air and return air ducting for the room, select an appropriate number of diffusers and their locations, decide appropriate flow rates for supply air (SA) and return air (RA), calculate all volume flow rates of air in every part of your system and determine the pressure drop across the fan in the AHU for your proposed design condition. There is no requirement to make use of existing ductwork.
Figure:1- Overall concept for Design
The air handling unit will be a similar design to the existing one as illustrated in Fig. 3. For this assignment you do not need to know the dimensions of the existing ductwork or specifications and dimensions of the existing air handling unit. You may decide the ductwork dimensions yourself in your design.
Fig. 4 Existing Air Handling Unit (AHU) in the plant room
Fig. 5 Scale Plan. The project applies to Laboratory 1. The air handling unit is to be located in the Plant Room. Laboratories 2 and 3 already have their own separate AHUs and are not included in the scope of this design.
The design report should include: A title page
A concise summary of your report
A plan view drawing (preferably CAD) showing the number, locations and size of ducting, diffusers and return air inlets (Based on Fig. 5). It is suggested that supply-air ductwork is drawn in blue and return-air ductwork in red.
A table reporting the return air volume flow rate, supply air flow rate, exit air flow rate and pressure drop across the fan
A table (or a drawing) showing the velocities and volume flow rates of the air in your ductwork at all locations where the velocity is different (for your proposed design condition). Calculations showing how you determined the flow rates and required pressure drop for the fan at your design condition. You must clearly state any assumptions you made. A recommended fan for the AHU and type of diffuser
A list of references