The heating, ventilation, and air conditioning (HVAC) system is arguably the most complex system installed in a building and is responsible for a substantial component of the total building energy use. Maintaining optimal temperature and air circulation are the basis of a comfortable indoor environment[1]. This role is played by HVAC (Heating, ventilation and air conditioning) systems. The heat load calculations along with the duct design for a HVAC system installed in a multistorey residential building is calculated and analyzed to maintain a desired temperature based on outer environmental temperature. The duct design is analyzed which create an impact on system performance. The layout of a multistorey residential building is made by using Autodesk REVIT software. A complete air conditioning system was designed along with ducts and VAV system to control the indoor environment conditions like temperature, relative humidity, air movement, etc. Based on the obtained Heat Load Calculations CFM & T.R values were found for each spaces and ducting design was done for all the spaces by considering the quantity of CFM to be supplied. A suitable air handling unit (AHU) is selected based on the CFM value for multi storey residential building. With this the capacity of equipment was estimated and selected for the installation.

A proper condition assessment of reinforced concrete structure after a fire event involves field and la-boratory work to determine the extent of fire in order to design an appropriate and cost effective repair scheme. The present paper presents a case study where an attempt has been made to carry out a condition assessment of a fire damaged building in a systematic manner. The approach adopted broadly consisted of questioning of on-site per-sonnel, a detailed visual survey, on-site non-destructive / partially-destructive tests, collection of in-situ samples from site along with some laboratory based investigations on samples collected from site. Differential Thermal Analysis (DTA), X-Ray Diffraction (XRD) Analysis and Scanning Electron Microscopy (SEM) Imaging were con-ducted for microstructural characterization and analysis of concrete to correlate, corroborate and validate the results obtained through on-site assessment. Since the building was an old structure, carbonation depth in structural mem-bers was also evaluated. Finally, based on the visual inspections indicating the condition of surface and structural elements such as spalling, exposure and condition of reinforcement, cracks, honeycombing etc. along with Non-Destructive Test / Laboratory test results, the repair methodology of structural members are presented.