building science-heat exchange analysis of residential building

Heat Exchange Analysis Of G+3 Residential Building

Presented by

Aswin Baby

Itihas Dhareppagol

Shyam Anandjiwala

Swosti Sunder Sen

Vineeth M S

INDIAN INSTITUTE OF TECHNOLOGY DELHI

INTRODUCTION

Heat exchange mechanisms in a building:

• Conduction• Convection• Radiation

Case study:Heat exchange analysis of a G+3 residential building situated in New Delhi with aspect ratio>1

Aim: To develop a computer program in excel spread sheet to obtain the 24 hourly internal temperature for a naturally conditioned building with variable ventilation condition and comparing the results with the results obtained by computer software.

Data collection

Temperature Data obtained from: INDIAN SOCIETY OF HEATING, REFRIGERATING AND AIR CONDITIONING ENGINEERS (ISHRAE)

Radiation data from the journal: “Estimation of hourly solar radiation on horizontal and inclined surfaces in western Himalayas” by Shyam S Chandal and Rajeev K Agarwal-Scientific research journal smart grid and renewable energy-2011

Data collection (contd.)

Hourly variation of number of air exchange: assumed arbitrarily

Data collection (contd.)

Latitude :N (New Delhi)

Building Selection:

Wall Details

Cosi = Cosϒ Cosβ

Incident Radiation on walls

I = Ib cosi

Ventilation heat transfer coefficient ( Cv )values

Cv=NV/3

volume of roomV=8.7x6x3m3

∑UjAj+Cv calculations

∑AY+Cv calculations

RHS matrix calculations∑UjAjαjImj/hoj +∑AjImjθmj + Cv (i)Tfo(i) + ∑µjUjAj[Toa(i-φj)-Tmo] + ∑µjUjAjαjIfj(i-φj)/hoj +∑AjIfj(i)θj

∑UjAj + Cmv

Coefficient of Tfi for ith hour = Cvi/24

25x25 Matrix

This matrix will give the hourly temperature fluctuations along with ΔTm

Inverse of the matrix

Calculation of ΔTm and 24 hourly variation Tfi

[A] X [T]=[B]

[A]=25X25 matrix

[T]=25x1 matrix containing variables ΔTm & Tfi(i), where i=1,2,3,....n

[B]= 25x1 matrix containing RHS values

[T]= [A]-1X [B]

Thus we can obtain the fluctuating component of internal temperature

for every hour and from that total internal temperature is found out. The

above matrix calculation is for 3rd floor. Similarly we can do for all other

floors.

INTERNAL TEMPERATURE FOR THE BUILDING

GRAPHICAL REPRESENTATION OF HOURLY VARIATION OF INTERNAL TEMPERATURE FOR EVRY MONTH FOR 3RD FLOOR

SOFTWARE ANALYSIS FOR INTERNAL TEMPERATURE AND THERMAL LOADS

3D IMAGE OF BUILDING IN EQUEST

Heating and cooling loads by EQuest & Excel

Graphical plot for hourly variation of internal temperature from EXCEL

Graphical plot for hourly variation of heating/cooling load from EQUEST

Graphical plot for hourly variation of internal temperature in the month of January by Autodesk Ecotect & Excel

Graphical plot for hourly variation of internal temperature in the month of June by Autodesk Ecotect & Excel

THANK

YOU