National Conference Emerging trends of Energy Conservation in

4. Conclusion
Table4. Correlation between Envelope parameters and Annual Space Cooling and
Heating Energy- Building D- All Climates.
The U- value of opaque wall and U- value of the window glass are building envelope
parameters which show poor correlation with annual space cooling and heating energy.
Therefore, Building Energy Codes which specify limiting criteria based on these parameters
of the building envelope can be reevaluated based on objective of achieving energy
efficiency. The envelope parameters such as shading coefficient of window glass and wall
solar transmittance have good correlation with annual space cooling and heating energy and
also shading coefficient has significantly high magnitude of influence. Hence, the orientation
and shading characteristics of the building envelope are crucial to the energy performance of
the building envelope and require emphasis in envelope criteria in building energy codes.
References
window
parametric
runs Constant:
Uw= 1.74,
=0.6
wall
parametric
runs Constant:
SC= 0.26, Uwin=
4.99
Building D (WWR= 0.41) high-rise
Dependent
Slope Intercept
Coefficient
of
Correlation
variable Climate (m) (c) (R)
Composite 9.68 19.4 0.97
SC Hot- Dry 11.4 23.1 0.98
Warm Humid 12 25.1 0.99
Composite 0.72 22.34 0.40
U-window Hot- Dry 0.79 26.6 0.39
Warm Humid 0.78 29 0.37
Composite 0.82 20.29 0.95
Uw* Hot- Dry 0.9 24 0.99
Warm Humid 0.96 26.7 0.97
Composite 0.37 20.32 0.77
U-wall Hot- Dry 0.36 24.11 0.67
Warm Humid 0.42 26.77 0.76
1. Devgan, S., Jain, A. K. and Bhattacharjee, B. (2010). “Predetermined overall
thermal transfer value coefficients for Composite, Hot- Dry and Warm- Humid
climates”. Energy and Buildings, Vol. 42, pages 1841-1861.
2. BEE. (2007). “Energy Conservation Building Code”. Bureau of Energy
Efficiency, Ministry of Power, Government of India. www.bee-india.nic.in.
3. Devgan, S. (2009). “Development of OTTV based approach for three tropical
climates as an alternative to prescriptive approach in building energy codes”.
Unpublished PhD thesis, Indian Institute of Technology, Delhi, India.