Retrofitting Building Roof for Energy Efficiency

Author(s): Bandana Jha (1) and B. Bhattacharjee (2)
Paper category: Proceedings
Book title: Proceedings of the 71st RILEM Annual Week & ICACMS 2017,Chennai,India, 3rd -8th September 2017
Editor(s): Manu Santhanam
Ravindra Gettu
Radhakrishna G. Pillai
Sunitha K. Nayar
ISBN: 978-2-35158-196-4
ISBN: 978-2-35158-190-2 (Set)
e-ISBN: 978-2-35158-191-9:
Publisher: Published by RILEM Publications S.A.R.L.
Publication year: 2017
Pages: 734-743
Total Pages: 10
Language : English

Abstract: A major source of heat ingress in existing-buildings is through the roofs. A bulk of cooling-
load in existing-buildings can be reduced by using energy-efficient roof-retrofitting material.

The available methods for calculating heat ingress in large-scale existing structures are
lengthy/cumbersome and manually impractical. The popular energy simulation software is
black-box type requiring inflexible/voluminous data-entries and does not optimize/select the
most energy-efficient roof retrofitting material out of available options. This paper proposes
roof-retrofitting scheme for energy efficiency through an Excel spread-sheet application. The
CIBSE admittance method is used for determination of thermal load of buildings. The
developed model is used to find the most energy-efficient solution for roof-retrofitting of a 5-
Star hotel in Delhi with minimum heat ingress, initial cost and maximum NPV. Cooling load
has been primarily considered. To confirm the validity of proposed model, energy performance
of existing roof and selected roof retrofitting materials has been evaluated using eQuest, an
established software. Results obtained confirm that the ratio of annual plant-load of existing
and optimized roof solution obtained through eQuest and proposed model are similar.
Developed model can help users select the right energy efficient roof retrofitting material,
improve thermal comfort and reduce cooling-load in existing buildings.

Online publication : 2017
Publication type : full_text
Public price (Euros) : 0.00