Heritage envelope refurbishment to manage OTTV, RTTV and preservation: The case of Sirinthorn building of Rajavithi Hospital, Bangkok

Abstract

This paper aims to reflect the refurbishment concept for a heritage building envelope for energy conservation, in particular decreasing the thermal transfer by material application. The Sirinthorn building, a heritage hospital in Bangkok is discussed as a case study which focuses on two main issues -thermal transfer by concepts that are consistent with the hospital building renovation rules, and the improvement of the conservation architecture. Factors influencing the framework include building location and environment, local regulations, an existing interior function, the materials selection concept, building shape and its identity, and conservation guidelines related to an area. The methodology is implemented by investigating the Overall Thermal Transfer Value (OTTV) and Roof Thermal Transfer Value (RTTV) from the existing envelope, in addition to 'trial and error in the selection of parameters for the heat insulation properties of industrial materials. The research output offers an optional model for the envelope refurbishment for the Sirinthorn renovation project where the effect from surrounding is discussed. The envelope is refurbished cooperatively between annexing interior insulation and restoring heritage external surfaces. Its result not only reduces the OTTV and RTTV of the case study below that of the Thai energy code, but also conserves the heritage character of the building. The outcome demonstrates the option for the use of opaque and transparent materials with properties both to save energy, internal outcome to patient zone and provide architectural conservation.