Abstract



This research examines heat loss through a prefabricated suspended timber ground floor, designed for the proposed educational facility at Cuilin House,Hamstead Park Dublin 9 for Dublin City Council. The work specifically concerns the quantitative evaluation of heat transfer through thermal bridging and thermal bypass. Four prefabricated suspended timber ground floor build-ups were developed through a detailed design investigation. The materials used in the floor and abutting wall remained a constant throughout the investigation.

Two and three dimensional predictive heat transfer modelling software was used to analyse the thermal performance of each floor build-up. U-values and Psi Values for a building envelope do not consider the effects of heat loss due to poor installation of insulation, due to poor workmanship. This research shows a significant increase in the U -value when the corrected calculation for thermal bypass was applied to the Uvalue calculation which had a role in determining the most effective placement of insulation for a suspended floor construction. This research has demonstrated that the tested form of construction with insulation above, below and between the joists reduces the affects of thermal bypass even if one layer of insulation was poorly installed.
The results in this research reveal that as the Surface U-value improves the Psi value increases indicating that it is becoming more difficult to meet current building regulation requirements for Psi values, as required U values decrease.