The impacts of high performance glazing on typical light timber framed houses in a New Zealand winter

Abstract

This paper reports on a project which uses two full-scale, three-bedroom standard houses to identify the impact of changes in building elements and materials on indoor environmental quality. The lightweight, timber framed, stand-alone houses are characteristic of New Zealand construction, and meet the requirements for the current New Zealand Building Code in terms of materials and insulation. One of the houses served as the test case for the research and incorporated high performance argon-filled Low-E double glazing. The second house acted as a control, with identical design and location but built using standard construction practice including conventional double glazing. The paper details the impact of the Low E argon filled double glazing on internal temperature during a monitoring period which ran over the New Zealand winter. It compares results for this wintertime period to the results of previous testing of the same houses over the summertime period, and also examines results in relation to the short-term laboratory-predicted impacts of material thermal performance. Findings indicated that throughout the wintertime period, both houses performed similarly. In both cases the most notable issue was the high internal temperatures reached on cold sunny days. There were minor performance differences between the standard double glazing and the Low-E glazing. The temperatures reached in the Low-E test house on cold sunny days were less extreme than in the control house, but overnight and early morning temperatures were lower with the high performance glazing. On cold overcast days there was negligible difference between the two double glazing types.