The relationship between inside and outside ambient temperatures in Christchurch, New Zealand.

Abstract

The objective of this study was to examine and identify relationships between hourly recorded meteorological temperature and ambient temperature, measured from within the home-sleeping environment of young infants' homes in Christchurch, New Zealand. From 1991 to 1994, home polysomnography recordings were conducted for up to 6 weeks on 32 infants aged between 2 and 24 weeks. One of the recorded signals was ambient room temperature. In total, 15735 hourly recordings of this temperature were available for analysis. The New Zealand Meteorological Service supplied hourly recordings of climatic temperature, collected over this time, from an exposed site that was considered to be representative of weather conditions for Christchurch. Temperature seasonality, hourly climatic temperature recordings and the interaction of these variables were found to be significantly related to the indoor ambient temperature recordings (all had P < 0.001). Fluctuations in hourly recorded indoor temperature appeared to lag outdoor temperature fluctuations by approximately 2 h; hence, a strong autocorrelation was identified in the regression residuals. The most parsimonious autoregression model accounted for 97% of the variability in the hourly indoor temperature measurements (r2 = 0.97). In Christchurch houses, which typically have poor thermal insulation properties, yet have no central heating capabilities, a very strong association between indoor and outdoor temperatures was clearly demonstrated.