winter

Living room winter temperatures are explored using data from 397 randomly selectedhouses from the Household Energy End-use Project (HEEP). HEEP has collected energyand temperature data on a statistically representative sample of New Zealand houses(Latitudes 35S46S). Initial analysis of the winter (June-August) living roomtemperatures shows that heating type, climate, and house age are important drivers ofindoor temperatures. On average, houses heated by solid fuel are the warmest, withhouses heated by portable LPG and electric heaters the coldest.

In cold and moderate climates, improvements in building shell insulation and air-tightness imply a shiftin heating loads from transmission and infiltration towards ventilation. Heat recovery from the ventilation airflow plays an increasingly important role in minimising energy needs. Such heat recovery systems rely on the input of electric power (to drive fans, heat pumps, etc.) in order to recover thermal energy. Since electricity input is relatively small compared to the amounts of thermal energy recovered, such systems are efficient from an energy viewpoint.