Comparative thermal performance of new and old houses

The commitment to reduce energy consumption in buildings has focused attention on improving thermal insulation by employing measures such as the use of insulated cavity walls, double glazed sealed windows and insulated lofts. The energy consumption and thermal performance of two different types of house, an old and a new detached house are compared. Attention was focused on the living areas. The rate of air in-flow as determined by tracer gas, the air velocity and temperature distribution at two levels of 0.15 and 1.2 m were measured. The results show that in the new house the temperature difference between a seated personʹs head and ankle is more than 3 °C. This difference is increased when the central heating is switched on. In both houses the gap under the entrance door is large and contributes to a high internal air velocity. Despite the inadequacy of the installed air ventilator, the energy efficiency of the new house is demonstrated.