Energy efficiency in chinese apartment buildings: Parametric analysis with the DOE-2.1A computer program

Using an uninsulated Beijing apartment house of standard design as a base case, the DOE-2.1A energy analysis program is used to study the cost-effectiveness of more energy-efficient designs. Two measures have attractive simple payback times; reduced infiltration (1–2 yr payback) and insulation of the north wall (6 yr). The cost of conserved coal for the insulation measure is less than half the international price of coal. This insulation adds only 0.6% to the first cost of the building, yet, combined with more attention to infiltration, it reduces annual heat load from 230 to 130 MJ/m2. Furthermore, the first cost of these two measures may be offset by savings from downsizing the heating plant. In Shanghai, reduced infiltration and insulation are justified not on the basis of saving fuel, but because they make dwellings more comfortable.