The comparison of four methods for the calculation of deep-basement heat loss is presented along with measured data for three basement types. The Mitalas method was found to give results in best agreement with measured data followed by the finite element method (FEM) program, the European Standard and the ASHRAE Fundamentals method. The studied methods, with the exception of the European Standard of which the physical background was unknown, were chosen because each of them is also representative of a particular physical model of decreasing complexity in the above order.
Ventilation of the void below suspended timber floors is necessary to prevent dampness, which leads to wet and dry rot. The air flow beneath such a floor has been investigated for a range of ventilator hole positions, using a full-sized test room. The variations in heatlosses with ventilation rate have been measured, for floors with and without insulation. The use of radiation barriers in place of conventional thermal insulation was found to cut down the heat losses significantly at low ventilation rates, but was not so effective at higher rates.
In order to reduce the heat loss from buildings it is common to increase the thickness of insulation in the building envelope.The consequence of this action is more expensive buildings. Building regulations in countries with cold climate require U-values far the envelope which results in thicker and therefore often stronger constructions than needed for structural capacity. Another strategy to save energy has been to reduce the ventilation rates in buildings.
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