%0 Report
%A Marc O Abadie
%A Elizabeth U Finlayson
%A Ashok J Gadgil
%D 2002
%G eng
%T Infiltration heat recovery in building walls: Computational fluid dynamics investigations results
%1 <p>2.3</p>
%2 LBNL-51324
%X <p>Conventional calculations of heating (and cooling) loads for buildings assume that conduction heat loss (or  gain) through walls is independent of air infiltration heat loss (or gain). During passage through the  building envelope, infiltrating air substantially exchanges heat wall insulation leading to partial recovery of  heat conducted through the wall. The Infiltration Heat Recovery (IHR) factor was introduced to quantify  the heat recovery and correct the conventional calculations.  In this study, Computational Fluid Dynamics was to calculate infiltration heat recovery under a range of  idealized conditions, specifically to understand factors that influence it, and assess its significance in  building heat load calculations. This study shows for the first time the important effect of the external  boundary layers on conduction and infiltration heat loads. Results show (under the idealized conditions studied here) that (1) the interior details of the wall  encountered in the leakage path (i.e., insulated or empty walls) do not greatly influence the IHR, the overall  relative location of the cracks (i.e., inlet and outlet locations on the wall) has the largest influence on the  IHR magnitude, (2) external boundary layers on the walls substantially contribute to IHR and (3) the  relative error in heat load calculations resulting from the use of the conventional calculational method (i.e.,  ignoring IHR) is between 3% and 13% for infiltrating flows typically found in residential buildings.</p>