渗透是家庭能量平衡的一个重要因素，但在所有使用的计算中，渗透流量的预测是最不准确的。造成这种不准确的原因有很多，其中大部分是由于房屋结构的变化以及许多建筑构件的紧密配合。通过几种实验手段可以发现特定结构的渗透特性，其中一种是使用风扇增压装置（FPD）或所谓的“鼓风机门”。FPD用于许多应用，但最常见的是节能改造项目。使用FPD的流量和压差测量值，可以根据劳伦斯伯克利实验室和其他地方开发的计算程序估算自然渗透率。建议改进措施的程度取决于改进前和改进后泄漏测试显示的空气泄漏减少量。 有几个不同的FPD制造商，它们在结构中使用不同的设计和材料，因此它们的准确性、再现性以及操作员对结果的影响存在很大的不确定性。该测试使用四个不同的FPD和三个不同的操作员，根据适当的ASTM测试标准（ASTM，1987）在四个不同的房屋上进行循环测试。使用ASTM E691（ASTM，1979）对结果进行分析，以进行实验室间试验计划。结果表明，当将压力-流量曲线外推至4 Pa时，风扇校准或操作员技术中的细微误差被大大夸大。在4 Pa时，结果的总范围高达+/-40%，操作员差异（重复之间）通常为+/-5%或更小。在大多数情况下，FPD本身的可变性远远大于使用不同运算符引入的可变性。增压试验的差异略大于减压试验。 计算中使用的室内压力越高，测试结果就越一致。50 Pa时的重复性差异通常优于+/-5%，而操作员差异通常优于+/-2%。增压和降压试验的结合确实略微改善了总体可变性。由于设备部件和操作人员技术中的随机误差占可测量量的比例较大，因此，在较紧的房屋中，误差的百分比通常较大。较紧的外壳要求在风机上放置限流板，以获取低压读数，风机标定表明，使用它们的三个FPD中的两个在开放流量和限制流量情况下的标定结果存在显著差异。一般来说，FPD性能可以根据其风扇校准曲线进行解释。安装FPD时，FPD周围的空气泄漏估计在最坏的情况下会产生2%的误差，而在最紧的装置上，误差小于1%。

Infiltration is a significant factor in a home's energy balance, yet prediction of infiltration flow rates is the least accurate of all the calculations that are used. There are several reasons for this inaccuracy, most of which stem from variations in the construction of houses and in the tightness of fit of the many building components. Infiltration characteristics of a particular structure can be found by several experimental means, one of which is to use a fan pressurization device (FPD), or the so-called "blower door". FPDs are used in many applications, but most commonly in energy conservation retrofit programs. Using the flow rate and pressure differential measurements from the FPD, a natural infiltration rate can be estimated from calculation procedures developed by Lawrence Berkeley Laboratories and elsewhere. The extent to which retrofit measures are recommended is based on the amount of reduction in air leakage indicated by pre- and post-retrofit leak tests. There are several different manufacturers of FPDs and they use different designs and materials in their construction, so there is much uncertainty about their accuracy, reproducibility, and the impact of the operator on the results. This test utilized four different FPDs and three different operators to conduct round robin tests on four different houses according to the appropriate ASTM test standard (ASTM, 1987). The results were analyzed using ASTM E691 (ASTM, 1979) for conducting an interlaboratory test program. The results indicate that subtle errors in fan calibration or operator technique are greatly exaggerated when extrapolating the pressure versus flow curve out to 4 Pa. The total range of results were as much as +/- 40% at 4 Pa, with operator differences (between replications) normally +/- 5% or less. In most cases, the variability of the FPDs themselves was far greater than the variability introduced by using different operators. Variances were somewhat larger for pressurization tests than for depressurization tests. The higher the house pressure used in the computations, the more uniform the test results became. Repeatability variances at 50 Pa were usually better than +/- 5% while the operator differences were usually better than +/- 2%. Combining pressurization and depressurization tests did improve the overall variability slightly. Errors were generally larger on a percentage basis for the tighter houses, since the random errors in equipment components and operator technique constituted a larger fraction of the measurable quantity. The tighter houses required a flow restriction plate to be placed on the fans for the low pressure readings, and fan calibrations indicated a significant difference in calibration results between the open flow and restricted flow cases for two of the three FPDs that used them. In general, the FPD performance could be explained on the basis of their fan calibration curves. The leakage of air around the FPD while it is installed was estimated to produce a 2% error in the worst case, and less than 1% error for the tightest unit.