旋转式热交换器的固有特性是将少量的废气流体输送到供给流体中，这在一些空对空热交换器应用中造成了问题。如果供应流体（例如，医院供应空气）需要高纯度，或者排气流体中含有细菌或有毒气体（例如，工业或化学过程中的排气），则由遗留物引起的实际污染水平变得很重要。送风污染可能由几种传输机制的组合造成。当排气从排气流旋转到供应流时，排气可能被困在基质中。这种传递被称为“传递”，与基质空隙的体积和基质速度成正比。它基本上与两个管道之间的压差无关，可以通过以最低实际速度运行基质和使用吹扫装置将其保持在最小值。 另一个污染效应是排气通过径向和周向密封件泄漏。·其大小取决于密封件的类型、条件和调整，以及两股气流之间的压差。可通过使用将排气管保持在比供气管更低的静压的风扇布置来防止排气泄漏到供气管中。引文:研讨会，ASHRAE交易，第81卷，第2部分，马萨诸塞州波士顿

The inherent characteristic of rotary heat exchangers to carry small amounts of the exhaust fluid into the supply fluid poses a problem in some air-to-air heat exchanger applications. In situations where either a high degree of purity is required for the supply fluid (e.g., hospital supply air) or where the exhaust fluid is bacteria laden or contains noxious gases (e.g., exhaust from industrial or chemical processes) actual levels of contamination caused by the carry-over become important.Supply air contamination can result from a combination of several transfer mechanisms. The exhaust air can be trapped within the matrix as it rotates from the exhaust stream to the supply stream. This transfer is termed "carry-over11 and is directly proportional to the volume of the matrix voids and the matrix speed. It is essentially independent of the pressure differential between the two ducts and can be maintained at a minimum by operating the matrix at the lowest practical speed and by the use of a purge device.Another contaminating effect is the leakage of exhaust air across the radial and circumferential seals. · Its magnitude depends on the type, the condition and the adjustment of the seals as well as the pressure differential between the two streams. Leakage of exhaust air into the supply air may be prevented by using a fan arrangement that maintains the exhaust duct at a lower static pressure than the supply duct.