Potengera chiphunzitso cha counter flow, mpweya wozizira umalowa mkati mwa ozizira kuchokera pansi kupita pamwamba, ma pellets otentha
kumazizira kuchokera pamwamba mpaka pansi, m'kupita kwa nthawi, ma pellets amagunda pansi pozizira, mpweya wozizira umazizira.
iwo pansi pang'onopang'ono, motere amachepetsa pellet yosweka, ngati mpweya wozizira umapitanso kuzizira kuchokera pamwamba,
zomwe zimafanana ndi ma pellets, ndiye ma pellets otentha amakumana ndi mpweya wozizira mwadzidzidzi, ndiye kuti ma pellets amasweka mosavuta,
makamaka pellets pamwamba. Mwanjira iyi imatha kuziziritsa mokwanira komanso mofanana, mlingo wosweka wa pellet ndi wocheperako kuposa 0.2%.