Ko te AHU Ahumahi he taputapu whakahaere hau e hangaia ana i runga i nga hiahia o te kaupapa kua tohua, ka honoa ki te whakamahana, te whakamahana (te wai/te tima/te wera o te hau me etahi atu), te whakamahana/te whakamaarama (te maaka/te rehu/te wira etc), te horoi o te rangi (horoi/ filtration/electrostatic etc), whakaora pūngao, me etahi mahi e tika ana ki te hanga i te āhuarangi o roto tino pai ki te makona i te hiahia tukanga hanga hangarau o te awheawhe ahumahi.

Kua whakapau kaha a Holtop ki te hanga ahumahi hanga otinga kounga hau mo nga tekau tau mai i te hoahoa wae, hangahanga, wheketere i mua i te huihuinga me te whakamatautau, te tuku kaipuke, ki te whakaurunga o te waahi, te tono, te whakangungu me te tiaki.Ka whakaratohia e matou nga whiringa ngawari ki te whakatutuki i nga whakaritenga o to whare whakangao, mahi ranei.Kei a matou te raupapa 50B, 80C, 80B mo nga waahanga rereke rereke.