Ma te tino korero, kaore he paerewa tino rite mo te tatauranga i waenga i te kaha whakamahana me te waahi o tewhakamatao hau wai, no te mea kei runga i te taiao e whakamahia ai te whakamatao hau. I etahi atu kupu, me iti ake te kaha whakamahana, a he rereke nga ruma noa mai i te ruma noho. Waihoki, hei tauira, ko te ruuma kei te uru ki te uru ki nga waahi wera me whakanui ake te kaha whakamahana.

I tenei wa, ko te kaha whakamahana nominal owhakamatao hau waii runga i te maakete he tino koretake me te paerewa. Ko te tino korero, me whakaatu te kaha whakamahana o te whakamahana hau wai ki te W (watts), ka whakamahia nga hoiho i te maakete ki te whakaahua i te kaha whakamahana o tetahiwhakamatao hau wai. Ko te hononga hurihanga i waenga i nga mea e rua ko: ko te kaha whakamahana o te 1 hp he tata ki te 2000 kcal, me whakareatia ki te 1.162 ka huri ki nga Watts wae o te ao. I tenei ara, ko te kaha whakamahana o te 1 hp me 2000 kcal × 1.162=2324W. Ko te W (watt) i konei ko te kaha whakamahana, me te kaha whakamahana o te 1.5 hp kia 2000 kcal × 1.5 × 1.162 = 2486W.

I raro i nga ahuatanga noa, ko te kaha whakamahana e hiahiatia ana mo ia mita tapawha mo tetahi ruma whanau noa ko 115-145W, me te kaha whakamahana e hiahiatia ana mo ia mita tapawha mo te ruma noho me te rūma kai he 145-175W.

Hei tauira, he 15 mita tapawha te rahi o tetahi ruma noho whanau. Mena ko te kaha whakamahana mo ia mita tapawha he 160W, ko te kaha whakamahana o te whakamahana hau wai ko: 160W×15=2400W.

I roto i tenei ara, te XK-20S taiepa-whakaekeawhakamatao hau waime te kaha whakamahana 2500W ka taea te hoko kia rite ki te kaha whakamahana 2400W e hiahiatia ana.

Ko te mea e kiia nei ko te tauwehenga kaha o te kaha, e mohiotia ana ko te whakarea o te mahi, ko te ōwehenga o te kaha whakamatao ingoa o tewhakamatao hau waiki tona kai mana. I te nuinga o te wa, he tata ki te 3 neke atu ranei i te 3 te tauwehenga kaha o te hau whakamatao wai, a no te kai whakamatao hau wai whakaora.

Hei tauira, te kaha whakamahana o te kotahiwhakamatao hau waihe 2000W me te 640W te kaha o te mana whakamahana o tetahi atu whakamatao hau wai ko te 2500W me te 970W te kaha whakamahana o te hau. Ko nga owehenga kaha o nga hau e rua: ko te tauwehenga kaha o te whakamatao hau wai tuatahi: 2000W/640W=3.125, me te ōwehenga kaha o te whakamatao hau wai tuarua: 2500W/970W=2.58. I tenei ara, na roto i te whakataurite o te kaha o te kaha o te hau o te hau wai e rua, ka kitea ko te tuatahi o te rangi he whakamahana hau wai whakaora. Ko te maha o te whakamatao hau wai e pa ana ki te mana whakauru o te whakamatao hau wai, e hono autaki ana ki te waahi e whakamahia ana, a, e hono tika ana ki te waahi whakamahi ko te kaha whakamahana. I roto i toku whenua, ko te kaha whakamahana o te whakamatao hau wai kotahi te tikanga mo te 2300W. He rereke etahi o te rahinga.

Ko te hoahoa whakamatao hau wai ka hangaia kia rite ki nga mita putorino o te waahi, ara, kotahi mita pūtoru te kaha whakamahana o te 50W, a ka taea e nga kaihoko te tatau i te waahi e tika ana mo te whakamahana hau wai kia rite ki te teitei o o raatau ake whare.

Hei tauira: he iri hoiho kotahi, ko te kaha whakamahana he 2300W

Ko tona rōrahi e hāngai ana ko te 2300/50=46 mita pūtoru

Mena he 3 mita te teitei o te ruma, ko te horahanga e tika ana ko te 46/3=15.3 mita tapawha.

I te wa e whiriwhiri ana, me whai whakaaro ano te whakatakotoranga o te whare me te mea kei runga i te papa o runga. Me tika te whakanui ake i te kaha whakamahana ki runga i te papa o runga. E taunaki ana kia whiriwhiria te 2500W.