Chiratidzo chekushanda kwesefa yemhepo chinonyanya kureva kushanda zvakanaka kwekubvisa guruva, kuramba, uye kugona kubata guruva. Kushanda zvakanaka kwekubvisa guruva kunogona kuverengerwa zvichienderana nenzira inotevera:
Kubvisa guruva zvakanaka = (G2/G1)×100%
G1: Avhareji yehuwandu hweguruva mufirita (g/h)
G2: Avhareji yeguruva rinogona kusefa (g/h)
Kushanda zvakanaka kwekubvisa guruva kunoenderanawo nehukuru hwezvimedu. Kuramba zvinoreva kudzvanywa kwakasiyana. Pachishandiswa fungidziro yekuti firita iite zvakanaka, kudzvanywa kudiki kuchava nani zvikuru. Kuramba kuri kuwedzera kuchaita kuti simba rishandiswe zvakanyanya. Kuramba kwakanyanya kuchaita kuti compressor yemhepo idengenyeke. Saka, unofanira kutsiva chinhu chefirita kana firita ichiramba kusvika kana kuti iri pedyo nekumanikidzwa kwevacuum. Pamusoro pezvo, kugona kubata guruva zvinoreva avhareji yeguruva rakaungana panzvimbo imwe neimwe. Uye unit yayo i g/m2.