Mhepo duct hita ichaiswa muduta rakatenderedzwa mushure mekupinda mhepo sefa, pamberi peHRV unit inlet.Yakagadzirirwa kudzivirira defrosting mode, kureva kudzivirira kugadzira kushomeka kushoma mukati memba.Iyo heater inodzorwa ne thermostat, ichichinja pasi pekunze kwekunze tembiricha chete.