Dear Jiang Zhu, Please make sure that you are using the latest version of Trnsys17. There was a known bug with Type108 in version 16. Best regards, Matt Duffy Thermal Energy Systems Specialists Sent from my mobile wireless device. Please excuse any typos. On Apr 4, 2011, at 7:59 AM, Jay Zhu <zhujiang1124@gmail.com> wrote: > you ! > > > Jiang Zhu