At 04:35 AM 5/26/2005, Adriana Angelotti wrote:
I'm using type 89 mode -3 to read EnergyPlus weather data (an epw file). Time step is 1h.It seems that type 89 shifts and interpolates all data (except solar radiation data), as in the exampleyou can read below. Is it correct? What does it mean? Thank you for helping.
Adriana,It's important to realize that the outputs from TRNSYS components are (and should be) the average value over the timestep, not the value at the end of the timestep. Energy+ files contain instantaneous values of ambient temperature. Looking at the Energy+ data you provided, the temperature was 4 degrees at midnight and 1.2 degrees at 1 am. Using simple linear averaging, the average temperature over the period of midnight to 1 a.m.(recorded as hour 1 by TRNSYS) is then (4+1.2)/2 or 2.6 degrees; exactly that provided by Type 89. I hope this helps.
Jeff ********************************************************************************* Thermal Energy System Specialists (TESS) Jeff Thornton 2916 Marketplace Drive Principal Suite 104 Phone: (608) 274-2577 Madison WI 53719 Fax: (608) 278-1475 USA E-mail: thornton@tess-inc.com Web Page: www.tess-inc.com "Providing software solutions for today's energy engineering projects" *********************************************************************************