<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> </head> <body bgcolor="#ffffff" text="#000000"> Dear users, has anybody experiences with the humidification control of the basic zone controller? Our model setup: Our test room model is a single zone, contains a fixed infiltration flow rate and has no internal gains (using opr-file). A basic zone controller is used for cooling and dehumidification control (setpoints for dehumidification e.g.: maximum RH 30%, maximum humidification rate 1g/s). Summer weather conditions of south Germany are used. The problem: As a result, the relative humidity target within the room is always achieved due to dehumidification, although the results analysis manager output shows dehumidification loads which are significantly smaller than what would be theoretically expected (from Mollier-h-x diagram) in order to achieve the RH target. For testing, we have drastically reduced the maximum dehumidification rate to 0.1 g/s. Consequently, the RH target is sometimes not achieved and the maximum dehumidification load output is 0.25 kW (which seems correct as 1g/s should equal 2.5 kW). However, for this small dehumidification load, the RH should be much higher than what is calculated by ESP-r. In other words, the dehumidification load output does not seem to suit to the calculated RH and is significantly smaller than it would be expected from h-x diagram for achieving the resulting RH. The error seems to increase with higher room air changes (see examples below): Example 1 Conditions: Air change rate of 11.56h-1 Ambient T and RH 18.35°C and 77.5% Zone T and RH 17.76°C and 30% Resulting dehumidification load: Theoretical: 2370W ESP-r output: 360 W Difference: 86% Example 2 Conditions: Air change rate of 1.0h-1 Ambient T and RH 18.35°C and 77.5% Zone T and RH 18.0°C and 30% Resulting dehumidification load: Theoretical: 203W ESP-r output: 140W Difference: 32% Has anybody an idea about this phenomenon? We saw this problem in the newest version of ESP-r and also in an older version. Any comment is appreciated. Regards, Tobias <pre class="moz-signature" cols="72">-- Dr. Tobias Zitzmann Project Manager Dept. Thermal Systems and Buildings Fraunhofer-Institut für Solare Energiesysteme ISE Heidenhofstraße 2, 79110 Freiburg, Germany Phone: +49 (0) 7 61/ 45 88-55 82 Fax: +49 (0) 7 61/ 45 88-95 82 tobias.zitzmann(at)ise.fraunhofer.de <a class="moz-txt-link-freetext" href="http://www.ise.fraunhofer.de">http://www.ise.fraunhofer.de</a> </pre> </body> </html>