Dear Younness, I would not worry about switching to the detailed humidity model in Type56; the simple one is quite adequate. Make sure that the humidity multiplier is set to a value between about 5 and 15. This indicates that the zone has between 5 and 15 times the moisture capacitance of the air in the zone. If you only consider the moisture capacitance of the air (by setting the multiplier to 1) then you are discounting the fact that the furnishings and the wall materials in the zone can absorb (and desorb) moisture. I think also that you are modeling the variation in RH correctly, its just that based on your system, there isn't a very good way to dry out the space. Look carefully at the RH of the ventilation air that you are putting into the space. If its RH is high and if there are any latent gains in your space (from occupants or from cooking, for example) then the moist air in the residence has no way of drying out. Try changing the conditions of the air that you are putting into the space by means of a VENTILATION type; set the RH (arbitrarily) to 30% and make sure that the RH in the zone drops to something close to that level. Kind regards, David On 12/29/2011 10:38, youness EL FOUIH wrote: Dear TRNSYS users, -- *************************** David BRADLEY Principal Thermal Energy Systems Specialists, LLC 22 North Carroll Street - suite 370 Madison, WI 53703 USA P:+1.608.274.2577 F:+1.608.278.1475 d.bradley@tess-inc.com http://www.tess-inc.com http://www.trnsys.com |