Welcome to the TRNSYS Users Forum.
The forum is a place where people can interact and have discussions about different topics involving the use of the TRNSYS software package. Here you can post topics for discussion or questions on using TRNSYS and get advice from other users or TRNSYS experts. This forum is not intended for detailed technical support. Users should contact their distributor’s hotline for such assistance.
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Last seen: Jun 10, 2026
@amir_i The idea of Type780 is that you pass a moisture gain rate to the building model, which in turn deals with the latent energy impacts of addin...
@amir_i What timestep are you using for your simulation? It should be on the order of 1-5 minutes. Lately I have been using 0.02 or 0.05 hours as my...
@amir_i good question! Add a humidity gain in TRNBuild and assign it to be an input. You'll then connect the evapotranspiration mass flow rate to th...
@shamsoddinghiami There are a couple of errors referenced in the screenshot and I think the one that says that an illegal input specification was fo...
@kashif10 can you also please screenshot the list of all the notices that are displayed along with the error? I am not so interested in the error or...
@shamsoddinghiami you are correct; the way that Type1302 is written only one instance can be included in a simulation. There is a method by which a ...
@hamza Sorry for the late reply. Type56 performs an energy balance on the roof surface and calculates a surface temperature. The energy balance assu...
@sw17032 It sounds like you are doing all the right things. It is hard to diagnose these problems because they are specific to the setup of each com...
@shamsoddinghiami Shams, while you are limited to only one instance of Type56 in a simulation project it is possible to define groups of thermal zo...
@sw17032 I would recommend sending the project file and supporting files to your distributor's hotline so that they can look at the project in more de...
@sw17032 There are a few things that might be worth checking. first, are the source inlet and outlet temperature exactly the same value or are they ...
@am_hassan I will preface the following by saying that I am not an expert in this subject at all! However, there are a number of cases in which TRNS...
@leomodra In addition, bear in mind that even if the value of the equation that sets the azimuth changes during the simulation the azimuth angle of...
@humbertosantos If the dll is from 2006 and if it works (or at least starts running) with Trnsys v17 then it is compiled as a 32-bit dll. Trnsys 18 ...
@mohammedzaoui The TRNSYS heat pump models read capacity and COP as a function of inlet temperatures from an external data file. Because they are p...