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.

Some tips for success on using the forum:

  • Follow the Forum Rules posted in Forum Administration.
  • There are categories for different types of topics and questions. Post your topic or question into the proper category.
  • Before posting a topic or question search the existing topics  (and the TRNSYS Users listserv archive or Post archive) to see if a similar topic or question has already been answered.
  • Use a descriptive topic name. Don’t use attention getting subjects, they don’t get attention and only annoy people.
  • State the version of TRNSYS and which add-ons your are using.
  • Include enough specific details for your topic of question to be answered. Just posting “Why am I getting an error?” without describing the specific error and what you are trying to do when you get the error will not receive a response that fixes your issue.
  • Remember when people help you, they are doing you a favor. Be patient, help people out by posting good descriptions of what you need help with, and be polite even if a response does not solve your issue.
  • Moderators may edit your post for clarity or move your topic to a more appropriate category.

DavidBradley
@davidbradley
Admin
Member
Joined: Jan 20, 2023
Last seen: Jul 11, 2025
Topics: 30 / Replies: 235
Reply
Answer to: Transient energy storage in tanks of phase change materials

@charles-maragna I would recommend trying to contact the authors of the paper. You might also look at Prof Katherine D'Avignon's work specifically at ...

1 year ago
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RE: Issue with linking Matlab file with TRNSYS

@salwa When we compile Type155, we have to link it to four *.lib files. The *.lib file that is referenced in your screen capture (libmx.dll) is one o...

1 year ago
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Answer to: Issue with linking Matlab file with TRNSYS

@salwa It is a bit unclear to me when the error is occurring. Do you get this error as soon as you launch the coupled simulation? If so then I would...

2 years ago
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RE: my tip for fixing Internal error in solar radiation distribution (sumsitot) in TRNSYS

@dromar123 thank you for the tip. Would you be willing to share what data you found to be erroneous and how you modified it to get that particular gla...

2 years ago
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Answer to: Adaptive Comfort Model

@m-m yes. The Trnsys18 building model has a PMV/PPD calculation built in. There is also a component in the TESS Libraries v18 that provides a little...

2 years ago
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Answer to: How can I fix the error of 'wall must be adjacent to a different zone' when my wall is?

@eman_mag I have not encountered that error; would you mind posting the *.idf (and *.b18 file if one is being generated) so that I can have a look? ...

2 years ago
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RE: TRNSYS, Type29

@academictester and @petaxa @petaxa @academictester is correct; I did apparently fix this issue with a v18 release. The v17 copy that I was using ...

2 years ago
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Answer to: Is there any tool in TRNSYS to perform a kind of inverse technique to estimate unknown parameters of a component based on experimental data?

@ken The way that I usually do this is to use TRNOpt (part of the TESS Optimization library). Essentially you can define a cost function (in your ca...

2 years ago
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RE: Active Layer Settings

@Manaya_ Your English is excellent! Please accept my apologies for the delay in responding to your follow up. I believe that the active layer mode...

2 years ago
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Answer to: Type 45a: how to modify the friction factor?

@ken I believe that equation 4.9.2-5 applies to the collector inlet and outlet pipes whereas the other equation applies to the pipes and risers tha...

2 years ago
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RE: How to modify the set value of the maximum of a parameter of a TRNSYS proforma?

@ken It may be worth noting that sometimes the limits that are placed on proformas are there because of limitations in the code. For instance, Type45...

2 years ago
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Answer to: How to modify the set value of the maximum of a parameter of a TRNSYS proforma?

@ken, Changes that you make to the proformas are not automatically reflected in projects that use those proformas. Think of the proforma as a template...

2 years ago
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Answer to: Type 45a: how could a heat exchanger be included in the tank model?

@ken, I think that you would have to modify the source code in order to do that. Does the collector you are modeling have a load side heat exchanger? ...

2 years ago
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Answer to: Loop statement unsupported in TRNSYS 18?

@baumstrunk Damian, if the LOOP command is not functioning in v18 it is a bug and not something intentional. That said, Type22 has the concept o...

2 years ago
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Answer to: Latent gain from plants

Type56 takes latent gains in kg/h of water so as an absolute humidity gain. As a side note, there is an evapotranspiration model included in the lat...

2 years ago
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