CONTAM-TRNSYS coupling: radon simulation HRV and passive stack zero airflows in TRNSYS

[Rodrigo Mora]

Hello,

I created a CONTAM model of a house to test radon ingress. I control the heat-recovery ventilator (HRV) operation in CONTAM based on indoor radon levels. The control works fine when I ran CONTAM alone with the WTH file. The HRV successfully modulates the airflows based on radon levels.

I made the coupling in TRNSYS, which seems to work fine. including the air leakages. However, the HRV flows are always zero.. I checked all the coupling between Type 56, Type 667, and Type 98 and they look fine. 

I also created a radon source at a crawl space with a vent pipe open to the roof. However, the radon vent pipe also a=shows zero airflow. 

I am attaching the corresponding CONTAM and TRNSYS files for reference. I have tripled-checked the models and connections, and  they seem to be right. 

Thanks,

-Rodrigo   

[Dols, William Stuart (Fed)]

Rodrigo,

It seems the coupling is working fine.

This is easily verified by replacing the signal from your algorithm with a simple constant of 1.

 

As done in the cottage example, you should also connect the HRV flows of Type667 to the same terminal, i.e., 28, so they receive a positive value from CONTAM.

 

 

I’m guessing there is an issue with your control algorithm.
It always results in a value of 0 being sent to the HRV terminals for the coupled simulation and 0.3 or 0.6 for the CONTAM-only simulation (I only looked at January).

I did not evaluate your HRV algorithm, but the Radon concentrations are much different between the coupled and CONTAM-only simulations.
Concentrations are on the order of 200 to over 1000 Bq/m3 for the coupled simulation and 30 to 150 in the CONTAM-only simulation.

I had to run the simulation with a different weather file and regenerate the proforma, but I don’t think this should make too much difference in identifying the issue.

 

Flows from Terminal 1 were not always zero in simulations that I ran.

- Stuart

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