Thermal Energy Storage and Air-to-Water Heat Exchanger in Ironbug

Hi Ladybug and Ironbug community,

I hope you are pretty well.

I have a PTHP HVAC system for a simple building. I also need to have water thermal storage attached to the PTHP. The idea is that when the PTHP is off, the space heating should be provided via the charged thermal storage. I used an air-to-water heat exchanger. Since the PTHP is like a house appliance, and there is no air duct, piping with a proper branch and a heat exchanger is required.

I have the following error when I run the simulation:


There are some problems in the logic of items attaching most probably. The simulation file is in attached.

I really appreciate it if you could kindly help me to reach out what the problem is and how I can address that.

Thank you very much for your time and assistance.

Sincerely,
Behnam
PTHP_with_TES_edit1.gh (58.6 KB)

Hi @behnammmohseni do you have a sample system working in E+ or OpenStudio model file? If yes, I can help you to recreate it with Ironbug.

Typically, if you have multiple heating systems for a thermalzone, you can use ZoneEquipmentGroup to group two zone equipments.
You can use either baseboard heating system or unitHeater to connect your hot water loop.

1 Like

Hi @MingboPeng

The main challenge is for the configuration of the PTHP that is working with air and integration that is challenging to a water plant loop, even by a heat exchanger. I checked through different documentation whether they use PTHP with other systems and I was not able to find a clue. Also, I could not find an example on the Internet whether such a system exists (PTHP+water storage tank) and an example that air-to-water HEX is used by E+ specifically.

https://www.nrel.gov/docs/fy23osti/83819.pdf (figure 76 to 89: there is no junction for PTHP)

I did the simulation with a water heater heat pump and baseboard and connected the surplus heat to a water storage tank. The simulation is working and I did the sanity check.