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GSHP with Radiant, no flow in radiant loop

I'm modeling a GSHP loop, with secondary loops for radiant heating and cooling. I'm using the water-to-water heat pump component to transfer heat from the GSHP loop to the secondary loops. Right now there is no flow in the radiant loops and I can't figure out why.

GSHP loop is set up like this, with the water-to-water heat pump on the demand side. image description

Radiant hot water loop is set up like this image description

I am really stuck on this. If anyone has any insights please let me know. Thank you!

avril14's avatar
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avril14
asked 2019-01-24 16:46:12 -0500
__AmirRoth__'s avatar
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__AmirRoth__
updated 2019-01-27 09:46:52 -0500
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The heat exchanger component can sometimes not be autosized correctly. It assumes a really high Delta T between the loops and it ends up being a really small flow. If you could upload your .osm file it would be easier to tell what's going on.

I modelled a similar scenario and I had the same issue.

Luis Lara's avatar Luis Lara (2019-01-25 07:44:07 -0500) edit
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I tried hard sizing the heat pump but that didn't have any effect. You can take a look at the file here if you have any other ideas. link text Thank you so much!

avril14's avatar avril14 (2019-01-25 11:46:35 -0500) edit
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I managed to figure this out eventually. For anyone else having the same issue, I made a few changes but I think what ultimately fixed it was: - Re-ordering the components in the Thermal Zones tab so that the Radiant elements were first in the list. - Adjusting the internal source constructions to make sure the radiant loops were between the right layers. - If using the constant flow radiant, changing the temperature schedules to be controlled by Outdoor Air Temp instead of the zone air temp.

avril14's avatar
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avril14
answered 2019-02-01 11:09:58 -0500
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I have the same problem, I'm trying to create a radiant floor powered by a heat pump (Heat Pump Water Heater) in summer and by a chiller in winter. As in your case I have no flow, you could better explain these two points: - Adjusting the internal source constructions to make sure the radiant loops were between the right layers. - If using the constant flow radiant, changing the temperature schedules to be controlled by Outdoor Air Temp Instead of the zone air temp. Thank you so much

GioBot's avatar GioBot (2019-10-16 03:34:53 -0500) edit
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