Energy Analysis Error when using Hydronic System

Hi, I am having some errors with a simple parametric energy model. I am basing this off of a study that I did a while ago, but now it comes up with lots of errors when I run it. Could any of the updates to the components now need more inputs or have different baselines? Mostly I am having issues when I switch to the fan coil HVAC option- see photo.
Additionally when I run for the hydronic system the heating seems too high, which could be due to the error. Any thoughts are appreciated. Thanks. (658.1 KB)

@msilver ,

I could not recreate the E+ warning on my system:

What version of OpenStudio are you using?
Versions 2.6 and 2.7 of OpenStudio have some known bugs in them that make them incompatible with particular Honeybee workflows. So we recommend that you use OpenStudio 2.5 for now if you need full Honeybee energy modeling capabilities.

Thanks Chris for quick reply!

I am using Open Studio version 2.5. The error suddenly isn’t appearing anymore for me either - but the heating values are still way higher than I would expect. This is skewing the EUI to show that the VAV system is lower than the hydronic system. Any ideas as to why? Thanks.

@msilver ,

If you are trying to approximate the behavior of chilled beams in a hospital, you should NOT be setting the recirculation on the DOAS:

Chilled beams get a lot of energy savings in hospital scenarios because the recirculation happens on the beam itself (by entraining the air of the room) rather than having to be completely recirculated through the air loop (resulting in a lot more fan power).

A VAV system should have this type of air loop recirculation because VAV diffusers can’t recirculate air locally such that they have to reciculate air all of the way back through the air loop. Trying to do this type of recirc on an air loop that is only sized for minimum ventilation (a DOAS) is can be pretty inefficient because the smaller ducts result in larger pressure rises and more times that the fan is working at max power rather than in its more efficient ranges.

Yup- that fixed it, and makes a lot of sense. Thank you!