DOAS VRF cuts out at 50C outdoor DBT

Hey good folks,
Question for all of you: I’m modeling building behavior at high temperatures and notice that where outdoor DB temperatures cross 50C the system cuts out.

Does this come from a known physical limitation of the VRF system? If so, does anyone have a citation? Other HVAC templates do not behave in a similar way, it seems specific to the VRF system. Any high-level explanation would be greatly appreciated.
Thanks for your help and Happy New Year!

50C outdoor temperature. Is your building in Death Valley?

I don’t know exactly what the setting is but I know that the VRF systems have lots of controls and I wouldn’t be surprised if one of them involves the system shutting off (or at least struggling with conflicting controls) when the outdoor temperature is that high. I would imagine that you can change it by editing the OSM manually or with the OpenStudio SDK if you knew which properties of the VRF were causing the shut-off.

If you want to ask the official source about this, these HVAC templates are all added via the openstudio-standards gem. Some of the maintainers of the standards gem check the UnmetHours forum. So you might try asking the question there to see if anyone has suggestions.

Wonderful, thank you very much @chris. Not quite Death Valley…Kuwait City: At 53.5°C, Kuwaiti City Becomes Hottest Place on Earth !!!


ahhh ~50c, the temperature threshold you know you’ve crossed when you can tell ‘I should go sit in the shade’ by the fluid in your eyeballs feeling too hot!

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