Closed CarlosOchoaIERC closed 3 weeks ago
@CarlosOchoaIERC Can you attach the IDF file to reproduce please?
Solar Colector 10 m2 - PV 20 m2-Customized.zip Hi, I'm attaching the file as zip since GitHub says it does not support .idf
@CarlosOchoaIERC so this file runs fine, and has no WaterHeater:Mixed that has an autosized volume. It has 4 Waterheater:Mixed objects, which one am I supposed to set to autosized volume?
Trial and error: setting Solar Loop Water Heater to autosize is sufficient to produce the NaNs.
@CarlosOchoaIERC so this file runs fine, and has no WaterHeater:Mixed that has an autosized volume. It has 4 Waterheater:Mixed objects, which one am I supposed to set to autosized volume?
Trial and error: setting Solar Loop Water Heater to autosize is sufficient to produce the NaNs.
Hi Julien, they were all supposed to be initially in autosize. Hope this helps.
The issue is specific to the Solar Loop Water Heater. It's really a very specific combination of factors that lead to the issue:
As a result the collector area is found to be 0.0, there are zero warnings/errors reported.
The tank volume becomes zero, so the mass of the fluid is also 0, and in CalcTankTemp, you end up with a NaN due to a divide by zero.
This tank has "Ambient Temperature Indicator" set to "Zone", and that NaN propagates to the zone internal gains, and you end up with a DualSetPointWithDeadBand error due to that.
PR that fixes it:
Thanks a lot for the thorough analysis!
Issue overview
Similar to #10464 , there is a fatal error when forward translating an old file and asking to autosize the WaterHeater:Mixed
Severe DualSetPointWithDeadBand: Unanticipated combination of heating and cooling loads - report to EnergyPlus Development Team ~~~ occurs in Zone=BLOCK1:ZONE1 During Warmup, Environment=DUBLIN ANN HTG 99.6% CONDNS DB, at Simulation time=02/21 00:00 - 00:10 ~~~ LoadToHeatingSetPoint=NAN, LoadToCoolingSetPoint=NAN ~~~ Zone Heating Set-point=20.00 ~~~ Zone Cooling Set-point=20.00 ~~~ Zone TempDepZnLd=2367.13 ~~~ Zone TempIndZnLd=NAN ~~~ Zone ThermostatSetPoint=20.00
The issue disappears if the water tank is provided with a fixed volume. All the schedules cover the relevant DesignDays.
Details
Some additional details for this issue (if relevant):