Fix #11039: supp heat blocked by negative QToHeatSetPt#11546
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brianlball wants to merge 7 commits intodevelopfrom
Open
Fix #11039: supp heat blocked by negative QToHeatSetPt#11546brianlball wants to merge 7 commits intodevelopfrom
brianlball wants to merge 7 commits intodevelopfrom
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Unit test proves supplemental heating is blocked when QToHeatSetPt < 0 despite zone demand exceeding primary coil capacity. The check at controlUnitarySystemtoLoad (~line 8125) compares FullSensibleOutput against QToHeatSetPt — when the zone predictor underestimates heating need, QToHeatSetPt goes negative and backup never fires. Test will pass once the fix is applied.
…into issue-11039-supp-heat-blocked
Supp check used QToHeatSetPt as threshold — when negative (predictor overestimates zone temp), positive coil output always passes check, blocking supp. Two fixes: 1. Constant-fan ZoneLoad overwrite (lines 10808/10830/10856/10878): use max(QToHeatSetPt, QZnReq) to preserve original demand signal. Previously missed the DualHeatCool deadband case at line 10878. 2. Supp check zero-floor: when HeatingLoad is true but suppLoadTarget is negative, floor at 0 so supp fires when primary can't achieve neutral output. Handles SingleHeat where QZnReq==QToHeatSetPt. VSHeatPump integration test: 53.25 → 15.00 unmet heating hours (-72%).
New test: SuppHeatBlocked_ConstantFan_DualHeatCool — continuous fan, DualHeatCool deadband, QToHeatSetPt=-500, QToCoolSetPt=3000. Verifies supp fires via the zero-floor fix when primary targets negative load. Fails on unfixed code, passes with fix. Reverted line 10878 (DualHeatCool deadband) from max(QToHeatSetPt,QZnReq) back to QToHeatSetPt. The max() produced ZoneLoad=0 which triggered the small-load guard at line 10942, killing HeatingLoad. The supp check zero-floor handles this case instead.
…into issue-11039-supp-heat-blocked
brianlball
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Is there a defect file to test? I won't believe this change unless I see a defect file's result change for the better. |
mitchute
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max(QToHeatSetPt, QZnReq) produced ZoneLoad=0 in deadband, triggering the small-load guard that cleared HeatingLoad. Supp heat zero-floor at line 8207 is sufficient alone.
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Summary
QToHeatSetPtnegative. The supp check (FullSensibleOutput < QToHeatSetPt) always passes when QToHeatSetPt is negative.initLoadBasedControloverwritesZoneLoad = QToHeatSetPt, making the primary coil target the wrong (negative) load. The supp check then sees the primary "met" the target and doesn't fire.ZoneLoadatmax(QToHeatSetPt, QZnReq)in 3 constant-fan heating paths to preserve original demand signal; (2) floorsuppLoadTargetat 0 whenHeatingLoadis true, so supp fires when primary can't achieve neutral output.Test plan
SuppHeatBlocked_NegativeQToHeatSetPt— cycling fan, SingleHeat, negative QToHeatSetPt. Fails on develop, passes with fix.SuppHeatBlocked_ConstantFan_DualHeatCool— constant fan, DualHeatCool deadband, negative QToHeatSetPt. Fails on develop, passes with fix.