Expected 1 element (EER) for Room Air Conditioner

[lukeduran]

We've received several of these errors. My gut tells me that this has to do with us passing multiple systems per type; however, this was not previously happening. Originally, if we sent more than one system, only one was being acknowledged. Has this changed?

Request

            "addressFull": "125 Douglas Dr, Jefferson City, MO 65109-0969",
            "addressComponents": {
                "addressLine1": "125 Douglas Dr",
                "city": "Jefferson City",
                "stateAbbreviation": "MO",
                "zipCode": "65109-0969"
            },
            "baseBuilding": {
                "buildingSummary": {
                    "yearBuilt": 1955,
                    "bedroomsCount": 3,
                    "averageCeilingHeight": 8,
                    "conditionedFloorArea": 2256
                },
                "enclosure": {
                    "airInfiltration": {
                        "rate": 1859,
                        "rateUnit": "CFM"
                    },
                    "attics": [
                        {
                            "floorAssemblyEffectiveRValue": 44,
                            "id": "attic-insulation-1"
                        }
                    ],
                    "foundations": [
                        {
                            "type": "basement unconditioned",
                            "id": "floor-and-foundation-insulation-1"
                        }
                    ],
                    "walls": [
                        {
                            "assemblyEffectiveRValue": 12,
                            "id": "wall-insulation-1"
                        }
                    ]
                },
                "systems": {
                    "hvac": {
                        "hvacHeatingSystems": [
                            {
                                "systemType": "furnace",
                                "fuel": "natural gas",
                                "heatLoadFraction": 1.0,
                                "heatEfficiency": 0.8,
                                "heatEfficiencyUnits": "AFUE",
                                "id": "heating-systems-1"
                            },
                            {
                                "systemType": "furnace",
                                "fuel": "natural gas",
                                "heatLoadFraction": 0.0,
                                "heatEfficiency": 0.67,
                                "heatEfficiencyUnits": "AFUE",
                                "id": "heating-systems-2"
                            }
                        ],
                        "hvacCoolingSystems": [
                            {
                                "systemType": "central air conditioner",
                                "coolLoadFraction": 0.9,
                                "coolEfficiency": 14.0,
                                "coolEfficiencyUnits": "SEER",
                                "id": "cooling-systems-1"
                            },
                            {
                                "systemType": "room air conditioner",
                                "coolLoadFraction": 0.1,
                                "id": "cooling-systems-2"
                            }
                        ]
                    },
                    "waterHeating": {
                        "waterHeatingSystems": []
                    }
                }
            },
            "globalControls": {
                "debug": true,
                "includeInputs": true,
                "includeBase": true,
                "includeTypical": true,
                "useFixture": false,
                "resolution": [
                    "annual",
                    "monthly"
                ],
                "timelineStartDate": "2024-04-08",
                "timelineDurationInYears": 1,
                "units": {
                    "energyStandard": "MBtu",
                    "coal": "metric ton",
                    "electricity": "MBtu",
                    "fuelOil": "MBtu",
                    "naturalGas": "MBtu",
                    "propane": "MBtu",
                    "woodCord": "MBtu",
                    "woodPellets": "MBtu",
                    "monetary": "USD",
                    "emissions": "CO2"
                }
            }
        }

Response

            "globalControls": {
                "timelineStartDate": "2024-04-08",
                "debug": true,
                "includeInputs": true,
                "resolution": [
                    "monthly",
                    "annual"
                ],
                "includeBase": true,
                "includeTypical": true,
                "useFixture": false,
                "timelineDurationInYears": 1,
                "units": {
                    "monetary": "USD",
                    "electricity": "MBtu",
                    "naturalGas": "MBtu",
                    "woodPellets": "MBtu",
                    "propane": "MBtu",
                    "coal": "metric ton",
                    "emissions": "CO2",
                    "woodCord": "MBtu",
                    "energyStandard": "MBtu",
                    "fuelOil": "MBtu"
                }
            },
            "addressFull": "125 Douglas Dr, Jefferson City, MO 65109-0969",
            "baseBuilding": {
                "systems": {
                    "waterHeating": {
                        "waterHeatingSystems": []
                    },
                    "hvac": {
                        "hvacHeatingSystems": [
                            {
                                "heatLoadFraction": 1.0,
                                "heatEfficiency": 0.8,
                                "fuel": "natural gas",
                                "systemType": "furnace",
                                "id": "heating-systems-1",
                                "heatEfficiencyUnits": "AFUE"
                            },
                            {
                                "heatLoadFraction": 0.0,
                                "heatEfficiency": 0.67,
                                "fuel": "natural gas",
                                "systemType": "furnace",
                                "id": "heating-systems-2",
                                "heatEfficiencyUnits": "AFUE"
                            }
                        ],
                        "hvacCoolingSystems": [
                            {
                                "coolEfficiencyUnits": "SEER",
                                "coolLoadFraction": 0.9,
                                "coolEfficiency": 14.0,
                                "systemType": "central air conditioner",
                                "id": "cooling-systems-1"
                            },
                            {
                                "coolLoadFraction": 0.1,
                                "systemType": "room air conditioner",
                                "id": "cooling-systems-2"
                            }
                        ]
                    }
                },
                "enclosure": {
                    "airInfiltration": {
                        "rate": 1859,
                        "rateUnit": "CFM"
                    },
                    "walls": [
                        {
                            "assemblyEffectiveRValue": 12,
                            "id": "wall-insulation-1"
                        }
                    ],
                    "foundations": [
                        {
                            "type": "basement unconditioned",
                            "id": "floor-and-foundation-insulation-1"
                        }
                    ],
                    "attics": [
                        {
                            "floorAssemblyEffectiveRValue": 44,
                            "id": "attic-insulation-1"
                        }
                    ]
                },
                "buildingSummary": {
                    "conditionedFloorArea": 2256,
                    "yearBuilt": 1955,
                    "bedroomsCount": 3,
                    "averageCeilingHeight": 8
                }
            },
            "addressComponents": {
                "zipCode": "65109-0969",
                "addressLine1": "125 Douglas Dr",
                "stateAbbreviation": "MO",
                "city": "Jefferson City"
            },
            "errors": [
                {
                    "message": "[\"Warning: No dishwasher specified, the model will not include dishwasher energy use.\" \"Error: /tmp/modeling-api/hpxml-gen-outputs/NORMAL/01htzmatcd1gxhp7jq0zwz82m5/220006850_BASE.xml: Expected 1 element(s) for xpath: AnnualCoolingEfficiency[Units=\\\"EER\\\"]/Value [context: /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/CoolingSystem[CoolingSystemType=\\\"room air conditioner\\\"]]\"]",
                    "code": "openstudio-creating-input-unsuccessful"
                }
            ]
        }

[kellyatradiantlabs]

@lukeduran Since we have not built the underlying infrastructure to support multiple systems, the behavior is not always consistent with how they are handled. In this specific example, the second system in each of the arrays was getting read and processed. As a result, the room air conditioner ended up in the appliedBaseBuilding. A limitation that is currently missing from our docs is that EER is the only supported efficiency rating for room air conditioners (i.e. you can't define SEER for rooms ACs).

[lukeduran]

@kellyatradiantlabs, in this one, is the SEER from the Central AC being applied to the Room AC? In other areas of the API, when multiple systems are provided, it only takes the second one. I would expect in this case, it would take the Room Air Conditioner with no efficiency specified. Is that not the case?

[kellyatradiantlabs]

@lukeduran since we have not built the infrastructure to handle multiple systems yet, the code currently checks for any coolingEfficiency node. Its not setup to specifically handle and separate out different elements within an array yet. Thus, in this example, the SEER value that is designated for the Central AC is actually getting applied to the Room AC. (cc @joshuamzm)