[{"data":1,"prerenderedAt":147},["ShallowReactive",2],{"example-air-conditioner-en":3,"faq-air-conditioner-en":109,"sources-air-conditioner-en":143},{"input":4,"output":20},{"location":5,"roomVolumeM3":6,"envelopeAreaM2":7,"insulation":8,"windowAreaM2":9,"windowOrientation":10,"shadingFactor":11,"outdoorDesignTempC":12,"indoorTargetTempC":13,"occupants":14,"equipmentW":15,"airChangesPerHour":16,"applianceType":17,"ratedEer":18,"averagePartLoadRatio":16,"operatingHoursPerDay":19},"52.52,13.405",60,80,"moderate",4,"south",0.7,32,24,2,200,0.5,"inverter",3.2,8,{"transmissionLoadW":21,"solarGainW":22,"internalGainW":23,"ventilationLoadW":24,"totalCoolingLoadW":25,"recommendedCapacityW":26,"effectiveEer":27,"electricalPowerW":28,"dailyEnergyWh":29,"site":30,"alternativeDailyEnergyWh":36,"chain":37,"steps":59,"warnings":80},384,700,400,81.60000000000001,1565.6,1800.4399999999998,3.4128728896216205,458.733756173842,2363.4760915913166,{"designTempC":31,"partLoadRatio":32,"operatingHoursPerDay":33,"coolingHoursPerYear":34,"annualElectricityKwh":35},30,0.5565148132882904,5.1521739130434785,474,154.34964752402908,2835.023858231509,[38,51],{"module":39,"derived":40},"load-profile",[41,46],{"field":42,"value":43,"rationale":44,"provenance":45},"coolingLoadFromEnvelope",true,"rationale.ac.loadFromEnvelope","exact",{"field":47,"value":48,"rationale":49,"provenance":50},"capacityMargin",1.15,"rationale.ac.margin","assumed",{"module":52,"derived":53},"array-sizing",[54],{"field":55,"value":56,"rationale":57,"provenance":45,"unit":58},"dailyEnergyWh",2363,"rationale.ac.dailyFromLoad","Wh\u002Fd",[60,64,67,70,73,77],{"label":61,"expression":62,"value":21,"unit":63,"provenance":50},"transmissionLoad","U * A * (T_aussen - T_innen)","W",{"label":65,"expression":66,"value":22,"unit":63,"provenance":50},"solarGain","A_Fenster * g * Verschattung",{"label":68,"expression":69,"value":24,"unit":63,"provenance":45},"ventilationLoad","n * V * c_Luft * (T_aussen - T_innen)",{"label":71,"expression":72,"value":25,"unit":63,"provenance":45},"totalCoolingLoad","Summe aller Waermeeintraege",{"label":74,"expression":75,"value":27,"unit":76,"provenance":50},"effectiveEer","EER_nenn * Teillastfaktor","",{"label":78,"expression":79,"value":29,"unit":58,"provenance":45},"acDailyEnergy","Q_gesamt \u002F EER_wirksam * Betriebsstunden",[81,89,97,102],{"level":82,"code":83,"params":84,"anchors":87},"info","APPLIANCE_TYPE_MATTERS",{"type":17,"difference":85,"percent":86},472,20,[88],"applianceType",{"level":82,"code":90,"params":91,"anchors":94},"COOLING_LOAD_DOMINATED_BY",{"source":92,"share":93},"solar",45,[95,96],"windowAreaM2","insulation",{"level":82,"code":98,"params":99,"anchors":100},"SHADING_CHEAPER_THAN_COOLING",{"gain":22},[101],"shadingFactor",{"level":82,"code":103,"params":104,"anchors":107},"AC_LOAD_FROM_SITE",{"temp":31,"hours":34,"plr":105,"kwh":106},56,154,[108],"location",[110,113,116,119,122,125,128,131,134,137,140],{"q":111,"a":112},"What cooling capacity does my room actually need?","The calculator estimates the cooling load from the building envelope: transmission via U-value and envelope area, solar gain via window area, orientation and shading, internal gains from people and equipment, plus air changes. A 15 percent margin is added to the total — deliberately no more, because an oversized unit cycles more and dehumidifies worse.",{"q":114,"a":115},"Inverter air conditioner or on-off unit — which uses less energy?","At part load, the inverter unit: it slows the compressor down instead of switching off and so runs closer to its design point — at an average part-load ratio of 0.5 that is roughly 20 percent less daily consumption. What matters is the average part-load ratio over the operating period, not the design day: the unit is sized for the hottest day, and on an average day the load runs at about half of that.",{"q":117,"a":118},"How accurate is the cooling load estimate from an insulation standard?","The U-values per insulation standard are guide figures for pre-selection, not a code table. The calculation is valid for a single room on the design day in steady state; building thermal mass and the resulting time shift of the load, the dehumidification share, distribution losses and the specific unit's performance curve over outdoor temperature are not covered.",{"q":120,"a":121},"Why is shading cheaper than more cooling capacity?","In the example, 700 of the 1,566 W cooling load — 45% — enters through the south window. External blinds cut the shading factor from 0.7 to about 0.25 and remove several hundred watts of continuous load before the first kilowatt-hour is cooled. Every avoided watt of cooling load saves three to four times that in solar power, because it has to be traced back through the EER and the solar chain. That is why the calculator explicitly names the largest load source.",{"q":123,"a":124},"How big is the difference between inverter and on-off units really?","In the example room the inverter unit uses 3,641 Wh per day, the on-off unit 4,473 Wh — about 23% more. The difference arises almost entirely under part load: the cycling unit loses energy on every start and is only efficient at full load, while the inverter slows its compressor down and even gains slightly under part load. Since an air conditioner is sized for the hottest day, it runs in part load on almost every other day.",{"q":126,"a":127},"How much solar power does a solar-run air conditioner need?","As a rule of thumb: divide the daily consumption by the peak sun hours of the cooling month and the chain efficiency. For the example’s 3,641 Wh at summery 4.5 PSH and 70% chain that is about 1,160 Wp. The big advantage of air conditioning as a solar load: cooling demand and solar yield coincide — at midday, when the sun creates the load, it also delivers the power. The hand-off link passes the daily consumption straight to the panel-sizing calculator.",{"q":129,"a":130},"How many hours a year does an air conditioner actually run?","In central Europe far fewer than the purchase price suggests. For a 60 m³ room with 4 m² of south-facing glazing in the Berlin region the calculator finds 474 cooling hours a year — spread over the summer months that is about 5.2 hours a day, not the 8 often assumed. That number decides the running cost, and it is no longer an estimate: it follows from the hourly temperatures of the site.",{"q":132,"a":133},"How much electricity does an air conditioner use per year?","About 145 kWh in the reference case — for a single room with an inverter unit in the Berlin region. That is considerably less than the rated power suggests, because the unit only runs for a few hundred hours a year and averages 56 % part load while doing so. For sizing the solar system the peak still matters: it occurs at midday, exactly when the PV delivers.",{"q":135,"a":136},"Why is a west-facing window worse than a south-facing one?","Because the heat arrives at the wrong time. The calculator puts the irradiance on the vertical window plane, where south peaks at midday but west peaks in the late afternoon — when the outdoor temperature reaches its daily maximum. The two add up. In the example the cooling load rises from 1,398 W (south) to 1,538 W (west), and the design point shifts from 30 to 34 °C outdoor temperature.",{"q":138,"a":139},"What cooling capacity does my room need?","For the example room 1,607 W with south glazing and 1,768 W with west glazing — each with 15 % reserve on the computed cooling load. Rules of thumb based on room size alone mislead, because with moderate insulation the solar gain through the windows is the largest single item. A north-facing window brings the same room down to 995 W.",{"q":141,"a":142},"Is shading worth more than a bigger air conditioner?","Almost always. Solar gain enters the cooling load linearly, and external shading cuts the shading factor drastically. The calculator carries it as its own field so the comparison is visible: dropping the factor from 0.7 to 0.25 saves more cooling load than any efficiency class of the appliance delivers — and the investment is one-off rather than permanent in the electricity bill.",[144],{"name":145,"url":-1,"retrievedAt":146,"version":-1},"Aggregate of manufacturer datasheets, the EU energy label database EPREL and measurement series from off-grid practice","2026-07-15",1786101755802]