1Purpose2Location3Building4Installation5Refine6Bills7Rooms8Partitions9Technical10Ranking

Start hereWhat should the system do?Choose what the system should do — the following questions and the selection depend on it.

Air conditioningAir conditioning + supplementary heatingAir conditioning + heatingHeat pump — central heatingHeat pump — central heating + DHW

Air conditioning selectionHeat pump selection

RequiredWhere is the building located?Enter the location — we derive the climate zone and design temperature from it.

City or postal codePostal code will be recognized automatically; outside the database, a zone can be entered.

CountryCountryEmergency zoneEmergency zone

Design temperature

Design temperature°C

RequiredArea and standardArea, height and building standard are the basis for the demand calculation.

Heated aream²Heated areaAverage heightmAverage height

Building standard

Passive / airtightNew, compliant with current requirementsAfter solid thermal modernizatione.g. 90s, approx. 10 cm insulationOld, poorly insulated

WindowsWindowsAdd window

Required · result after this stepInstallationThe installation type sets the supply temperature, and the number of people the DHW demand.

Installation

Underfloor heatingMixed installationNew radiatorsRadiatorsOld radiators

Number of DHW usersThe system determines the supply temperature, and the number of people determines DHW demand.Indoor temperature°CThe temperature you want to maintain indoors (usually 20–22 °C).

Largest additional accuracy gainHighest impact questions firstA few questions with the largest impact on the result — ventilation, building shape and adjacent structures.

VentilationVentilationBuilding typeBuilding typeWhat is above the top floor?What is above the top floor — affects heat loss through the roof.What is under the building?What is beneath the building — affects heat loss through the floor.

CalibrationDo you have bills or observations?Have bills or your own observations? We'll calibrate the selection with your real consumption.

No data availableElectricityFuelEU indexObservation

Bill amountBy default, we rank by electricity consumption (kWh/year). Prices are not converted into a bill — we do not know your tariff.BillsThe period the entered bill or consumption refers to.

Room design — can be skippedHeating zonesList the rooms if you want power split zone by zone — can be skipped.

+ Add room

OptionalPartitions to the centimeterBuilding-element details to the centimeter narrow the result — all fields are optional.

Wall materialWall materialWall thicknessWall thicknessWall insulationWall insulationWall insulation thicknessWall insulation thicknessWindowsEnter total window area — for heating, the total m² matters (windows lose 4–8× more than walls, affecting sizing). Cardinal direction is irrelevant here. Empty = calculated from glazing ratio.Roof insulationRoof insulationRoof insulation thicknessRoof insulation thicknessFloor insulationFloor insulationFloor insulation thicknessmFloor insulation thickness

Optional — can be skippedTechnical conditions and environmentTechnical conditions and surroundings — supply temperature, limits and boiler-room data.

No dataI have a project, a buffer tank nameplate, or I know what is in the boiler room.

Supply°CThe system determines the required supply temperature.Night power limitAOnly if you have a mandatory night limit, e.g., from zoning conditions. If you don't know — leave empty.

Last stepHow to rank the results?Final step: set how to sort the results and whether to limit them to selected brands.

SortingBy default, we rank by electricity consumption (kWh/year). Prices are not converted into a bill — we do not know your tariff.BrandLimit the ranking to selected manufacturers.Max. reserveExtra power reserve above the calculated demand.

Strict modeCautious mode

Update selection

EuroventPerformance certification

EPRELEU energy label database

KatalogiManufacturer data