Illustration: the graph on the tablet has been added and contains no measured consumption or heat-loss calculation.
Choosing the output of an infrared panel takes more than an area or volume table. The main mistake is treating a rough rule of thumb as a complete heat-loss calculation. Start with the goal: heating an entire room or supplementing one occupied position. Only then compare suitable panels and their positioning.
This guide is a preparation checklist, not a universal calculation tool. We discuss projects with private and business end users, installation companies and wholesalers. A substantiated design records assumptions and operating limits so you know which capacity is selected and why.
Key points
Square and cubic metres are both pieces of data, not a complete heat requirement. Calculate losses through the building envelope and ventilation under chosen design conditions. Then assess heat distribution, controls and electrical load. More output does not guarantee energy savings, while insufficient output can reduce comfort without changing the element’s conversion efficiency.
Distinguishing power, energy and comfort
Watts describe power; kilowatt-hours describe consumption over time. Rated electrical input is not the same as the radiant portion reaching a person in a particular position. A panel also emits convective heat. Use product data and assess desired heat distribution alongside total capacity.
An undersized installation may fail to reach the desired temperature in cold conditions. This does not justify a general statement that every small panel always consumes more energy or wears out faster. A larger system may deliver more comfort, but the comparison must concern the same goal. Arbitrary oversizing does not solve poor positioning or insulation.
Establishing the actual heat demand
Collect dimensions and areas of roof, floor, façades and glazing, with known insulation values. Include ventilation, air leakage, adjoining rooms and desired indoor temperature. The chosen design outdoor temperature partly determines the temperature difference for calculation. Construction year or energy label can provide information but does not replace these data.
A bathroom, bedroom and office may have different comfort goals, but they do not automatically receive a fixed temperature or watts per cubic metre. Discuss occupants, activity and warm-up time. With a high ceiling, building surfaces and positioning matter; a fixed percentage height adjustment does not replace a design and model-specific coverage data.
Five mistakes to check beforehand
1. Using a table as a complete calculation
Using only m² may miss information, but using only m³ does not solve that. Two rooms of the same volume can have different façades, windows, insulation and ventilation. Use rules of thumb only as a clearly labelled initial indication, and match the final selection to the specific room.
2. Seeing lower or higher wattage as a savings guarantee
Choose sufficient capacity for the agreed goal. Higher output operating for less time does not automatically use fewer kilowatt-hours for the same heat. Any reserve needs a design reason, such as a substantiated warm-up requirement. Also consider electrical load, controls and local intensity.
3. Skipping warm-up time and operating duration
Feeling the first radiation is not the same as bringing the entire room to temperature. Discuss when comfort is needed and how cold the room is initially. A motion sensor does not provide an instantly warm room on entry. Include the chosen controls and room response without promising a universal number of minutes.
4. Forgetting coverage and obstructions
Draw occupied positions and furniture on the plan. A panel behind a cupboard or curtain cannot freely reach the intended zone and may be incorrectly mounted. Choose wall or ceiling according to the room and model instructions. Do not simply increase wattage to compensate for an unsuitable position.
5. Considering controls and electrical capacity only later
Panel selection must suit the receiver, thermostat, switching load and the rest of the installation. Have simultaneous consumption and protective devices assessed. The sensor must measure representatively, and programmes must suit use. Suitable on-off control may suffice; more functions do not guarantee better sizing.
Recording a substantiated choice
Have assumptions, heat-loss results and chosen capacity recorded for each room. Ask how output is distributed across mounting positions and which model data were used. Several small panels may help coverage but are not always better than one suitable panel. Assess additional control, installation and maintenance costs.
Discussing product data and versions with us
Share a floor plan, insulation, desired temperatures and usage hours. We discuss possible versions and information with you and, where relevant, the installer or wholesaler. Design, metal or glass, and product origin do not replace capacity calculation. Also check model-specific mounting, warranty and maintenance before ordering.
Checks after commissioning
Test controls and comfort at occupied positions and record conditions and measurements. Disappointing results may also arise from sensor position, settings, air leakage or shielding. Do not automatically add more output. Have the cause assessed and update the plan if use or building conditions change.
Frequently asked questions
Can I simply add an extra percentage?
Not as a substitute for assessing the room. A reserve must have a purpose and be technically compatible with controls, heat distribution and installation. A fixed addition for each window, external wall or high ceiling may count the same losses twice or miss other factors. Have assumptions and any margin clearly substantiated.