Tools
Infrared Heater Power Calculator
Calculate how many you need for your patio.
POWER CALCULATOR
Calculate how many infrared heaters you need
Choosing the right number of infrared heaters is not about guesswork. Our infrared heater power calculator combines real temperature measurements with physics-based heat distribution to provide you with a concrete recommendation in 30 seconds.
Enter your patio, balcony, or outdoor room and the calculator will determine the estimated comfort output and recommend the number of PRO V70 units. You can adjust placement, mounting (wall or ceiling), and environmental factors such as wind protection and outdoor temperature—all parameters that affect how far the heat reaches.
The result is displayed in a top-down visualization where each heater’s distribution is drawn based on actual measurements. You can immediately see if your area is sufficiently covered and what it costs to run the heat per hour.
Räkna ut effektbehov för din infravärmare utomhus
Ange din terrass, balkong eller uterum så räknar vi ut beräknad komforteffekt och rekommenderar antal PRO V70 för vägg- eller takmontering.
Din yta
Dra reglagen till storleken på din terrass eller balkong.
Höjden där värmaren monteras över marken. Standard 2,2 m fungerar för de flesta terrasser.
Din miljö
Välj hur ytan är skyddad och vid vilken temperatur du vill värma upp.
Den utetemperatur du vill kunna sitta ute i. 10 °C är ett vanligt vår- och höstvärde.
Justera kalkylen (valfritt)
Vår rekommendation till höger är redan beräknad. Vill du jämföra alternativ kan du justera nedan.
Vägg = monterad på husfasad eller staket. Tak = monterad i pergola eller takkonstruktion.
Triac-styrd effekt per värmare. P5 = full effekt (2 300 W) är default och visar maxkapacitet. P3 (1 610 W) räcker oftast i vår och höst och kostar ca 30% mindre i drift.
Auto väljer optimalt antal för din yta. Du kan också välja själv.
Klicka själv = du placerar värmarna manuellt på ritningen till höger.
Ritningen uppdateras när du justerar inställningarna till vänster. Välj Klicka själv i steg 3 om du vill placera värmarna manuellt.
| Avstånd | Yttemp | Δ mot luft |
|---|---|---|
| 1,0 m | 95 °C | +76 °C |
| 1,5 m | 57 °C | +38 °C |
| 2,0 m | 45 °C | +26 °C |
| 2,5 m | 38 °C | +19 °C |
| 3,0 m | 32,5 °C | +13,5 °C |
| 4,0 m | 28,5 °C | +9,5 °C |
| 4,5 m | 27 °C | +8 °C |
| 5,0 m | 25 °C | +6 °C |
Mätningen är ett benchmark som visar hur värmaren presterar i kontrollerad miljö mot en perfekt absorberande yta. I praktiken absorberar mänsklig hud, kläder och vanliga ytor mindre än matt svart playwood, så den upplevda värmen vid samma avstånd blir något lägre. Utomhus tillkommer dessutom konvektionsförluster (vind kyler huden) som modellen kompenserar för via inställningarna ovan.
METHOD
How the power calculator works
Unlike general rules of thumb such as “150 W per square meter,” our infrared heater power calculator is based on three factors that actually determine how heat is distributed:
1. Real temperature measurements
We have measured the surface temperature from the PRO V70 at distances of 1 to 5 meters against a matte black wood background at 19°C air temperature, with no wind. The results—from 95°C at 1 meter distance down to 25°C at 5 meters—form the basis for the heat distribution shown by the calculator. You can see the complete measurement series in the graph further down the page.
2. Physics-based modifiers
The range is affected by the environment. An exposed patio loses more heat to the wind than an enclosed veranda. High installation height spreads the heat more thinly. Lower outdoor temperatures require more power. The calculator adjusts the range in real time when you change these parameters.
3. Triac-controlled power regulation
The PRO V70 has five power modes—P1 to P5—corresponding to 40, 55, 70, 85, and 100 percent of the maximum output of 2,300 W. It is not a linear dimmer. The calculator calculates the operating cost for each P mode based on the actual wattage and the electricity price you enter.
The difference from theoretical range
In the visualization, you see two zones. The colored zone is the perceived comfort zone where you actually feel the heat clearly, adjusted according to your environmental settings. The dashed rings outside are the theoretical maximum radiation range—where the heat exists but is so weak that it is barely noticeable.
FREQUENTLY ASKED QUESTIONS
Questions about the infrared heater power calculator
How many infrared heaters do I need for 20 m²?
It depends on height, wind protection, and whether you have a roof. For a typical outdoor patio of 20 m² with a pergola and partial wind protection, the calculator usually recommends 2-3 PRO V70 units at P3-P5. Use the calculator above for an exact recommendation based on your specific area.
What is the difference between wall and ceiling mounting?
Wall mounting directs the heat from the side and is suitable for patios where one or two walls are present. Ceiling mounting provides more even distribution over the entire area and is suitable for pergolas or roofs. The PRO V70 is approved for both mounting methods. In the calculator, you can switch between them and see how the heat distribution changes.
What does it cost to run an infrared heater per hour?
At 2 SEK/kWh, the PRO V70 costs approximately 1.84 SEK/h at P1 (lowest) and 4.60 SEK/h at P5 (full power). Two heaters at P3 (medium setting) cost approximately 6.44 SEK/h. You can see the exact operating cost for your configuration in the calculator—it updates immediately when you change the electricity price or P mode.
Does wind affect how far the heat reaches?
Yes, significantly. Infrared radiation reaches the same distance regardless of wind, but the warm air that forms around the skin is blown away on an exposed patio. The calculator models this through the wind protection setting—exposed areas receive up to 18 percent shorter effective range compared to fully protected locations.
Can I use the calculator for the THOR S70?
Technically yes—the THOR S70 has the same IR-X Carbon Black radiation and the same maximum output as the PRO V70. The difference is that the THOR S70 is freestanding and placed on the floor. This means that furniture, plants, and objects in front of the heater can block the radiation, so the practical range becomes somewhat shorter. Use the calculator as a guideline and expect 10-20 percent shorter effective range.
How accurate are the measurements?
The measurements were taken against matte black plywood—a surface that absorbs almost all infrared radiation. In practice, human skin, clothing, and common surfaces absorb less, so the perceived heat at the same distance will be somewhat lower than what the measurement series shows. The calculator’s comfort zone (the colored zone) takes this into account.
IN-DEPTH
Learn more about infrared heating
Want to understand the technology behind the calculator? Here are our guides on infrared heating:
- What is infrared heating? —a complete guide on how infrared radiation works and why it differs from convection heating.
- How infrared heating works—the physics behind the IR-X Carbon Black emitter and why 2.2 µm is optimal for outdoor heating.
- Outdoor infrared heaters—buying guide—comparison between THOR S70, NOVA V50, and PRO V70 for different applications.
- Gas heaters vs infrared heaters—operating costs, environmental impact, and practical differences between the technologies.