Tool
Infrared heater power calculator
Work out how many units your patio needs.
POWER CALCULATOR
Work out how many Opranic infrared heaters you need
Choosing the right number of infrared heaters should not come down to guesswork. Our infrared heater power calculator combines real-world temperature measurements with physics-based heat distribution to give you a concrete recommendation in 30 seconds.
Enter the dimensions of your patio, balcony or conservatory and the calculator works out the estimated comfort output and recommends the number of Opranic 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 warmth reaches.
The result appears in a top-down visualisation where each heater’s coverage is drawn from actual measured values. You see immediately whether your area is adequately covered and what it costs to run the heaters 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 Opranic power calculator works
Rather than relying on generic rules of thumb such as “150 W per square metre”, the Opranic infrared heater power calculator is built on three factors that genuinely determine how radiant warmth travels:
1. Real-world temperature measurements
Opranic has measured the surface temperature produced by the PRO V70 at distances from 1 to 5 metres, against a matte black timber background, in 19 °C still air. The results, from 95 °C at one metre down to 25 °C at five metres, form the basis of the heat coverage shown by the Opranic calculator. The full measurement series is plotted in the graph further down the page.
2. Physics-based modifiers
Range is shaped by the environment. An exposed terrace loses more warmth to the wind than a glazed conservatory. A high mounting position spreads the radiation more thinly. Lower outdoor temperatures call for more power. The Opranic calculator adjusts the range in real time as you change each parameter.
3. Triac-controlled power regulation
The Opranic PRO V70 offers five power settings, P1 to P5, corresponding to 40, 55, 70, 85 and 100 percent of the 2,300 W maximum output. This is not a linear dimmer. The Opranic power calculator computes the running cost at each P setting based on the actual wattage drawn and the electricity price you enter.
The difference from theoretical range
The Opranic visualisation shows two zones. The coloured zone is the perceived comfort zone, where you genuinely feel the warmth, adjusted for your environmental settings. The dashed rings beyond it mark the theoretical maximum radiation range, where heat is still present but so faint that it is barely noticeable.
FREQUENTLY ASKED QUESTIONS
Infrared heater power calculator: your questions answered
How many Opranic infrared heaters do I need for 20 m²?
It depends on mounting height, wind exposure and whether you have a roof. For a typical 20 m² patio with a pergola and partial wind shelter, the Opranic infrared heater power calculator usually recommends 2-3 Opranic PRO V70 units at P3-P5. Use the calculator above for an exact recommendation based on your specific space.
What is the difference between wall and ceiling mounting?
Wall mounting directs warmth from the side and suits patios with one or two walls. Ceiling mounting spreads warmth more evenly across the whole area and suits pergolas or covered roofs. The Opranic PRO V70 is approved for both. In the Opranic calculator you can switch between the two and see how the heat distribution changes.
What does it cost to run an Opranic infrared heater per hour?
At 2 kr/kWh, the Opranic PRO V70 costs around 1.84 kr/h on P1 (lowest) and 4.60 kr/h on P5 (full power). Two Opranic heaters on P3 (mid setting) come to around 6.44 kr/h. The calculator shows the exact running cost for your configuration and updates instantly when you change the electricity price or P setting.
Does wind affect how far the warmth reaches?
Yes, significantly. Infrared radiation travels the same distance regardless of wind, but the warm air layer that forms around your skin is carried away on an exposed patio. The Opranic calculator models this through the wind shelter setting; exposed locations show up to 18% shorter effective reach compared with fully sheltered positions.
Can I use the Opranic calculator for the THOR S70?
Technically yes. The Opranic THOR S70 uses the same IR-X Carbon Black radiation and the same maximum power as the Opranic PRO V70. The difference is that the THOR S70 is freestanding and sits on the floor, so furniture, plants and objects in front of the heater can block the radiation, making the practical reach slightly shorter. Use the Opranic calculator as a guideline and allow for 10-20% shorter effective reach.
How accurate are Opranic’s measured values?
The measurements are taken against matt black plywood, a surface that absorbs almost all incoming infrared radiation. In practice, human skin, clothing and ordinary surfaces absorb less, so the perceived warmth at the same distance is slightly lower than the raw measurement series suggests. The comfort zone in the Opranic calculator (the coloured zone) already accounts for this.
IN DEPTH
Learn more about infrared heating
Want to understand the engineering behind the calculator? Explore our guides to Opranic infrared heaters:
- What is infrared heating? A complete guide to how infrared radiation works and why it differs from convection heating.
- How infrared heating works. The physics behind the Opranic IR-X Carbon Black emitter and why 2.2 µm is the optimal wavelength for outdoor heating.
- Outdoor infrared heaters, a buyer’s guide. A side-by-side comparison of the Opranic THOR S70, NOVA V50 and PRO V70 across different applications.
- Gas patio heaters vs infrared heaters. Running cost, environmental impact and the practical differences between the two technologies.