~ Summary ~

We evaluated the energy efficiency of a graphene underfloor heating panel by measuring temperature rise against power input across a voltage range of 8V to 48V. Results revealed peak efficiency at mid-power levels (20–30V) with expected diminishing returns at higher voltages. Thermography confirmed accurate surface temperature readings, providing our Client with key data on thermal performance and energy suitability for controlled environments.

Thermography UK-Energy Efficiency Testing of Graphene Underfloor Heating Panel

Introduction

As part of an ongoing thermographic analysis programme for our Client, we undertook a focused study to assess the energy efficiency of their graphene-based underfloor heating panel. This specific investigation aimed to quantify how much thermal output (temperature rise) the panel delivers per watt of electrical energy consumed across a range of voltages and power levels. The findings would determine its suitability for energy-efficient applications and help define its performance curve under real-world conditions.

Testing Location & Process

All work was conducted at our studio under controlled environmental conditions. The panel (600mm x 530mm) was powered using a regulated DC bench supply and mounted on an insulated test platform. With ambient air stabilised at 16°C and no solar influence, we applied incremental voltage steps (8V to 48V) without allowing cool-down periods in between, mimicking continuous-use behaviour.

Surface temperatures were measured using a high level thermal camera positioned 1 metre above the panel, while current and voltage were simultaneously recorded using a clamp multi-meter. At each voltage step, temperature readings were captured at 1, 5, and 10-minute intervals to assess how thermal output changed over time and across power inputs.

Project Subjects

"Graphene Heating, Thermal Efficiency, Underfloor Heating, Power Consumption, Thermographic Testing, Product Testing with Thermography"

Project Skills

Energy Efficiency Profiling through ΔT/W analysis Controlled Thermal Imaging with Environmental Stabilisation Temperature-Time Correlation using FLIR Camera + Thermocouple Cross-Reference

Report Writing Service

raphene, Underfloor Heating, Power Testing, Energy Efficiency, Thermal Output, Voltage Ramp, Heat Profiling, Thermography

Key Observations and Findings

The results showed that below 10V, the panel produced negligible or negative temperature rise due to natural cooling exceeding the heating effect. From 20V upwards, thermal output began to register, with the most efficient range found between 20V and 30V.

  • Maximum Efficiency recorded was 0.16°C per Watt at 20V (6.8W)

  • Diminishing returns were observed at higher voltages—at 48V (45W), efficiency reduced to ~0.10°C/W

  • 8V and 10V tests showed either no temperature gain or a slight drop, attributed to convective cooling

  • Efficiency Calculated using temperature rise from starting baseline for each step (ΔT ÷ W)

  • Surface temperatures peaked at 28.4°C after 10 mins at 48V, compared to the 16°C ambient

This profile is consistent with typical resistive heating behaviour: higher wattages create faster and greater temperature increases, but thermal efficiency begins to reduce due to heat loss mechanisms like convection and radiation.

Outcome & Interpretation

The results offer clear insight into the thermal response and energy efficiency of graphene-based underfloor heating technology. Optimal thermal efficiency was achieved in the mid-range power levels (20–30V), aligning with the practical requirements for energy-conscious building environments.

Thermographic testing confirmed that efficiency naturally declines as the system nears its power ceiling, supporting the idea that smart control systems may benefit from regulating voltage to maintain efficient performance zones.

This analysis provides our Client with a verified power-to-heat performance map for their heating panels, supporting engineering decisions for product development and deployment in commercial and residential applications.

FLIR CM85-2 Clamp Multi Meter
FLIR MR77 Temperature Meter

Summary

This power-to-heat efficiency test revealed a clear performance curve for the graphene underfloor heating panel. Thermal output began only once a sufficient power threshold was met (from 20V upwards), confirming that low-voltage operation (8V–10V) delivers no meaningful heating effect due to ambient cooling dominance.

Peak efficiency was recorded at moderate power inputs, where the temperature rise per watt was highest. As voltage and power increased further, thermal efficiency declined, consistent with the natural behaviour of resistive heating systems. These findings are valuable for optimising the energy strategy of the panel in practical use.

  • No heating effect at 8V and 10V – surface temperature dropped due to ambient convective cooling.

  • Minimum effective operating threshold begins at 20V, delivering measurable heat gain.

  • Peak thermal efficiency of 0.16°C per Watt recorded at 20V (6.8W input).

  • Efficiency declined steadily from 30V to 48V due to increasing thermal losses at higher power levels.

  • Maximum temperature reached was 28.4°C after 10 minutes at 48V (~45W input).

  • Efficiency formula used: Temperature gain above step-start ÷ power input (ΔT/W).

  • No rest period between steps mimicked continuous use – more realistic operational behaviour.

  • Highest efficiency zone identified between 20V and 30V, ideal for energy-optimised usage.

  • Thermal imaging confirmed accurate ΔT readings, validated by supporting thermocouple measurements.

  • Graphene panel demonstrated reliable heat response scaling with voltage, confirming suitable real-world controllability.