Noncontact Measurement of Thermal Resistance in 3D Concrete Printing Building Envelopes Using Infrared Sensing and Arduino (2025-11)¶

Thermal resistance (R-value) is a key metric for evaluating the energy performance of building envelopes, particularly in emerging technologies like 3D-concrete pinting (3DCP) buildings. However, conventional methods such as heat flux meters (HFM) face challenges in 3DCP applications due to surface roughness, contact-based limitations, and high costs. This study introduces a novel low-cost, noncontact system integrating an MLX90614 infrared sensor and LM35 temperature sensor with an Arduino-based platform, using the Thermometric Method (THM) to estimate R-values from wall surface, indoor, and outdoor temperatures. A novel feature of the system is a dual-servo mechanism that enables spatial temperature mapping over a 5 × 5 cm grid, improving accuracy by replacing traditional single point measurements with area-based readings. Validation against the UVAL Wireless System (greenTEG) showed a maximum error of 13% under steady-state early morning conditions, increasing to 173% in the afternoon due to thermal instability. The proposed method offers a practical, affordable, and non-destructive solution for thermal diagnostics in 3DCP buildings, supporting the development of standardized evaluation protocols for sustainable construction.