The decarbonization of industrial heating systems is one of the major challenges of the current energy transition. Gas-fired radiant tubes dominate industrial heating in large-span, high-bay buildings due to their high efficiency and low operating costs; however, the absence of equivalent electric solutions capable of replacing them represents a significant technological and scientific gap. This paper presents the design, construction, and experimental characterization of an innovative electric radiant tube prototype developed within the INFRAEL research project. The prototype consists of a 100 mm diameter steel tube housing nickel–chromium resistive elements in various configurations, powered from a 230 V AC supply. Thermal measurements were performed using Type K thermocouples distributed along the tube, a non-contact infrared thermometer, and thermovision imaging, complemented by MATLAB R2025bTrial-based interpolation for mapping the thermal field on a receiving plane placed 2 m below the tube. Experimental results show that at a total power of ~1.2 kW (two resistors in parallel), the tube surface reaches temperatures exceeding 250 °C, corresponding to medium-wave infrared emission (~4 μm). A single 630 W resistor yields surface temperatures of approximately 136–160 °C. The temperature distribution on the receiving plane is relatively uniform. The study identifies key optimization directions—resistor geometry, thermal insulation, and integration with photovoltaic sources—with the goal of developing a competitive, zero-carbon alternative to gas-fired radiant heating systems in industrial environments.

The electrification of residential heating through heat pumps represents one of the central directions of the European energy transition; however, evaluating these systems requires moving beyond classical approaches limited to purely energy-based indicators. This paper proposes an integrated 3E analysis (Energy–Economy–Environment) of a hybrid system composed of a split-type air-to-water heat pump (nominal heating capacity of 8 kW, R410A refrigerant) and an on-grid photovoltaic installation with a peak power of 6.02 kWp, installed in a single-family house with a usable floor area of 122.3 m², located in climatic zone II with a conventional winter design outdoor temperature of t_ext = −15 °C. Operational data, collected over two consecutive heating seasons (2024–2025 and 2025–2026) at daily resolution and aggregated monthly, were processed to determine the seasonal performance factor (SPF), the specific heat demand, the operating costs compared with a conventional natural-gas solution, and the climatic impact through the TEWI (Total Equivalent Warming Impact) indicator. The results show SPF values of 3.30–3.51 (±7%, standard uncertainty), a strong correlation between outdoor temperature and COP (at both the monthly and daily levels), average annual savings of approximately 2834 RON compared with the natural-gas solution, and a payback period of 15–16 years. The cumulative climatic impact over the equipment’s lifetime (TEWI ≈ 35.1 t CO₂-eq over 15 years) is offset to a large extent (≈83%) by the emissions avoided through photovoltaic production (≈29.25 t CO₂-eq). The results indicated a higher LCCP (Life Cycle Climate Performance) compared with TEWI, by approximately 4.0%, for the system presented in this paper. The study also identifies limitations associated with the local electricity grid infrastructure, which reduce the exploitation of photovoltaic production during periods of high solar potential, and proposes optimization directions such as battery storage and improvements to the building envelope. The results support the need for multicriteria, 3E/4E-type assessments to underpin decisions on the decarbonization of the residential building sector.