Instrumentation System for a Rapid-Recovery Water Heater

Abstract

This work presents an instrumentation system developed for the experimental acquisition and monitoring of the main thermal and hydraulic variables of a rapid-recovery water heater. The system uses two externally mounted NTC thermistors to measure inlet and outlet pipe temperatures, a Hall-effect sensor to measure water flow, an STM32 microcontroller for data acquisition, an NI TC-01 module for reference temperature measurement, and a LabVIEW interface for real-time visualization and data storage. The experimental procedure considered heating, steady-state, and cooling conditions combined with zero, low, and high waterflow levels. We acquired 120 experimental records at 5 Hz, collecting 1200 samples during each 240 s test. The measurements captured the water heater's thermal and hydraulic behavior under different operating conditions without modifying the original water path. The resulting dataset provides a structured basis for subsequent analysis of outlet-temperature behavior and future temperature-estimation strategies.