Analisa kinerja FCU menggunakan diagram psikrometri

Air Handling Unit (AHU) ataupun Fan Coil Unit, sebagai salah satu sistem untuk pemanasan dan pendinginan ruang untuk sismtem HVAC. AHU/FCU menjadi salah satu pendukung dari konsumsi energi di gedung-gedung yang menggunakan sistem HVAC terutama jenis AC Central. Sistem HVAC mengkonsumsi sekitar 60% dari seluruh konsumsi energi dalam sebuah hunian/gedung konsumen energi tunggal terbesar di gedung komersial, sehingga perlu upaya penghematan energi untuk menghemat sumber daya, mengurangi polusi dan emisi CO2 ke lingkungan. Artikel ini membahas tentang FCU yang digunakan pada AC central dan melakukan perhitungan performnsi pada FCU. Pengukuran performansi FCU dilakukan dengan tujuan mengukur konsumsi energi sistem FCU, kualitas udara dalam ruangan dan kenyamanan termal di FCU Perhitungan performansi dengan menggunakan diagram Psikrometrik dapat digunakan sebagai acuan untuk melakukan penghematan energi. Perhitungan yang dilakukan dengan metodologi ini dapat diperbaiki dengan memperhatikan faktor beban peralatan tambahan dan efisiensi peralatan tambahan untuk mendapatkan hasil yang lebih tepat dan akurat. Penggunaan program simulasi dapat digunakan sebagai validasi dari perhitungan secara manual untuk mendapatkan hasil yang lebih tepat dan akurat untuk perbaikan performansi FCU.

Design and Operation of a Polygeneration System in Spanish Climate Buildings under an Exergetic Perspective

This work defines and analyzes the performance of a polygeneration system in five different locations in Spain to maintain the thermal comfort and air quality of an office building. The facility is based on a chiller and a CHP engine with PV panels that provide almost all the electricity demand of the chiller. According to the energy performance analysis results, the installation working in Bilbao is a full polygeneration system since no electricity needs to be imported from the grid in summer. To quantify the energy savings related to a separated production facility, polygeneration indicators (percentage of savings PES/PExS and equivalent electric efficiency EEE/EExE) have been calculated in energy and exergy terms. The main motivation for using exergy is based on the ambiguity that can arise from the point of view of the First Law. As expected, the exergetic indicators have lower values than the energetic ones. In addition, an in-depth analysis was conducted for the air-handling unit components. The study shows the behavior of components over the year and the efficiency values from both an energy and exergy point of view. From these facts, the need arises to develop methodologies based on exergy.

Towards an intelligent HVAC system automation using Reinforcement Learning

HVAC systems are among the biggest energy consumers in buildings and therefore in the focus of optimal control research. In practice, rule-based control and PID controllers are typically used and implemented at the beginning of the building operation. Since this approach neither guarantees optimal or even good control, optimal control algorithms (which can be predictive and adaptive) are in the focus of research. The problem with most of the approaches is that a model of the system is often needed which comes with high engineering efforts. Further, the required computing power can quickly exceed the capacities, even in modern buildings. Therefore, in this paper we investigate the application of a state-of-the-art Reinforcement Learning (RL) algorithm, as a self-calibrating valve controller for two water-air heat exchangers of a real-world air handling unit. We choose a generic problem formulation to pre-train the algorithm with a simulation of an admixing heater and use it to control an injection heater and a throttle cooler. Our results show that after only 70 hours, the control quality significantly increases. Therefore, it seems evident that with pre-trained RL algorithms, a self-improving HVAC automation can be realized with little hardware requirements and without extensive modelling of the system dynamics.

Preliminary symptoms assessment of typical faults related to the fans and humidifiers of HVAC systems based on experimental data collected during Italian summer and winter

The symptoms associated to the occurrence of typical faults in a heating, ventilation and air-conditioning (HVAC) system, including a single duct dual fan constant air volume air-handling unit, have been experimentally characterized. The operation of the HVAC unit with 3 artificially forced faults ((1) reduced velocity of the supply air fan, (2) reduced velocity of the return air fan, (3) the valve supplying the humidifier kept always closed) has been analysed and compared with that of healthy operation of the same plant under very similar boundary conditions (outside air temperature and initial indoor air temperature) during Italian summer and winter in order to preliminarily assess (i) the effects on the main operating parameters, and (ii) generate preliminary operation data to assist further research in fault detection and diagnosis of HVAC systems.