Energy demand reduction in pharmaceutical cleanrooms through optimization of ventilation

M.G.L.C Loomans,P.C.A Molenaar,H.S.M Kort,P.H.J Joosten

doi:10.1016/j.enbuild.2019.109346

M.G.L.C Loomans, P.C.A Molenaar + Show 2 more

Open Access

https://doi.org/10.1016/j.enbuild.2019.109346

Copy DOI

Abstract

The high Air Change Rates (ACRs) required for cleanrooms makes them energy intensive. This research elaborates on three strategies for energy efficient ventilation in pharmaceutical cleanrooms: Fine-tuning, Demand Controlled Filtration (DCF), and optimizing airflow pattern. To study the possibilities for fine-tuning and DCF, two case studies were investigated and simulations were performed to assess the potential of both options. Experiments in a demonstration cleanroom were used to examine how an ideal airflow pattern may be achieved in the cleanroom, resulting in a high contaminant removal efficiency. Results showed that DCF could lead to substantial energy savings, up to 93.6% in the specific case study facilities. Besides this, DCF based on occupancy could be implemented with negligible effect on the environmental cleanliness requirements. Fine-tuning, based on particle concentration, required representative measurement of the concentration in the cleanroom. It was more difficult to implement in practice. With respect to contaminant removal efficiency, best results (within the experiments performed, ACR in the range of 16h−1 – 38h−1), were obtained when air was supplied without a diffuser above the product area and when the work position was located close to the air extraction grilles.

Highlights

Compared to an average commercial building, cleanrooms consume much larger amounts of energy [1]–[4]
Energy use reduction of cleanroom ventilation was investigated along the two solution directions discussed above: (A) Air Change Rates (ACRs) optimization based on performance requirements and actual use; (B) Ventilation efficiency improvement through appropriate ventilation design of cleanrooms
Demand Controlled Filtration (DCF) based on occupancy: For case studies H and R, the ACR was controlled based on occupancy

Summary

Introduction

Compared to an average commercial building, cleanrooms consume much larger amounts of energy [1]–[4]. System typically accounts for 50–75% of the cleanroom’s total electrical energy use [5], [6]. This is due to the high air change rates (ACRs) necessary to achieve the required cleanliness classification, as defined in the European Union Good Manufacturing Practice (EU-GMP) [7]. The EU-GMP cleanliness classification refers to maximum allowable particle concentrations in a cleanroom. In order to supply these high ACRs into the cleanroom, supply side requirements are in place. The intention is to provide good mixing throughout the room, leading to a uniformly low particle concentration in the room [8]. Apart from swirl diffusers, other solutions like unidirectional downflow systems are employed

Methods

Results

Discussion

Conclusion