The Effect of Supply and Outdoor Air Temperature on The Enthalpy and Temperature Exchange Efficiency of a Paper Heat Exchanger

Teoh Zhi Heng,Chin Wai Meng,Abudulkareem Sh Mahdi Al-Obaidi,Kenny James Ling Neng Hui,K.S Chun,N Zaman,P.S King,C.H Leng,F.W.Y Myan

doi:10.1051/matecconf/202133503015

Abstract

Heat Recovery Ventilator (VHR) is widely used nowadays as it is capable to maintain high Indoor Air Quality (IAQ) while minimizing the energy loss of indoor air through air-to-air heat exchanger principle. The main component that enables VHR to perform air-to-air heat exchange is known as Paper Heat Exchanger (PP-HEX). Hence, the objective of this research is to study and analyse the performance of a PP-HEX under different return and outdoor air temperatures as well as their effect on both enthalpy and temperature exchange efficiency. Moreover, some numerical models of VHR have been developed to optimize some complex cases and the numerical models are meant to reduce the physical experiments to analyze or improve complex cases in the future. To the best of the authors knowledge, there is no experimental data available from any sources to validate the numerical models. To address this issue, two different supplies of PP-HEX are tested with an actual VHR, and both PP-HEXs will be referred to as PP-HEX-A and PP-HEX-B due to confidentiality. Furthermore, the testing is conducted in a temperature-controlled testing laboratory and the testing conditions are set according to the ISO standard. The preliminary testing results show that the temperature exchange efficiency and enthalpy exchange efficiency of the PP-HEXs have the same trends while the outdoor air temperature is fixed and varying the temperature of indoor air. In contrary, the temperature exchange efficiency and enthalpy exchange efficiency of the PP-HEXs have the same trends while the indoor air temperature is fixed and varying the temperature of outdoor air as well. With the default voltage supplies (240V) to VHR and the setup conditions (according to the ISO Standard) of return air to be 27°C and outdoor air to be 35°C, the testing results show that PP-HEX-A has a temperature exchange efficiency and enthalpy exchange efficiency with a range of (37.97 – 40.28) % and (30.77 – 57.81) % respectively. While PP-HEX-B has a temperature exchange efficiency and enthalpy exchange efficiency with a range of (35.29 – 42.5) % and (39.6 – 55.93) % respectively.

Highlights

The Heating, Ventilation and Air-Conditioning (HVAC) system is an integrated system that provides environmental comfort to the human activity spaces and maintains the high level of Indoor Air Quality (IAQ)
The raw data, enthalpy, temperature exchange efficiency and enthalpy exchange efficiency of the first testing scenario of both Paper Heat Exchanger (PP-HEX) are tabulated as shown in Tables 1, 2 and 3 respectively
There are several important parameters to be considered in the future optimization study to minimize the errors in results

Summary

Introduction

The Heating, Ventilation and Air-Conditioning (HVAC) system is an integrated system that provides environmental comfort to the human activity spaces and maintains the high level of Indoor Air Quality (IAQ). As part of HVAC, the ventilation system plays an important role as it can affect the human’s health and comfort. The enclosed space could be contaminated with toxins or viruses and affect human health or even cause people to fall sick. The ventilation system is improvised to provide a better IAQ by replenishing fresh air and removing the carbon dioxide and contaminated air (odours, bacteria, dust etc.) [1]. IAQ plays an important role which would tremendously affect human’s health

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Conclusion