An analysis of the innovative exhaust air energy recovery heat exchanger

Abstract

Heating, ventilation and air conditioning systems are responsible for a nearly 50% of total energy consumption in operated buildings. One of the most important parts of the ventilation system is an air handling unit with a heat exchanger for energy recovery which is responsible for effective and efficient energy recovery from exhaust air. Typically heat exchangers are characterised by the producers by heat and humidity recovery efficiency up to 90% and 75% respectively. But these very high values are usually evaluated under laboratory conditions without taking into account a dynamic change of outdoor and indoor air conditions significantly affecting the recovery efficiency. In this paper, results of thermal, humidity and enthalpy recover efficiency of innovative energy recovery exchanger have been presented. The analysed system allows adjustment of the humidity recovery especially useful in the winter period and forefends energy use for an anti-froze system of energy exchanger. Presented result show that analysed innovative system can achieve the value of thermal efficiency recovery higher than 90% and efficiency of humidity recovery about 80%. This is possible because the analysed system is able to work without the use of any primary source energy or other anti-freeze systems. Presented in this research unique solution is able to work without external anti-freeze systems even in extremely adverse outdoor air conditions such as minus 20°C and humidity 100% RH.

Temperature efficiency of heat exchangers in air handling units

“…This expression refers only to the heat exchanger and not takes into account the energy used by the fans [17][18].…”

Comparison of aerodynamic characteristics for various slot diffusers

“…Heat loss due to ventilation is responsible for about 25-55% total heat loss. Taking into account this fact it has been found [7] that it is hardly possible to obtain primary class energy-efficient building without adequately designed mechanical ventilation system [8].…”

Analysis of heat exchanger in an air handling unit – A case study

“…The highest recorded results during the measurements were 88.6% for temperature ratio, 92.9% for humidity ratio, and 77.1% for total recovery ratio. An analysis of a heat exchanger efficiency in laboratory conditions was also the subject of research in the work of Borowski et al [7]. Measurements of temperature, humidity, and air volume flow rates were carried out.…”