www. refrigerationandaircon. co. za RACA Journal I May 2025 13
Events and Exhibitions
To illustrate the efficiency of evaporative cooling, Kotze uses a simple rule of thumb: to generate 700 kW of cooling, evaporating 1 000l of water per hour is sufficient. When compared to conventional air conditioning systems, which rely on compressor-based cooling, evaporative cooling shows a remarkable difference in resource usage.
In a typical compressorbased air conditioning system, an energy efficiency ratio
The commencement of the AERSA CPD course.
( EER) of around 3 means that achieving 700 kW of cooling would require 250 kW of electricity. and humidification processes are separated— do not affect
The energy cost for such a system would be significant, with a indoor humidity levels significantly. In fact, combining indirect much larger environmental impact due to the energy-intensive evaporative cooling with conventional air conditioning can nature of electricity production. optimise energy use and reduce overall electricity consumption.
In contrast, evaporative cooling requires far less electricity due The transition to evaporative cooling presents a compelling to its lower power demand, making it about 90 % more efficient solution for reducing both energy and water consumption in in terms of energy consumption. Water consumption, too, is commercial buildings. By harnessing the natural process of notably lower when compared to conventional air conditioning, evaporation, these systems not only provide energy-efficient which typically requires large quantities of water to generate cooling but also contribute to global sustainability goals. electricity in power plants.
Hakbijl’ s presentation highlights how adopting these innovative technologies can significantly reduce the environmental impact ADDRESSING COMMON MISCONCEPTIONS of cooling systems, save costs, and contribute to meeting While Hakbijl emphasises the numerous benefits of evaporative stringent climate control regulations. cooling, he also acknowledges some common objections. A As the world continues to focus on sustainability, evaporative frequent concern is that evaporative cooling systems consume cooling offers a practical and effective alternative to traditional more water than conventional air conditioners. However, as he air conditioning methods. With its proven energy efficiency and demonstrates, this is not the case. In fact, evaporative cooling water conservation benefits, it is a step forward in the quest for systems consume significantly less water when compared to the more sustainable building operations. RACA water initially used by power plants to generate the electricity that powers conventional air conditioners.
Another objection is that evaporative cooling increases indoor humidity. Hakbijl clarifies that while direct evaporative coolers do increase humidity, indirect systems— where the cooling
All images by © RACA Journal
Essentially, when water evaporates, it absorbs heat, which cools the surrounding air.
A packed house of attendees.
www. refrigerationandaircon. co. za RACA Journal I May 2025 13