From eSociety, April 2018
Radiant cooling systems can use less energy at a lower installed cost, but the systems’ performance can depend on the climate they are working in.
In an article for the April edition of Science and Technology for the Built Environment, Mahabir Bhandari, Member ASHRAE; Jyotirmay Mathur, Member ASHRAE; and Yasin Khan analyze the operation of the cooling system in different climates. The research, “Energy–Saving Potential of a Radiant Cooling System in Different Climate Zones of India,” can help engineers design and decide operational parameters for a particular climate.
1. What is the significance of this research?
This research details the energy performance of radiant cooling systems in different climatic conditions of India. The results are based on a carefully developed calibrated simulation model of an existing building with a radiant cooling system. Additionally, the research goes one step further and describes the need and procedure of component level calibration, which can play a very important role for comparing HVAC systems based on the real building operation and measurement.
2. Why is it important to explore this topic now?
Radiant cooling systems are demonstrated to be more energy efficient than all–air systems, and their use is increasing, especially in India.
A technical feature that compared VAV and radiant systems side–by–side for an IT building in Hyderabad, India, and presented the findings in ASHRAE Journal (May 2014 issue) concluded that radiant systems used 34% less energy at a lower installed cost. The real building measured savings encourages other building and facility owners to adopt radiant systems.
However, the performance of radiant cooling systems varies significantly with the weather conditions, especially for the humid weather conditions. Therefore, a detailed systematic study is required to estimate the performance of radiant cooling systems; and thus, the importance of exploring this topic now.
3. What lessons, facts, and/or guidance can an engineer working in the field take away from this research?
This article provides the analysis of the operation of the radiant cooling system for different climates, which can be helpful for the engineer in designing and making decisions for operational parameters for a particular climate.
For example, the radiant system may not work standalone in certain climatic conditions. The article also provides the applicability of energy recovery ventilation integrated with the radiant cooling system. This shows that in a climate like Bengaluru there are no benefits of installing ERV. The engineers can make decisions about the selection of systems used for meeting the ventilation and latent load requirements.
This article also provides the energy consumption breakdown for different HVAC components. This might help the engineer to make the decision on the component selection.
4. Were there any surprises or unforeseen challenges for you when preparing this research?
The most challenging thing about this article is the data collection and interaction with the building owner or HVAC plant manager. For component–level calibration, the data requirement is huge. Additionally, to compare the performance radiant cooling system, it is necessary to have the conventional system installed with the same operating condition as the radiant cooling system. This allows for apples–to–apples comparison.
5. How can this research further the industry's knowledge on this topic?
This research will help the industry in the deployment of radiant cooling systems and encourage better market penetration of radiant cooling systems.