Published: Thursday, 09 Feb 2017
Author: Ali Hussain
Department: Global Center for Food Systems Innovation
While hunger plagues a quarter of India's 1.3 billion people, food losses continue to stack up, rotting and wilting during post-harvest and processing. To improve on-farm food storage and divert food waste, a team of researchers funded the Global Center for Food Systems Innovation are implementing two types of evaporative cooling (EC) technology.
Led by Sangeeta Chopra, of the Indian Agricultural Research Institute (IARI), and Randy Beaudry, of the Department of Horticulture at Michigan State University, the team has constructed four EC structures on the IARI campus in New Delhi. Designed to stand alone or be retrofitted with a refrigeration system to improve cooling, the storage structures keep food cool through two types of evaporative cooling technology.
The first – high porosity bricks – enhances evaporation and cooling potential, similar to how a clay pitcher keeps water cool in hot environments. The second runs on a solar-powered refrigeration unit, keeping electricity costs low and making it more practical for farmers to use. The solar-powered unit also provides a renewable energy source for activities in village communities.
Explaining the science behind the cooling technology, Chopra said, "The walls of the structure are wetted at a controlled rate to achieve maximum evaporative cooling. The design and material for the roof and floor have also been finalized for lowest heat transfer."
Aimed at increasing the capabilities of smallholder farmers in India, the team is comparing the performance of different materials used in the storage container walls, which include pervious concrete, traditional brick-sand-brick layering, and mesh-supported fabric. The results of the tests are used to validate mathematical models that predict performance.
Discussing preliminary results, Chopra said, "A fabric-covered mesh structure with low thermal mass and high thermal transmittance outperforms other designs, cooling faster and obtaining lower temperatures. (It) also cost significantly less to build, and was easier to construct than brick- or concrete-based designs."
Back in the States, the team has partnered with Turbo Ventures to develop a specialized solar-powered refrigeration compressor at Michigan State University.
With advanced cooling technology and improved refrigeration capacity, low carbon footprint storage containers decrease food waste and lead to a more food secure future. Even if just one-fourth of the food lost globally were saved, it would feed 870 million hungry mouths.