Roy (1984) reported that a 6 tonne cool chamber was constructed, where the side wall was constructed with two layers of bricks leaving approx. 7.5 cm gap in between them. This gap was filled with riverbed sand. The floor was made of wooden planks. Below the floor, a 33 cm deep tank was constructed with 4 air ducts made of bricks opening at the centre and submerged under wet sand. The sand in the wall and surrounding the ducts were saturated with a drip system. The top of the chamber was insulated and incorporated with an exhaust fan. The air while passing through saturated duct and walls cooled sufficiently and took away heat from the produce.
Chouksey (1985) reported the design aspects of a solarcum-wind aspirator ventilated evaporative cooling structureof 20-ton capacity for potatoes and other semi perishables, which was constructed at the Central Potato Research Station (CPRS), Jalandhar. The structure maintained a temperature of 21–25 °C with 80–90% RH at ventilation rate of 24m3/min when the outside temperature and RH were 40–42 °C and 30–35%, respectively.
Anonymous and Roy (1985) and Khurdiya reported the detailed method of construction of a Zero energy cool chamber. A chamber for storage of about 100 kg horticultural produce was constructed with two layers of bricks as side walls leaving approx. 7.5 cm gap in between them. This gap was filled with riverbed sand. The top of the storage space was covered with khaskhas/gunny cloth in a bamboo-framed structure. There was no provision for mechanical ventilation. The sidewall and top cover were kept completely wet during the period of storage. It was observed that the cool chamber had a temperature of less than 28 °C during summer, when the maximum outside temperature was 44 °C. The average minimum temperature of the cool chamber was either less than or near the outside average minimum temperature, excepting in winter, when it maintained a few degrees centigrade more than the outside average minimum temperature.