Demand response (DR) is one of the energy management strategies that can relieve the strain on power grid by balancing the energy consumption and production. Cold storage in warehouses and cold rooms, due to the high thermal inertia contained in the stored products, is a promising solution for applying DR. For cooling applications, different DR strategies can be considered: stopping evaporator fans or stopping the refrigeration machine, producing more cooling power during off peak hours and reducing the cooling operation during on peak hours, etc. However, these scenarios need to be carefully applied to respect the temperature regulation in order to maintain food quality and security. Moreover, DR application might lead to an increase of power demand when restarting the cold machine - the postponing power effect or an over-consumption of energy for the recovery of the temperature level before DR - the postponing consumption effect. This paper presents an experimental investigation of DR application in a loaded cold room; the impact of several DR parameters: product load, outside temperature, set point temperature and DR duration were assessed. The results showed that DR has limited impact on the stored product: a maximum increase of 1.1 degrees C at the product core after 3 days of DR application, one DR per day. However, a cumulative effect of DR applications on product temperature was observed. The indicators of the postponing power effect and consumption variation showed important impacts of studied parameters on the system behaviour during DR application.