System comprising a display unit (2, 3002) for storing and displaying food products, and multiple shelves, wherein the display unit has a front side and a back side, and comprises multiple walls, including a top wall, a left side wall, a right side wall, a bottom wall, and a back wall, and the display unit further comprises an air circulation system, and a first air refrigerator, in which the top, left side, right side, bottom, and back walls delimit an open front chamber for the food products, such that the open front chamber is accessible from the open front, the multiple shelves each comprise a placing side, the multiple shelves are placeable in the display unit to each extend in the open front chamber in a vertical spaced relationship and to define an individual corresponding storage space above the respective placing side, the air circulation system comprises a lower air duct with a lower front inlet, an upper air duct with an upper front outlet, and a first air forcing apparatus, the first air forcing apparatus is provided for moving air through the lower and upper air ducts, from the lower front inlet towards the upper front outlet, the first air refrigerator is provided for cooling the air which is moved from the lower front inlet towards the upper front outlet, the upper front outlet is directed at the lower front inlet for creating a front air curtain in front of the open front, at least one of the multiple shelves is a hollow shelf (140, 141) with an inner space, a front side and a back side, which front side and back side in use correspond to the front side and the back side of the display unit, the hollow shelf (140, 141) comprises at least one shelf air outlet at the front side of the hollow shelf, at least one shelf air inlet at the back side of the hollow shelf, characterised, in that the hollow shelf (140, 141) further comprises a shelf air forcing apparatus, and a shelf heater, and that the shelf air forcing apparatus is in fluid connection with the shelf air inlet and the shelf air outlet for moving air from the shelf air inlet through the hollow shelf (140, 141) to the shelf air outlet. the top, left side, right side, bottom, and back walls delimit an open front chamber for the food products, such that the open front chamber is accessible from the open front, the multiple shelves each comprise a placing side, the multiple shelves are placeable in the display unit to each extend in the open front chamber in a vertical spaced relationship and to define an individual corresponding storage space above the respective placing side, the air circulation system comprises a lower air duct with a lower front inlet, an upper air duct with an upper front outlet, and a first air forcing apparatus, the first air forcing apparatus is provided for moving air through the lower and upper air ducts, from the lower front inlet towards the upper front outlet, the first air refrigerator is provided for cooling the air which is moved from the lower front inlet towards the upper front outlet, the upper front outlet is directed at the lower front inlet for creating a front air curtain in front of the open front, at least one of the multiple shelves is a hollow shelf (140, 141) with an inner space, a front side and a back side, which front side and back side in use correspond to the front side and the back side of the display unit, the hollow shelf (140, 141) comprises at least one shelf air outlet at the front side of the hollow shelf, at least one shelf air inlet at the back side of the hollow shelf, characterised, in that the hollow shelf (140, 141) further comprises a shelf air forcing apparatus, and a shelf heater, and that the shelf air forcing apparatus is in fluid connection with the shelf air inlet and the shelf air outlet for moving air from the shelf air inlet through the hollow shelf (140, 141) to the shelf air outlet.