Reports a new control strategy developed for cooled ceiling panels. This makes it possible to use the cooled ceiling panels not only during working hours when an internal load is present, but also at night, when it is possible to use the thermal mass of the building for energy storage. Notes that night cooling also helps to reduce the peak load during working hours. It makes it possible to produce part of the cold water at lower outside temperatures and when the costs of electricity are lower. Presents example calculations of the effect of night cooling using a simulation program.KEYWORDS: year 1995, Controls, ceiling cooling, panel cooling, nighttime cooling, calculating, energy storage, electricity consumption, off peak electricity