Case Study – Cooled Concrete Ceiling

Heat transfer model

Surface mesh

Temperature in the concrete

The challenge

A design consultancy is proposing an air-conditioning system for a new office block in which cooled concrete ceilings will supply part of the cooling requirements for the offices below. The consultancy must show that the ceilings will provide 45 W/m² of cooling when the room temperature is 24°C and 55 W/m² of cooling when the room temperature is 26°C.

The concrete ceilings will contain rows of hollow plastic spheres to save weight. The spheres will complicate the flow of heat into the ceilings, so the cooling cannot be calculated based on the simple assumption of one-dimensional heat flow into the top and bottom surfaces of the ceiling.

The solution

Atkinson Science created a three-dimensional heat transfer model of a cooled concrete ceiling using ANSYS fluid flow and heat transfer software.

The model gave the temperature distribution in the ceiling and the average heat flux over its top and bottom surfaces. The computations demonstrated that the required amount of cooling would be achieved.

The benefits

With expert assistance from Atkinson Science, the design consultants were able to make a convincing case for using cooled concrete ceilings as part of the air-conditioning system of the office block.