High-rise buildings.

How does the airflow of high-bay refrigerated warehouses work?

Thermal comfort and climate control of high-rise buildings: EOLIOS brings its technical expertise to the understanding and modelling of thermo-aeraulic exchanges.

Why study the airflow of high-bay warehouses?

High-bay refrigerated warehouses are a type of warehouse equipped with a cooling system to maintain constant, appropriate temperatures for the stored products. This type of warehouse is often used to store temperature-sensitive products, such as foodstuffs, medicines and pharmaceutical products.

The cooling system can be sized for a standalone cold room or as a system integrated into the warehouse itself. High-bay refrigerated warehouses are designed to allow large quantities of products to be stored safely and without altering their quality or freshness.

Thermal stratification, a recurring problem in warehouses

Thermal stratification is a common problem in high-bay warehouses. This physical phenomenon occurs when air layers at different temperatures separate and do not mix, creating zones of uneven temperature at different levels of the warehouse. This can lead to poor temperature distribution, making it hard to maintain a uniform temperature and potentially causing the loss of stored products.

Thermal stratification also makes it harder to optimize the energy efficiency of climate-control systems, creating additional costs for companies. It is therefore important to work to minimize thermal stratification in high-bay warehouses using strategies such as installing ventilation units, designing an optimal cooling system and controlling warm-air inflows.

Cold rooms of pharmaceutical laboratories

These high-bay warehouses often hold tens or hundreds of millions in goods. To ensure product quality, temperature-monitoring systems in the pharmaceutical industry are very strict. Temperature deviations can make entire batches obsolete and cause considerable economic damage.

Because of the geometric nature of this type of premises, with heights sometimes above 20 metres, vertical temperature differences can develop if the ventilation and air-conditioning technology does not take adequate countermeasures. For cooling in summer as for heating in winter, this creates difficulties regarding the type and positioning of the ventilation technology, as well as the sizing and type of heating and cooling. The blockage of airflows by the shelving and stored goods can adversely affect air circulation, resulting in hot or cold zones in summer or winter.

In this context, safeguarding the temperature requirement for all outdoor climate conditions and all operating situations is of great importance. Flow simulation, in conjunction with thermal building simulation, is an important instrument to support planning.

Why use CFD for high-bay zones?

CFD simulation makes it possible to predict the thermal and climatic conditions, including air circulation and temperature distribution, inside high-bay zones, whether existing or at the design stage.

This can help to understand potential problem zones and identify them so that measures can be taken to correct them quickly and at lower cost. CFD simulation also makes it possible to assess the effectiveness of the cooling and air-conditioning systems in high-bay zones and to determine whether adjustments are needed to maintain appropriate conditions for the stored products.

Finally, CFD simulation can be used to assess the potential consequences of adding new equipment in high-bay zones, such as when setting up redundancy systems. Systems placed too close together can interfere with each other, and by-pass effects or dead zones can then appear. To assess the potential consequences of the changes made — such as temperature and humidity — CFD simulation is the most suitable tool to minimize the risks to your products.

Is installing redundancy systems necessary?

What is system redundancy?

In thermal engineering, the term "system redundancy" means the duplication of systems in order to ensure that, when one or more systems fail, the others in place can compensate for the lost capacity.

As explained earlier, controlling the climate conditions is a decisive point in order to guarantee the compliance of the stored products and avoid any loss of goods. However, putting such systems in place is not necessarily easy: it is sometimes difficult to install new systems without one system disturbing another.

Why use CFD to size your redundancy?

Using CFD simulation to size the redundancy of your systems offers many advantages. First, it makes it possible to test the different redundancy scenarios without taking real risks with the existing system. This helps identify the best redundancy strategies in terms of reliability, cost and performance. CFD simulation also makes it possible to predict the system's performance under real conditions, which can be difficult to do without a computer model. Finally, it helps to avoid costly errors in the system design by providing precise data on the expected performance.