Maintaining the right temperatures and hygienic environments in buildings where food production takes place is of the utmost importance. In bakeries, using the right climate control solution can also affect the quality of the final product greatly. Common climate control problems that bakeries face are:
- Dough drying out too quickly in the dry, hot air of the summer months.
- Baked bread taking too long to cool down properly because of ineffective ventilation systems and hot, dry air. This eventually leads to production losses as bread goes stale.
- Uncomfortably warm working conditions for the bakery staff, as the ovens add to the overall temperature in the summer. Loose flour dust particles can also be an irritant and cause extra clean-up duties.
How evaporative cooling solves these common problems:
The advantages of direct adiabatic evaporative cooling in bakeries lie in the humidification of the supply air, without presenting any hygiene risks. By humidifying the air, the dough is protected from drying out and the bread is also given the ideal environment to get a better crust when baking. In addition, the dehydration of the bread when it is cooling is reduced, meaning less waste.
As well as being extremely effective at cooling down the working areas, the moist air also binds flour dust, stopping it from floating around freely and settling everywhere – this results in better working conditions.
To achieve these same benefits, the only other option would be to humidify the air with high pressure or pneumatic atomiser systems. However, it is precisely here where there is a danger of Legionella spreading in the tiny water droplets, unless expensive precautionary measures are taken.
One example of how a Colt evaporative cooling solution has helped a bakery is at “Bacu” in Holland. The conditions in the bakery were stiflingly hot and both staff and bread quality were suffering as a result. Speaking of the problem, Operations Director, Thijs Aldenhuijsen says:
‘On days when it is 30 degrees outside, the temperature in the bakery can sometimes reach 40 degrees. We want to be an employer that takes good care of its employees, so an effective solution was needed.’
Colt was contacted and carried out a survey of the bakery and confirmed the staff observations. They also noted that the bakery was operating at a net under-pressure, due to the mechanical ventilation systems at the ovens. The under-pressure meant that the pressure in the bakery was lower than the pressure outside, meaning the heat stayed inside the building and did not flow out.
To take care of both the under-pressure and the overheating, Colt specified an evaporative cooling solution. Three Colt CoolStream systems were installed on the roof of the bakery to supply cooled air to the building. The supplied air cools down as a result of the evaporation of the water. This cool air is then supplied to three production areas in the bakery, keeping working conditions at the ideal levels.
The adiabatic cooling from the Colt Coolstream units has the potential to supply air up to 10 degrees cooler than the outside air. The cooling system also supplies fresh, oxygen-rich air and removes the under-pressure problem. At lower outside temperatures, such as in winter, the cold outside air is mixed with air in the bakery to get to the right internal temperature, and even in these conditions the ventilation system solves the under-pressure issue. A significant added benefit of adiabatic cooling is that it is many times more energy efficient than traditional air conditioning systems with humification. Moreover, mechanical cooling recirculates indoor air, so little fresh air is supplied. Operational Director Thijs says there are other benefits as well: “Product quality will also benefit from the new cooling method. The more variables in the production process you can control, the more consistent the quality - and that remains a challenge with a natural product such as bread. We can now better control the variables in the indoor climate and the machines we use also have a longer service life at lower temperatures. Plus, less dirt will deposit on machines, which means we will have less maintenance issues. "