Solution:                       Evaporative Cooling System

Client:                           Henkel Loctite Limited

 

The Client was recording excessively high internal temperatures of 42°C in its lead powder production area during the summer months. This was caused by excessive heat loads generated by several lead furnaces on a mezzanine floor heating the surrounding air, which in turn was being trapped inside the building. The problems caused by the high temperatures were two-fold: employee productivity remained low and absenteeism high, and product quality was affected as the process requires low temperatures for efficient atomisation.

 

MECHON were commissioned to design project manage combined heat extraction and evaporative cooling system to reduce internal temperatures to acceptable levels and help overcome these issues.

A series of six roof-mounted extract fans were installed above the process equipment on the mezzanine floor. These were evenly spaced to provide for equal extraction of the warm air as it radiated upwards from the process equipment. To compliment this, an evaporative cooling system was installed to supply cooled air to the production area through a series of grilles, mounted within a system of high level ductwork, spanning all areas within the facility.

The evaporation of water requires the taking of latent energy (heat) from the ambient atmosphere. The result of this is that the incoming ambient air decreases in temperature. External air is drawn in and across a series of mats in the unit, which are kept wet by a constant supply of water. A stainless steel sump at the base of the unit is kept full by a valve and the water is re-circulated through the mats using a pump and distribution system. As the water passes over the mats, a proportion is evaporated into the air stream thus reducing its temperature.

An integrated electrical panel was installed to control the main functions of the evaporative cooling unit. A selection switch on the front of the panel allows the unit to be operated in either ventilation only or cooling modes. A thermostat was also connected to control the fan and water pump independently. This enables high and low temperature and humidity settings to be dictated. Running costs are significantly reduced as the system only operates when above the external set-point temperature. When external temperatures are below the set-point the system either provides mechanical ventilation with no water usage or shuts down completely.

 

Since installing this system, temperatures within the area have not exceeded 28°C, which has resulted in consistent product quality and increased productivity due to improved working conditions for employees.