Heat Exchanger Pre-Cooling Systems

Heat exchanger pre-cooling consists of cooling the air flowing to the heat exchangers to improve their performance on a hot day. MeeFog systems atomize water to create a fog of liquid water droplets that evaporate and cool the air.

On a hot afternoon, our pre-cooling helps heat exchangers cool down by 30°F (17°C) or more in an arid climate, at least 20°F (11°C) in a temperate climate, and at least 10°F (5.6°C) in a tropical climate.

Indirect evaporative cooling allows the condenser to release heat more effectively, which makes the chiller more effective on a hot day.

MeeFog pre-cooling systems can be designed to provide several stages of cooling. For instance, a system capable of 10 °F of cooling can be designed with two indirect evaporative cooling stages of 5 °F each. This allows you to do only as much cooling as is needed, thereby conserving water usage.

MeeFog controls fog droplet sizes using precision high-pressure nozzles. Small, uniform droplets stay suspended in the air, supporting effective indirect evaporative cooling. Small droplets matter because they expose more water surface to air.

Faster evaporation cools the air more efficiently and reduces water loss. Larger droplets drip off the heat exchanger before evaporating, wasting water and lowering cooling performance. Smaller droplets save water and improve overall cooling efficiency.

Yes. MeeFog systems can be easily retrofitted to existing air-cooled heat exchangers.

The water should have low levels of calcium and magnesium since these minerals can form a hard scale that is difficult to remove from the heat exchanger fins. Mee Industries can help design a water treatment system that will provide long life and minimal maintenance.

MeeFog pre-cooling systems can operate automatically based on ambient temperature. For example, in a two-stage setup, the first stage turns on above 85°F (30°C), and the second stage turns on above 90°F (32°C). You can adjust set-points using climate data or process needs. Some systems also control based on the cooled fluid temperature leaving the heat exchanger, optimizing indirect evaporative cooling even further.

MeeFog pre-cooling systems need minimal maintenance. Inlet water filters should be replaced periodically, and any water treatment equipment needs routine service. The high-pressure pumps are water-lubricated, multi-stage centrifugal units designed to run for many years with little maintenance.

A MeeFog pre-cooler for heat exchangers can operate for more than 30 years with proper maintenance. The fog nozzles themselves do not wear out and can be used for the life of the system, assuming water treatment is maintained.

MeeFog systems reduce water fallout by using many fog nozzles with low flow rates that prevent over-wetting of coils. Any overspray that occurs can boost indirect evaporative cooling, as water evaporates from the hot coil surfaces, improving overall heat rejection and system efficiency.

Fog nozzles, fog nozzle lines, feedlines, and pumps are all stainless steel, which provides long life and requires minimal maintenance.

To install a pre-cooling system for heat exchangers, typical lead times are about 12 weeks for smaller projects and up to 24 weeks for larger ones. MeeFog pump skids arrive fully assembled, with fog nozzles installed and factory-tested.

Nozzle lines usually ship in 20-foot sections. Installation involves bolting the pump skid to a foundation, then connecting the feedlines and nozzle lines. MeeFog supplies all required drawings and a technical advisor to support the installation process.

Yes, we’ve documented several indirect evaporative cooling projects showing measurable performance gains on steam condensers, AC condensers, and other systems. 

MeeFog pre-cooling systems can be used whenever the temperature is above freezing. It is usually possible to cool by at least 10°F (5.5°C) even on humid afternoons in a tropical climate.

We guarantee the amount of cooling a system will produce on a hot day. MeeFog systems have a 12-month warranty. Longer warranty terms are available on request.