Which cooling system is best

Water is sprayed over plastic cooling tower fill, which creates a large surface for water to evaporate. A fan moves air through the tower to induce evaporation which in turn cools the water. Cooling tower systems are typically the least expensive of the three types of systems to operate; however, the maintenance requirements for filtration and water treatment is the highest of the three. Chiller systems are used in applications where neither a fluid cooler nor cooling tower system can get cool enough to meet the requirements for the process.

In a chiller, refrigerant is used to pull heat from the process fluid and transfer it to ambient air or cooling tower water. Of the three types of cooling systems, chiller systems are the most expensive to purchase and operate.

Chillers require some form of cooling to their condensers, which is where the refrigerant gas that was boiled using the process heat is condensed back to a liquid. The three types of chiller condensers are shown below. With the above basics you will be able to choose which type of cooling system you should consider to cool your process.

Once that is known it is best to work with a manufacturer who specializes in that type of process cooling equipment. Also, it now requires some secondary coolant during warmer times of the year. Both the trim cooler and the air cooled fluid cooler will require periodic maintenance and cleaning. The next system, an open-loop evaporative cooling system is completely different than the first three listed above. This system has the ability to use the design wet bulb as the basis for the outlet temperature of the cooling water.

For example if the design dry bulb for the location is 95 F and the design wet bulb is 75 F, the system can provide approximately 82 F water to the load. The open-loop evaporative cooling system cascades water through the honeycomb PVC fill material in the tower along with ambient air blown or drawn through the fill to evaporate the water.

During the evaporation, the remaining water is cooled to as close as 7 F or higher above the wet bulb temperature. The evaporated water is replaced with some type of make-up water system like a float valve. The remaining water and the make-up water are collected in a basin and then pumped to the load and the cycle repeats. The advantage of this system is that the equipment is typically inexpensive. The systems can be simple to employ in warmer climates but may require more controls in colder climates.

The weaknesses of this type of system are that they normally require an extensive water treatment system. The water treatment system uses expendable chemicals to keep the calcium and dissolved minerals in suspension.

The chemical treatment is necessary to ensure that the cooling tower, piping, and heat exchangers do not become fouled. An inherent issue with the open tower evaporative system is that the water that flows through the tower is also the heat transfer fluid that is pumped through the load. This water comes in contact with the dirty atmosphere. It picks up pollutants such as dust, vegetation, etc.

These contaminates end up in the heat exchangers and piping and can cause significant maintenance issues. Open towers can have control issues in the winter months. They are designed to run at full load. They do not always perform well under part-loading in very cold climates. If the basin is part of the tower, a heater is required for cold weather operation to keep the basin water from freezing when the load is not present.

The piping will normally require insulation and heat trace in cold climates to prevent freezing. A drain will be required for blow-down of the water to keep the conductivity in check from the constant evaporating and concentrating of the dissolved solids.

Make-up water is continually required from external source such as city water or treated well water, etc. Biological control of bacteria, slime, and mold are major concerns for proper operation of an open evaporative tower system. A closed-loop evaporative system is a hybrid system.

The closed loop evaporative system is an open tower with a closed-loop heat exchanger built into the tower. The tower water stays outside in the tower and does not circulate through the coolant piping. The separate tower water is pumped from the basin to the top of the tower and sprays across the heat exchanger normally an array of tubes with air blown or drawn through the tower across the heat exchanger where evaporation of the water transfers the heat from the closed coolant loop to the ambient air.

The remaining tower water falls to the basin where it is again pumped up to the top of the tower and repeats the process. The closed-loop evaporative system tower water requires make-up water, chemical treatment, a drain, cold weather basin heater, and blow-down just like the open-loop evaporative system discussed above. The advantage of the closed-loop evaporative system is that it can deliver closed loop coolant to the load at approximately 7 to 10 F above the wet bulb temperature.

The closed-loop coolant remains free of contaminates and allows the equipment heat exchanger and piping to remain clean. Any contaminates from the atmosphere will stay outside with the tower. Fewer water treatment chemicals will be used because they are only treating the open water in the tower and not the coolant in the piping and system heat exchangers. The exhaust heat of the processor is integrated into this circuit and transported to the radiator.

Here, the heat that has previously been cooled down through the water is distributed to the surrounding air. As with air cooling, an active and a passive option exist with water cooling systems.

With passive systems, the cooling process at the radiator happens through standard air movement. With the active option, a fan is responsible for producing the air stream. Prior to choosing a cooling system, a few factors should be considered. In general, you should bear in mind that water cooling systems only ever cool down certain areas of the computer. Thus, a water cooling solution does not replace the default cooling system for other, built-in components of the computer.

Moreover, a water cooling system may take additional effort during the installation process. This is the case when the main board has to be removed in order to install the cooler, for example. Modern cooling systems that are designed as tower coolers offer an increased cooling performance, thanks to heat pipes. If you only have limited space for a cooler due to a compact design, low profile cooling systems are a good option.

Measurements are specifically designed for HTPCs or narrow cases. With a CPU cooler, pay attention to compatibility between components of different manufacturers or different technologies. If the cooling system is based on AMD technology, it is often not compatible with Intel bases. The same is also true vice versa. This is, however, not an issue with the majority of water cooling systems. Most water coolers are compatible with both AMD and Intel. If you choose a purely CPU ventilator, look out for the noise level in the product specifications to avoid a noisy, distracting system.

Besides choosing an appropriate cooling system, computer overheating can be prevented by following a few simple rules of thumb. For example, there should be a minimum distance of 50cm between the computer case and nearby walls and furniture, to allow the heat to escape. Ventilators and coolers should never be hidden behind objects. Heat sources such as lamps and should not be placed in immediate proximity to the computer.