Which type of cooling tower is more efficient? This is a question many heating and cooling specialists have asked themselves, and the answer isn’t always a straightforward one. Cooling towers are an integral part of most commercial and industrial cooling systems, from industrial and commercial air conditioning units to even other types of heat recovery systems. No matter how often your facility uses its internal cooling tower, keeping it running efficiently and safely is an extremely important aspect of routine communication tower repair.
Different Type of Cooling Towers
Most modern air conditioners use a combination of different types of cooling towers. The most popular type of towers are:
- Positive displacement or positive-edges.
- Positive static, also known as static compression.
- Crossflow cooling towers.
While each has its unique style, they all use one common factor: cool air is vented from the tower through a small gap in the casing and then into the air inside the room or building. The gap provides a low-pressure area for the warm air to be pulled into while preventing cool air from escaping and warming up the surrounding area.
Positive-edges cooling towers use a special liquid-cooling solution that is heated on the outside of the tower. As the liquid cools, it leaves the tower and fills the gap left by the evaporated refrigerant. As the process continues, it draws in more warm air and continues the cooling process. Over time, this results in a gradual cooling of the surface area of the tower, with the result being lower energy bills.
Static compression cooling towers function in much the same way. They don’t employ a fluid cooling solution like the static compression units. Instead, they use a liquid to dampen the evaporation process. Instead of letting the liquid escape, it continues the cooling process by slowly drawing in cooler water through the nozzles. Again, over time, this results in a lowering of the water flow temperature through the machinery. The machinery may also have to be occasionally repaired or maintained depending on the type of machinery and its location.
Non-ice filling cooling towers can be used in many different applications. Some examples include filling puddles and cracks in equipment. They work by using a refrigerant to fill a cavity, which provides a source of cold water to stop the evaporation process and keep the equipment from overheating. This type of cooling tower requires regular maintenance because a buildup of ice can occur if the refrigerant used is not cold enough. Ice builds up between the gaps between the nozzles, which makes the process inefficient. It’s important to periodically check and refill the reservoir to prevent damage to the equipment.
Warm-up blow-down towers are known for their efficiency in summer climates. These towers use a pump to draw hot air through a cooling system. As the hot air passes through the system, evaporation occurs, with some of the warm air being sucked into the evaporator coils. The rest of the cool air is directed away from the tower and into the evaporator coils, where it becomes cold before it ever reaches the inside of the tower.
All type of cooling towers has one problem common to all – evaporation. To prevent water loss or reduce the amount of water loss, one must select the right sort of unit. It’s better to have a system that draws water from a higher altitude and spreads the heat out, rather than a lower altitude pump that draws air from high-pressure areas and spreads it out. The problem is that air temperatures change quickly from high-pressure areas to low-pressure areas. A lower altitude pump may have a higher efficiency rating per square foot, but it will also draw air from areas with evaporation problems. The problem will become evident, though, when buildings use them.
An alternative to the warm-up and downdraft systems is a natural draft cooling tower. A natural draft tower functions differently – rather than blowing hot air up and blowing cool air out, this system allows air to enter and exit the tower at different temperatures. However, a natural draft tower needs a lot of space – it can be as large as a small house and requires a concrete foundation and careful construction. This type of cooling tower can only operate during certain seasons and can’t be moved around easily.