Forced Draft Cooling Tower

Forced draft cooling tower installations are becoming increasingly more popular.  Cooling tower technology allows for a fan to be mounted on the top or bottom of a cooling tower.  Cooling towers with top mounted fans are called “induced draft” cooling towers and cooling towers with bottom mounted fans are called “forced draft” cooling towers. 

 

Forced Draft Cooling Tower

Forced Draft Cooling Tower

 

Induced draft cooling towers frequently employ a fan, coupling, gear box, drive shaft and motor at the top of the cooling tower.  This equipment is used to induce air from the bottom air inlet louvers up through the fill media.  This location accelerates wear and tear of the equipment because it is exposed to the elements (sun, rain, snow, etc.), and is positioned in the hot, corrosive exhaust airstream.  This makes the mechanical equipment difficult, expensive, time-intensive and dangerous to maintain. 

Forced draft cooling towers have the mechanical equipment at the bottom of the tower.  This location allows the equipment to operate in the cool, dry intake airstream protected from the elements.  This location makes the equipment accessible from ground level so it is easy, inexpensive, less time consuming and much safer to repair while enjoying substantially increased life expectancy of the mechanical equipment.

Cooling Tower Legionella

Cooling tower Legionella is an ever increasing concern, especially in many HVAC scenarios such as hospital cooling towers, university cooling towers, and other like applications where the cooling tower exists among a large population. There are six events that must ensue in order for a Legionellosis case to occur: (1) An environmental reservoir must exist; (2) multiplication to high cell counts must occur; (3) there must be a mechanism to disseminate bacteria; (4) the disseminated strain must be virulent; (5) infection must occur at susceptible site on a host; and (6) the host must be susceptible.

Being reservoirs of water and dust, all cooling towers can potentially harbor Legionella sp. bacteria thereby satisfying event (1). Events (4) through (6) are beyond the control of cooling tower manufacturers and operators. Thus we have events (2) and (3) in which to exert a protective influence. The environmentally friendly and operator friendly design of the Tower Tech Modular Cooling Tower™, especially when combined with a judiciously administered and monitored biocidal treatment regimen, effectively addresses events (2) and (3).

Learn more about how to avoid cooling tower Legionella by visiting our white paper: http://www.towertechinc.com/documents/Legionella_Control_White_Paper_05072004.pdf

FRP Cooling Tower Structures

FRP cooling tower structures have become increasingly more popular over the past 20 years. Historically, galvanized metal for small to mid-sized applications and wood for mid to large-sized applications had the dominant role in cooling tower structures. Due to environmental, aesthetic, dependability and life expectancy concerns, many users have turned to alternate materials of cooling tower construction such as FRP.

FRP Cooling Tower

FRP Cooling Tower

Galvanized metal and wood structures have posed serious environmental concerns due to the harmful chemicals that can leech out into the cooling tower blow down. The corrosive nature of the materials can become unsightly, require maintenance and repair, and result in reduced life expectancy of the cooling tower.

FRP cooling tower structures are not corrosive and therefore improve environmental friendliness and aesthetics while significantly improving life expectancy with little to no maintenance required. FRP cooling towers include hand laid up, injection molded and pultruded methods of construction. Hand laid up is less popular due to the difficulty of getting consistent fiber distribution, which can result in fiber bloom and degradation concerns. Injection molded FRP is popular for keeping a low price with smaller HVAC applications. Pultruded FRP is the material of choice for mid and large size applications due to the structural integrity of the structure.

Most pultruded FPR cooling towers will have an initial investment 30% greater than that of galvanized metal or wood. However, the benefits to the environment, lack of required maintenance, improved aesthetics and dependability, and significantly improved life expectancy offer a solid ROI.

Rental Cooling Tower

Rental cooling tower options began appearing in the 1980’s with portable cooling towers and then modular cooling towers in the 1990’s. Today there is a booming rental cooling tower industry worldwide. Some companies choose a rental cooling tower because the need for additional cool water is not permanent and they are able to fund the project from their operational budget instead of capital budget.

Today many power plants are faced with increased pressure to preserve minimum water temperatures from the lake or river they use for cool water due to environmental impact of the water life. During the hot summer months these return water temperature restrictions can significantly reduce the amount of energy a plant can produce. A rental cooling tower helps the power plant to keep the water temperature below the required level so they can operate at full capacity all summer long. Other users of cooling towers can also benefit from augmented cool water during the summer months to positively impact their process.

Rental Cooling Tower

Rental Cooling Tower

Other applications of rental cooling towers are to ensure your HVAC or industrial process facility has the cool water it needs during a retrofit, repair or replacement of an existing cooling tower. Since a cooling tower operates much like the radiator on a car, when there is no cool water, there is no process. A rental cooling tower can truly save millions of dollars in lost revenue from a plant shut down.

Whether you are facing temporary incremental heat load, a cooling tower retrofit, planned maintenance, or even an emergency shut down, being familiar with what rental cooling tower options exist can be a life saver in the event of an emergency.