IDECool 4

CORE TECHNOLOGY

Indirect evaporative cooling works on the same principle as direct evaporative cooling lowering air temperature by water Evaporation. The major difference in  an indirect system is that it uses an heat exchanger  to cool the air supplied to the working space. The evaporative cooling cycle occurs in the humidification section.

How a  an indirect evaporative cooling system works is explained sequentially:

1. In one type of  System ,Hot outside air is blown over a heat exchanger through which cold water is supplied . This type of heat exchanger features a series of metal tubes through which cold water is supplied and hot air blown over the tubes and fins. As hot air passes over these tubes, its sensible heat is removed. After passing over the tubes, the cool ,dry is delivered to living space.It not only lowers down dry bulb temperature but wet bulb temperature as well.Indirect Evaporative cooler find application where low humid but 100% fresh air is needed for cooling.
2. The another important point is that the hot  air is cooled  without gaining any extra humidity.

Indirect evaporative cooling provides cool air to interior spaces with less  Relative humidity compared to  direct evaporative cooling. This, cooling method is more suitable for areas where additional humidity is not  desirable . Since  indirect evaporative cooling requires two pumps rather than one, it consumes little more electricity than direct evaporative cooling.

In second type of  Indirect Evaporative Cooling system -primary  warm air flows in enclosed channels .It gives up its heat to water films flowing down the other side of the polymeric plates. A secondary air stream flowing in the direction opposite to the water evaporates water before it is exhausted outside. Thus, in Indirect Evaporative cooler the primary air is cooled without any moisture addition .

Advantages of Indirect Evaporative cooling

• Indirect Evaporative coolers delivers 5 Deg.C more Cooling and adds 60% less moisture than DEC.
• Indirect Evaporative Cooling requires 30-40% less air .
• A Make in India Product
• Indirect Evaporative Cooler require 40-60 percent lower energy consumption as compared to conventional air conditioning systems
• 100 percent fresh, clean, cool air
• Indirect Evaporative cooling Creates more comfortable conditions for employees and processes
• Main advantage of indirect Evaporative cooling  is that it do not use any  harmful gaseous .
• Lower supply air temperatures with much lower addition of moisture to the supply air as compared to air washers
• Increased productivity of employees
• Excellent Indoor Air Quality (IAQ) and no Sick Building Syndrome (SBS)

OVERVIEW

Payback Period

Direct evaporative cooling (Single Stage Cooling)

Indirect evaporative cooling

What is direct Evaporative Cooling?

With direct evaporative cooling, outside air is blown through a Honeycomb cooling pad  and cooled by evaporation process. This  cooled air is circulated by a blower ,further.

Direct evaporative cooler  reduces the dry bulb temperature* but   the wet bulb temperature** stays the same. However,it adds moisture to the air .

*dry bulb: Sensible air temperature (as measured by a Thermometer).
**wet bulb: The lowest air temperature achievable by evaporative Air Cooilng System.

What is Indirect  Evaporative Cooling ?

In Indirect evaporative cooling Hot Air and water travel in different channels .They do not come directly in contact with each other, hence the name Indirect Evaporative Cooling.

In Indirect Evaporative  Cooling stage, warm primary air cools by losing its heat to a thin water film on the other side of a conducting surface. And another air stream called Secondary or Scavenging air moves upward through the falling water and evaporates this water.It converts most of the sensible heat into latent heat  before it is exhausted to the outside. Thus ,the primary air is cooled without coming in contact with the water stream. Hence, IEC reduces the dry bulb temperature, wet-bulb temperature, and the enthalpy of the primary air without adding any moisture to it. Moreover ,Indirect Evaporative cooling  are more effective and energy efficient.

Indirect-direct evaporative cooling ( Two Stage Cooling )

In Indirect Evaporative cooling, the primary air is cooled without coming in contact with water. Hence in first stage air is cooled without adding any moisture to it. It is cooled further in the second stage with the direct evaporative cooling process .It ,however, in extra drop of 5 Degree c in temperature

What Temperature reduction is achievable using indirect Evaporative Cooling and direct evaporative cooling ?

First, calculate the dry bulb and wet bulb temperatures achievable with indirect evaporative cooling:
1. Temp drop achievable = (dry bulb – wet bulb ) x (efficiency of indirect module)
Example: (42 degrees C- 23.5degrees C) x .7 = 13 degreesC.

2. Achievable temp = dry bulb – temp drop achievable
Example: 42 degrees – 13 degrees = 29 degrees DB/19.5 degrees WB.

3. Starting DB: 42 degrees
Ending DB: 29 degrees

Then use the dry bulb/wet bulb values from step 3 to calculate the dry bulb/wet bulb temperatures achievable with direct evaporative cooling:
4. Temp drop achievable: (dry bulb – wet bulb ) x (efficiency of the media)
Example: (29 degrees – 19.5 degrees) x .9 = 8.6 degreesC.

5. Achievable temp = dry bulb – temp drop achievable
Example: 29 degrees – 8.6 degrees = 20.4 degrees DB/19.5 degrees WB.

6. Total temperature reduction using indirect/direct evaporative cooling:
Starting DB: 42 degrees C
Ending DB: 20.4 degrees C