Double Stage Air Washer

Air washer machine is utilizing the natural process of water evaporation along with an air moving system to create effective cooling. The ambient air is pulled through filters and it passes through the cooling pad then it cools the air through water evaporation. A blower circulates the cooled air throughout a suitable ducting and grill network arrangements.

Advantages of Air Washer

Low installation cost, Low running/operation cost.
Effective in high heat generation areas.
Easy & inexpensive maintenance.
Healthier System - Since it works on 100% fresh air.

Technical Explanation of Double Stage Air Washer

In the single stage Air-washer humidity level rise to that level that makes occupants uncomfortable because 6ltr. of water evaporates to give us the cooling effect of 1tr. Double stage Air-washer do not produce humidity level as high as that produced by single Air-washer.
In the first stage of a two stage Air-washer, warm Air is pre-cooled indirectly adding humidity by passing the warm Air through the heat exchange that is cooled by passing cold water which is pre cooled by the evaporation process.
The pre cooled Air then passed through a water soaked cellulose pad where it picks up the humidity as it cools. Since the air supply is pre cooled in the first stage so the less humidity is transferred in the second stage to reach the desired cooling temperatures.
The result is cooled air with a relative humidity between 55%-70% while single stage Air-washer produces above 75-85% of RH.

Psychometric Chart

Comparision With Conventional Air Conditioning

S. No.	Double Stage Evaporative Air Cooling	Refrigerated Air Cooling
1	Uses only 25% of the electricity compared with conventional air conditioning.	Power consumption is very high.
2	As temperature rises efficiency improves.	As temperature rises efficiency reduces.
3	Cooling capacity is only limited by the air conditions. Up to 15KW of cooling can be achieved with only 1 KW of electricity used.	Cooling is limited by theoretical Coefficient of Performance which means a maximum of 3.5 KW of cooling for 1 KW of electricity consumed.
4	Open doors and windows do not affect performance.	Open doors and windows significantly reduces performance.
5	Uses no harmful gases for its function.	Uses environmentally harmful gases.
6	Avoiding relative humidity below 50% significantly reduces static electricity problems	Leads to low relative humidity which can create high static electricity conditions.
7	In dry weather better cooling effect can be achieved.	In dry weather efficiency of the Air Conditions reduced so high power consumption.
8	Easy and simple to service.	More difficult and expensive to service.
9	Always supplies 100% fresh air.	Only supplies about 15% fresh air. 85% is re-circulated. It is not fresh.
10	Air only cooled once.	Air cooled many times.
11	Has no upper limit on temperature. No tapping problem during the high temperature period.	High ambient temperatures can lead equipment to shut down due to compressor overload
12	Lower purchase cost.	Higher cost to purchase.
13	Have bigger fans - pump large amounts of air.	Smaller fans - pump less air.
14	Temperature reduction limited by ambient web bulb temperature not by dry bulb temperature.	At higher Relative Humidities cooling is reduced due to greater latent heat load compared to sensible load.
15	Provides stable relative humidity levels which are more comfortable to work in	Can lead to low Relative Humidity which is not comfortable.
16	Simple to create positive pressure in buildings giving hygiene and control benefits	More difficult to create positive pressure with recirculation systems.

Double Stage Air Washer