FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
DEVICE AND METHOD FOR REDUCING SURFACE CONDENSATION
BLUE STAR LIMITED, A COMPANY INCORPORATED UNDER COMPANIES ACT 1956, WHOSE ADDRESS IS KASTURI BUILDINGS, MOHAN T. ADVANI CHOWK, JAMSHETJI TATA ROAD, MUMBAI- 400 020 MAHARASTRA, INDIA;
THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF THE INVENTION
The present invention relates to a cold fluid handling device like Air handling Units, refrigeration systems etc. and particularly to a device and a method for reducing surface condensation over the cold fluid handling devices. BACKGROUND OF THE INVENTION
Cold fluid handling units including Air handling units (AHU's) face the problem of condensation over the outer surface especially, those AHU's that are functional in places where the ambient humidity is high. Usually condensation takes place on an outer surface where the temperature of the outer surface is lower than the dew-point temperature for a given ambient temperature and relative humidity (RH%). Generally, condensation on the outer surfaces of air-conditioning and refrigeration systems is observed at the sites where relative humidity is high. Generally, condensation takes place mostly at external metallic surfaces. Once the temperature of the outer surface lowers to dew point, condensation will commence.
The condensation can lead to meager air quality, create a wet and slippery floor around the enclosure due to water dripping. In some cases, freezing of the condensate and accumulation of frost is observed causing a poor appearance

and preventing doors or other moving parts of the enclosure from operating. Further, condensate causes oxidation, followed by corrosion on the affected surface, the condensation on the outer surface of the AHU is bad. If the AHU room remains wet constantly it can lead to growth of fungus which is unhygienic. In view of the above there is a need in the art for a device and a method that can reduce surface condensation.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide a method and a device that reduces surface condensation over the cold fluid handling device. Accordingly, the present invention in an embodiment provides a device for reducing condensation over an outer surface of a cold fluid handling device, comprising a means for increasing atleast minimal surface area of the outer surface of cold fluid handling units required for increasing heat exchange with ambient air so as to raise temperature of the outer surface substantially higher than the dew point temperature so as to reduce the surface condensation. Jn another embodiment, the present invention provides a method for reducing condensation over an outer surface of a cold fluid handling device, comprising steps of: increasing atleast minimal surface area of the outer surface of cold fluid handling units required for increasing heat exchange with ambient air for raising surface temperature substantially higher than dew point temperature.

According to further embodiment of the present invention, a coating can be applied over the surface of the device of the present invention to increase radiation heat absorptivity of the said device.
DESCRIPTION OF THE DRAWINGS:
The preferred embodiment of the present invention will now be described with reference to the accompanying drawings, which are given by way of example and are not to be taken as limiting in any way. The accompanying drawings are intended to make the invention easier to understand.
Figure 1 shows a perspective view of a typical Air handling unit;
Figure 2 shows a device of the present invention;
Figure 3 shows a perspective view of a preferred embodiment of a device of the
present invention along with air handling unit shown in Figure 1;
Figure 4 shows an alternate embodiment of a device of the present invention;
and
Fig. 5 shows the comparison of heat exchange of the air handling unit as shown
in Fig. 4 without and with a device of the present invention with the help of CFD
simulation.
DESCRIPTION OF THE INVENTION
The present invention provides a device and a method for reducing condensation
over an outer surface of a cold fluid handling device.

The present invention takes advantage of heat transfer. It is generally accepted that there are three basic mechanism of heat exchange: conduction, convection and radiation. Usually condensation takes place on a surface when the temperature of surface is lower than the dew-point temperature for a given ambient temperature and relative humidity (RH%). To reduce condensation, it is required to have the outer surface of the cold fluid handling device above either the dew point temperature or at ambient temperature. If the surface temperature is raised to a temperature higher than the dew point temperature by exchanging heat with the ambient air, no condensation will be observed. To bring out the outer surface temperature above the dew point, the heat transfer between the outer surface of the cold fluid handling unit and air is increased. Accordingly, a means is provided to increase the heat transfer between the outer surface of the cold fluid handling unit and air which increases the outer surface area of the cold fluid handling units so as to maximize the contact between the ambient air and the surface in order to take maximum heat transfer between the ambient air and outer surface of cold fluid handling device irrespective of cold fluid temperature in the cold fluid handling unit. Due to the maximum heat transfer between the outer surface and the ambient air, the temperature of the outer surface raises above the dew point. Further, the amount of heat exchanged can be increased by increasing the velocity of ambient air and would need and additional fan or

adequate ventilation. Further, the amount of heat absorbed by radiation can be increased by increasing the absorptivity, which means increasing the capacity of the AHU corner to absorb more radiation from the ambient air. In general, the present invention provides a device for reducing surface condensation comprising a means for increasing atleast minimal surface area of outer surface of the cold fluid handling units required for increasing heat exchange with ambient air so as to raise temperature of the outer surface higher than the dew point temperature. The cold fluid handling units can be air handling units, refrigeration units or the like,
The present invention also provides a method for reducing surface condensation comprising steps of: increasing surface area of the outer surface of cold fluid handling units for raising outer surface temperature higher than dew point temperature by exchanging heat with ambient air.
As per another embodiment of the present invention, the surface area of the outer surface of cold fluid handling units can be increased preferably by adapting fins on the outer surface of the cold fluid handling units. According to the present invention the fins can be adapted removably. Alternatively, the fins can be adapted rigidly that is in-built with the cold fluid handling units.

According to the present invention, a coating can be applied over the surface of
the device of the present invention to increase absorptivity of the said device.
The coating paint known in the art can be used for increasing absorptivity.
According to the present invention, the surface area required to be increased is
calculated based on the ambient temperature, maximum humidity attained at the
site, outer surface temperature of the air handling unit and the temperature of the
cold fluid.
Now, referring to the drawings, by way of example to the structure of the device
to reduce surface condensation over an Air Handling Unit (AHU) of the present
invention.
Figure 1 shows a typical air handling unit (10) use for transferring cold air from
one place to another place.
Referring Figure 2 shows a preferred embodiment of the removably adaptable
device (100) for reducing surface condensation according to the present
invention.
As shown in Figure 2, the device (100) includes elongated plates (120) and a
plurality of fins (130) adapted to the plate for increasing the surface area of the
Air handling unit as shown in Figure 1.

The device (100) can be manufactured based on the shape of the Air handling
unit. Figure 4 also shows a different shape device (200) which is manufactured
based on the shape of the Air Handling Unit (20).
The device provides an increased minimum surface area required for raising
outer surface temperature higher than dew point temperature by exchanging heat
with ambient air.
Figure 3 illustrates the device (100) of the present invention shown in Figure 2
adapted over the air handling device (10) shown in Figure 2. The device can be
adapted over the air handling units removably by various known ways of fittings
for example screwing, snap fitting etc. Alternatively, the device can be
permanently fixed over the outer surface of cold fluid handling units by spot
welding, soldering etc. Alternatively, the air handling device can be manufactured
with increased surface area that is inbuilt air handling units.
The material of the device can be similar that of the cold fluid handling device
aluminum, copper, steel or any heat conducting material.
Fig. 5 shows the comparison results of CFD (Computational fluid dynamics)
simulation between the AHU with and without the device for reducing surface
condensation over the AHU. It can be observed from Fig. 5 (a) and Fig. 5 (b) that
the proposed design has higher area weighted average surface temperature than
the current design. The temperatures from CFD analysis form the basis our

conclusion that the present invention will allow condensation free operations at
higher RH than current.
The device of the present invention can be fitted over the outer surface of the
existing AHU. The present invention reduces condensation on AHU surfaces at
high humidity sites.
While the invention has been described with respect to presently preferred
embodiment, it will be understood that the invention can be applied to numerous
forms of applications. Accordingly, the principles of the invention are not limited
to the embodiment described. The invention is capable of certain modification
and change without departing from the spirit of the invention.

We Claim:
1. A device for reducing condensation over an outer surface of a cold fluid handling device comprising:
a means for increasing atleast minimal surface area of the outer surface of cold fluid handling units required for increasing heat exchange with ambient air so as to raise temperature of the outer surface substantially higher than the dew point temperature so as to reduce the surface condensation,
2. The device as claimed in claim 1, wherein the device can be coated to increase radiation heat absorptivity to enhance the absorptivity of the increased surface.
3. The device as claimed in claim 1, wherein the surface area can be increased by adapting fins on the outer surface of the cold fluid handling units.
4. The device as claimed in claim 3, wherein the fins can be adapted removably or rigidly.

5. The device as claimed in claim 1, wherein the means of the device can include a frame with atleast one elongated plate and a plurality of fins adapted to the strip for increasing the surface area to enable heat exchange.
6. The device as claimed in claim 1, wherein the material of the device can be aluminum, copper, steel, or any heat conducting material.
7. The device as claimed in claim 1, wherein the device has higher area weighted average surface temperature than a cold fluid handling unit without such a device.
8. The device as claimed in claim 1, wherein the cold fluid handling units can be air handling units, refrigeration units or the like.
9. A method for reducing condensation over an outer surface of a cold fluid handling device comprising steps of:
increasing atleast minimal surface area of the outer surface of cold fluid handling units required for increasing heat exchange with ambient air

for raising surface temperature substantially higher than dew point temperature.
10. The method as claimed in claim 10 further comprising step of coating the increased surface area for enhancing absorptivity of the surface.