international journal of mechanical engineering and ... · of air curtain device, it is necessary...

International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –

6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, May - June (2013) © IAEME

79

EXPERIMENTAL PERFORMANCE ANALYSIS OF FLOW OF AIR

CURTAIN

Mr Nitin Kardekar1, Dr. V K Bhojwani

2, Dr Sane N K

3

1Principal, Jayawantrao Sawant Polytechnic.Research Scholar, Singhania University

2Professor JSPM’s Jayawantrao Sawant College of Engineering, Pune

3Research Supervisor, Singhania University

ABSTRACT

A study is undertaken to establish a relation between the power consumed by air

curtain and the performance of air curtain in terms of discharge air velocity from it. The

prototype experimental set up is established in the laboratory. The series of observations are

made by varying the input voltage and its effect on the output air velocity of the air curtain.

The air velocity forms the invisible barrier of air in the form of curtain which separates the

conditioned and unconditioned environments. The results are displayed in the form of graph.

The graphs are analysed in the light of actual performance and conclusions are drawn from

the study. The study reveals that there is great scope of savings in power consumption by

making small changes in the design of air curtain.

Keywords: air curtain, discharge air velocity, performance of air curtain, power consumption

of air curtain, effectiveness of air curtain.

INTRODUCTION

For the study and analysis of the performance of air curtain, the application chosen is

door way air curtain. The door way air curtains are extensively used in shopping malls,

banks, retail shop etc. The purpose is to restrict the cold/hot air loss from conditioned space

by installing the air barrier. An air curtain device also helps in prevention of dust, dirt or

insects entering in to conditioned spaces. Air curtains are also finding applications in

avoiding smoke propagation, biological controls and explosive detection portals. According

to research by US department of energy, 1875MW energy will be saved per year if super

market display cabinet air curtain will be operated at optimised performance [4] In 2002 the

INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING

AND TECHNOLOGY (IJMET)

ISSN 0976 – 6340 (Print)

ISSN 0976 – 6359 (Online)

Volume 4, Issue 3, May - June (2013), pp. 79-84

© IAEME: www.iaeme.com/ijmet.asp Journal Impact Factor (2013): 5.7731 (Calculated by GISI) www.jifactor.com

IJMET

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80

UK food and drinks industry used equivalent of 285 tonnes of oil to power its refrigeration

industry, with most being used in cold storage. In developing countries like India; the rise in

cold storages, super markets, retail stores, banks are not only limited to mega cities but they

have also become the integral part of suburban’s and small towns. The effects of

globalisation are inevitable. The air curtains are no more luxury but are the necessary part of

business development and economy. Hence the study of air curtain with respect to Indian

climate is utmost necessary to ensure optimised performance of air curtains which will lead to

energy conservation. The saving of energy (Electrical energy) will always be boon for energy

starving country like India.

METHODOLOGY

The Technocrat make air curtain for door size W – 950 mm X H – 2530 mm Model 3

ft. HV+ Beta is chosen for the analysis purpose. As shown in Figure 1 the prototype of door

way is manufactured with help of plywood which is supported by MS angle frame. The air

curtain is mounted on the door way. The flow straightener is added in order to reduce the

turbulences in the air flow. In order to reduce direct interference of the suction head of the air

curtain, the suction duct is added as shown in Figure 1. The length of the Suction head is kept

1000 mm from the end of the air curtain device. The power cord of air curtain is connected to

mains through the dimmer stat. Dimmer stat helps in the variation of input voltage to the air

curtain device. The voltage change will change the output of dual motor (i.e. speed of the

shaft). This results in variations of output air velocity of air curtain device. The air velocity in

air curtains is a very important parameter impacting its effectiveness. The input voltage to fan

motor is measured by digital multi meter. The power supplied to air curtain is measured by

the watt meter. In order to measure the air velocity at fixed points, a grid of the thread is

placed in air flow path of air curtain. This facilitates to measure the velocity of air flow of air

curtain when input parameters are varied. With help of grid it is easy to find the location of

point in the space for measurement of velocity at different input voltages. The input voltage is

varied from 125 V to 225 V with increment of 25 Volts. The speed of the fan is measured

using digital Tachometer and the velocity is measured using digital anemometer. All the

instruments are calibrated before use. The entire experimentation is carried out at isothermal

conditions; ambient air at 240C ( + 1

0C) at one atmosphere.

RESULT AND DISCUSSION

The prototype experimental set up is established in the laboratory. The series of

experimentation is carried out in the laboratory. In the observation, the input voltage thereby

power to air curtain is varied and its effect on discharge air velocity of air curtain is observed.

The voltage is varied in the steps of 25V with the help of dimmer stat. The speed of the

centrifugal fan of the air curtain is measured with tachometer. The discharge air velocity is

measured with the help of turbine type anemometer in m/s. The observations and results are

presented graphically. Figure 2 shows the graph of Input voltage verses the power input to air

curtain. Figure 3 shows the graph of Input voltage verses speed of the centrifugal fan of air

curtain motor. Figure 4 shows the graph of Input voltage verses discharge air velocity of the

air curtain. From figure 2 it is clear that, as input voltage is increased, the input power also

increases. At 125V input the input power observed is 50 watts where as at input voltage 225

V it increases to 100 watts. At input of 175 V the input power recorded is 70 watts and at

International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976

6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, May

input voltage of 200 V the input power is 90 watts.

air curtain is increased the power consumed by the motor is also found increasing. Figure 3

shows the graph of input voltage verses the

input voltage increases the fan speed is also increase

the fan speed is 822 rpm. It reaches to 1432 rpm

volts fan speed stabilises even for i

voltages of 200 V and 225 V the fan speed is 1460 rpm and 1468 rpm respectively.

even though there are increments of 25 V and 50V

are only 28 rpm and 36 rpm. The graph of output

velocity of 3.3 m/s and 5.2 m/s is measured at input voltage of 125V and 150 V. It increases

to 9.2 m/s at input voltage 175 V. A marginal increment of 0.4 m/s and 0.6 m/s is observed

for the further increment in the input voltage of 25 V and 50 V respectively. Thus output

velocity stabilises beyond 175 V.

velocity of the air curtain reveals all these details

should run the air curtain near optimum voltage to

can be used, without affecting the performance of air curtain

form barrier of moving air to separate the two environments.

out of the air curtain device decides the quality of barrier. Higher the velocity, more robust is

the air curtain barrier. From abo

the discharge air velocity when it is operated at 175 V, 200 V and 225 V. Thus we can say

that equally strong air curtain can be obtained when

voltage of 175 V. The further

substantial improvement in the discharge

Figure 1

International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976

6359(Online) Volume 4, Issue 3, May - June (2013) © IAEME

81

nput voltage of 200 V the input power is 90 watts. Thus as input voltage to fan motor of the


graph of input voltage verses the speed of the centrifugal fan. It is observed that

the fan speed is also increases initially. For the input voltage of 125 V

the fan speed is 822 rpm. It reaches to 1432 rpm for the input voltage of 175 V. Beyond 175

stabilises even for increased input power to air curtain device.

V and 225 V the fan speed is 1460 rpm and 1468 rpm respectively.

though there are increments of 25 V and 50V in input voltage, the fan speed increments

The graph of output air velocity also shows similar nature. The



for the further increment in the input voltage of 25 V and 50 V respectively. Thus output

175 V. Figure 4 is the graph of input voltage verses the output air

reveals all these details. It is clear from above discussion

should run the air curtain near optimum voltage to save the power else the lower power motor

be used, without affecting the performance of air curtain. The air curtains are provided to

form barrier of moving air to separate the two environments. The velocity of the air coming

decides the quality of barrier. Higher the velocity, more robust is

the air curtain barrier. From above discussion it is clear that there is not much difference in

air velocity when it is operated at 175 V, 200 V and 225 V. Thus we can say

that equally strong air curtain can be obtained when the device is operated even at

f 175 V. The further increase in input of power will merely be waste

discharge air velocity.

Figure 1: Photo of the Experimental set up


June (2013) © IAEME

Thus as input voltage to fan motor of the


It is observed that, as

initially. For the input voltage of 125 V

for the input voltage of 175 V. Beyond 175

For the input

V and 225 V the fan speed is 1460 rpm and 1468 rpm respectively. Thus

the fan speed increments

shows similar nature. The



for the further increment in the input voltage of 25 V and 50 V respectively. Thus output air

is the graph of input voltage verses the output air

from above discussion that one

save the power else the lower power motor

The air curtains are provided to

The velocity of the air coming

decides the quality of barrier. Higher the velocity, more robust is

ve discussion it is clear that there is not much difference in

air velocity when it is operated at 175 V, 200 V and 225 V. Thus we can say

evice is operated even at the input

waste without



82

Figure 2: Input Voltage Vs Power

Figure 3: Input Voltage Vs Fan Speed



83

Figure 4: Input Voltage Vs air Velocity.

The optimum voltage there by optimum performance for this model is found to be at

175 V. During experimentation it was observed that the power required by the air curtain

device increases with increase in voltage. The power required at 175 V is 80 watts. At 200 V

and 225 V power consumed is 90 watt (12.5% more) and 100 watt (25% more) respectively.

But there is hardly any improvement observed in terms of air velocity (2% and 4%

respectively). Hence it is recommended to use lower capacity motor without affecting the

performance of the air curtain device. As discussed earlier the air curtain devices are

extensively used across the globe to protect the conditioned environment. The millions of air

curtain are functioning at the malls, banks, commercial places, cold storages etc. If air

curtains devices are shifted to use lower capacity motors at optimised conditions as discussed

in the paper without affecting their performance then the huge electrical power will be saved.

Using lower power consumption motor for air curtain applications will certainly reduce the

demand of the electricity in larger extents for these commercial spaces.

CONCLUSION

The output of the air curtain device is measured in terms of velocity of air. The input

power is varied and efforts are made to optimise the performance of the air curtain device. It

is concluded that instead of adopting the generalised approach for designing and installation

of air curtain device, it is necessary to design the air curtain device considering the particular

application. This will ensure the use of the lower capacity and lower power consumption

motor for air curtain devices for a given application. Considering the extensive use of the air

curtain devices in the entire world the demand of the electricity will be certainly reduce in the

larger extents. And thus millions of dollar will be saved in energy bills globally.

0

2

4

6

8

10

12

100 125 150 175 200 225 250

Ma

xim

um

ve

loci

ty in

m/s

Input voltage to fan motor

Input voltage vs discharge air velocity



84

REFERENCES

[1] Tassou, S. A. and Pappas T. C., ‘Numerical Investigations into the Performance of

Doorway Vertical Air Curtains in Air-Conditioned Spaces’, ASHRAE Transactions,

Vol. 109, No. 1, 2003, pp. 273–279.

[2] Y. T, Ge, and S A Tassou,’Simulation of the performance of single jet air curtain for

vertical display cabinets’, Applied Thermal Engineering, Vol. 21,2001 pp.201-219.

[3] Field B. & Loth, E., ‘Entrainment of refrigerated air curtains down a wall’,

Experimental Thermal and Fluid Science, 30, 2006, pp. 175-184,.

[4] Dr. Homayun K. Nawaz, Dr. Dana Dabiri Mazyar Amin and Ramin Faramarzi ‘Past,

Present and future Research towards air curtain performance optimisation’, OR-05-

16-4.

[5] Hampl, V., Johnston, O. E. and Murdock, D. J., Jr, ‘Application of an Air Curtain-

Exhaust System at a Milling Process,’ American Industrial Hygiene Association

Journal, Vol. 49, No. 4, 1988, pp. 167–175.

[6] Etkin, B. and McKinney, W. D., ‘An Air-Curtain Fume Cabinet’, American

Industrial Hygiene Association Journal, Vol. 53, No. 10, 1992 pp. 625–631

[7] A. Aubert and C. Solliec, ‘Push-Pull Air Curtain Performances for VOCs

Containment in an Vol 4, No.1 2011, pp.43-50, (ISSN 1735-3645)

[8] Mr Nitin Kardekar and Dr Sane N K, ‘Effect of humanoid shaped obstacle on the

velocity profiles of flow of air curtain’ International Journal of Mechanical

Engineering and Technology, Volume 3, Issue 3, 2012, pp. 511-516, ISSN Print:

0976 – 6340, ISSN Online: 0976 – 6359

[9] Kapil Chopra, Dinesh Jain, Tushar Chandana and Anil Sharma, “Evaluation of

Existing Cooling Systems for Reducing Cooling Power Consumption”, International

Journal of Mechanical Engineering & Technology (IJMET), Volume 3, Issue 2, 2012,

pp. 210 - 216, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359.

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