Vortex Tube Cabinet Coolers Sizing Guide

Cooler Sizing         Temperature/Load Conversion Table         Air pressure

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Sketch of Cabinet cooler

Sizing Guide for Cabinet Coolers

For Known Head Load         For Unknown Head Load

To Calculate Heat Load for your Enclosure

Determine the total heat load. This is the combination of two factors, the heat dissipated within the enclosure and heat transfer from the surrounding area.

For known head load in cabinet

1. Convert the know heat load in watt to BTUH ( watt x 3.41 = BTUH)

2. Determine the Temperature difference between the surroundings, at maximum temperature, and the desired internal cabinet temperature.

3. Refer to the Temperature /Load Conversion Table and find the closed temperature differential.

4. Multiply the Value Shown for BTUH/sq. Ft. by the Surface Area ( in Square Feet) of the Cabinet

5. Add the equipment head load in BTUH, to the Surrounding heat Load to determine the Total Heat Load.


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For unknown heat load in cabinet ( watts):

1. Determine the temperature difference between the surroundings at present temperature, and the present internal cabinet temperature.

2. Determine the temperature difference between the surroundings, at maximum temperature, and the present internal cabinet temperature.

3. Determine the difference between the present internal cabinet temperature the desired internal cabinet temperature ( if the desired temperature is lower)

4. Add the temperature difference of steps 1 through 3 to determine the total temperature difference

5. Refer to the Temperature /Load Conversion Table and find the closest temperature differential.

6. Multiply the value shown for BTUH/sq. Ft by the surface area ( in Surface Feet) of the cabinet.



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Temperature/Load Conversion Table
°F 5 10 15 20 25 30 35 40
BTUH/Sq.Ft. 1.5 3.3 5.1 7.1 9.1 11.3 13.8 16.2


To Calculate Heat Load for your Enclosure
For Known Head Load         For Unknown Head Load





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Example
Cabinet Area 50 Square Feet
Maximum Surrounding Temperature (a) 100°F
Present Surrounding Temperature (b) 90°F
Present Cabinet Temperature(c) 100°F
Desired Cabinet Temperature(d) 90°F
Maximum Temperature Difference (a-b) + (c-d) 20°F


The temperature/load Conversion table shows a 20°F temperature difference to a load of 7.1 BTUH per square foot of surface area.

50 (sq. Ft) x 7.1( Factor) = 355 BTUH

Therefore, 400 BTUH Vortex Cooler System is the proper choice.



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Compressed Air Pressure

Vortex Cooler Systems are designed to use normal factory air pressures of 70-100 PSIG ( 4.8-6.9 Bar). Unless Supply pressures are subject to wide fluctuation or are higher than 110 PSIG ( 7.6 Bar) use of a pressure regulator is not requires

Determine capacities of Vortex Cooler systems at pressures less the 100 PSIG ( 6.9 Bar) as follows:

Capacities of Vortex at pressures less than 100 PSIG
Pressure
PSIG   (BAR)		 Percent
Remaining Capacity
90     (6.2) 91
80     (5.5) 83
70     (4.8) 65
60     (4.1) 54

Example: A 400 BTUH Vortex Cooler System, Connected to an 80 PSIG compressed air supply is rated at 332( 400X.83) BTUH. The preceding example would require a 1500 BTUH Vortex Cooler System


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gnt byitfrom.com
April 2000