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VENTS OKF1 400x200-3

  • Description
  • Characteristics
  • Downloads
  • Dimensions
  • Additional diagrams
  • Legend

Direct-expansion duct coolers are designed for cooling of supply air in rectangular ventilation systems and can be used either for supply or supply and exhaust units.


The DX coolers are available in OKF and OKF1 mofications. The OKF1 cooler has a simplified design. The cooler casing is made of galvanized sheet steel, the piping is made of copper tubes and the heat exhange surface is made of aluminium plates. The coolers are available in 3 rows modification and designed for operation with R123, R134а, R152а, R404а, R407с, R410а, R507, R12, R22, R32 cooling agents. It is equipped with a droplet separator and a drain pan for condensate collection and removal.

For OKF and OKF1 models by default the service side is located on the right side from the air stream direction.

The OKF cooler service side location can be changed by coil turning by 180°. The OKF1 modification does not have this option.

  • Mounting is effected by means of flange connection. Direct-expansion cooling coils, can be installed horizontally only to enable the condensate draining.
  • Installation shall be performed in such a way as to provide the uniform air srteam distribution along the entire cross section.
  • The air filter shall be installed at the cooler inlet to ensure the cooler protection against dirt and dusting.
  • The cooler can be installed at the fan inlet or outlet. If the cooler is located at the fan outlet the air duct between the cooler and the fan shall be at least 1-1.5 m long to ensure the air stream stabilization.
  • To attain the maximum cooling capacity the cooler must be connected on counter-flow basis. All the nomographic charts in the catalogue are valid for such connection.
  • The droplet separator is made of polypropylene profile and prevents condensate dripping from the cooling tubes by the cooling air flow. While selecting a cooler type consider that the most suitable speed of the air flow for the efficient droplet separator operation is up to 4 m/s.
  • Condensate draining from the cooler shall be performed through the U-trap. The U-trap height depends on the total pressure in the fan. The trap height can be calculated using the figure and the table below.


H (mm) K (mm) P (Pa)
100 55 600
200 105 1100
260 140 1400



Н - U-trap height

К - drain height

Р - total pressure in the fan

  • To ensure the correct and safe cooler operation use the automation system providing the complex control and automatic regulation of the cooling capacity and air cooling temperature.
Counter flow connection Parallel flow connection

Air pressure losses in freon coolers 

Rectangular OKF1 series

Parameter OKF1 400x200-3
Measurement unit
Rectangular duct size Rectangular duct size 400х200 mm
Casing material galvanized steel -
Width 400 mm
Height 200 mm
Files archieve
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"OKF, OKF1" product description 05-2022 (pdf 3.63Mb)
"OKW, OKW1, OKF, OKF1" user's manual 09-2019 (V63EN-04) (pdf 2.1Mb)
Download high quality image "OKF1" (psd 1.44Mb)
Download image "OKF1" for your website (png 315.73Kb)
VENTS OKF1 400x200-3
Parameter Value Measurement unit
∅D1 12 mm
Ø D2 22 mm
B 400 mm
B1 420 mm
B2 580 mm
H 200 mm
H1 220 mm
H2 270 mm
H3 103 mm
L 44 mm
Additional diagrams
Additional diagrams

How to use freon cooler diagrams:

Air Speed. Starting from 950 m3/h on the air flow scale draw a vertical line 1 till the air speed axis. It makes 3.35 m/s.

  • Supply air temperature. Prolong the line 1 up to the point where it crosses the outside air temperature (e.g. +30°C); then draw a horizontal line 2 from this point to the left till  crossing  the outside air humidity (e.g. 50%). From this point draw a vertical line 3 to the supply air temperature at cooler outlet axis on top of the graphic (+21.1°C).
  • Cooling capacity. Prolong the line 1 up to the point where it crosses the outside air temperature (e.g. +30°C) and draw a horizontal line 4 from this point to the right until it crosses the outside air humidity curve (e.g., 50%), from here draw a vertical line 5 up to the scale representing the cooling capacity (4.7 kW).
  • Cooling agent discharge. Prolong the line 5 down to cooling agent discharge axis at the bottom of the graphic 6 (100 kg/hour).
  • Cooling agent pressure drop. Draw the line 7 from the point where the line 6 crosses the black curve to the pressure drop axis. (6.5 kPa).

Series   Flange designation (WxH) [mm]   Number of cooling coils
  400х200; 500х250; 500х300; 600х300; 600х350; 700х400; 800х500; 900х500; 1000х500   3
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