Austrian Made Low Line Oil to Air Cooler 12 or 24 Volt DC.

This small flow cooler is a high-quality unit capable of cooling an oil flow of 20-30 Lt per minute.
It has 3/4" BSP female ports, to allow easy connection on your oil return line.

Size. 180mm High, 229mm Wide, 115mm Deep
There is an option for a Temperature 'cut in' switch. This is useful for cold climates, so the cooling fan only starts running when the oil heats to either 60°c or 90°.

Machines that need an oil cooler are generally those that are required to operate outside the parameters that they were originally designed for.

For example
A. An internal combustion engine is modified to produce more power.
B. A Transmission Required to Transfer more Torque and Power
C. Racing Applications or Extended High Duty cycles where high power is applied for extended periods of time.
D. A machine designed for operation and use in Northern Europe or North America but sent to operate in hot humid and or tropical environments.

All Oil is designed and formulated to operate effectively within a certain minimum and maximum temperature range. If you operate a piece of equipment for extended periods of time at high loads excess heat is generated and the oil's temperature will rise. If the oil's maximum designed temperature range is exceeded you will experience problems.

For Design assistance and sizing
Please contact us by email at sales@mhfgc.com.au
or phone us on +61 (07) 5563 1982

BUT FIRST !!
Please have the following details, information, and measurements ready
m = Weight or mass of the oil in reservoir [kg] (see below for how to calculate this)
c = specific heat capacity [Wh/kg°C] (for hydraulic oil this is c ~ 0.53 and for water it is c ~ 1.16 )t1 = oil temperature at the begin [in °C]
t2 = oil temperature at the end [in °C]
T = heat up time [hours]
also desirable is the following
Pump or System Oil flow in Litres / minute = L/min
Altitude above sea level (at machine's location) = in m
Desired oil temperature at inlet = in °C
Maximum expected cooling air inlet temperature = in°C


To read more about problems you can expect to encounter, (look for more blue font below the following oil cooler calculations.)
How to Calculate the Size of an Oil / Air Cooler.

You will need a thermometer (infrared is best) to measure oil temperature and a timepiece to measure the time. Pick a location on the machine where heat is experienced and you know oil is flowing through it and measure at the same location every 15 minutes, recording the temperature and the time.
Summarise all recordings
Start temperature
The rise or final temperature
And the time it took (in hours) for the temperature to rise to the final recording.


The theory
When there is power transfer, friction, or resistance to oil flow, pressure, as well as heat, are generated. The temperature of oil in a circuit will continue to increase until the added thermal energy has the same value as the combined radiation and convection energy absorbed by the surrounding atmosphere.

After a certain operating time, the oil temperature rise will eventually slow and then stabilize.
If this stabilized oil temperature is too high, the oil must be cooled because Hot Oil will Cost you repairs, a lost job, or a lost race!
In order to choose the required cooler type we must know the required cooling performance.

How to find out the required Oil cooling requirement.
Example A. With the rise in Oil Temperature
For existing Hydraulic / Oil circuits the heat input to the oil can be accurately determined if the rise in the Oil's temperature is measured over a certain period of time. This then gives the amount of heat to be exchanged by the cooler in order to maintain the system at an optimum operating temperature.
PK = m x c x (t2 – t1) / 1000 x T
PK = required cooling performance [kW]
m = Weight or mass of the oil in reservoir [kg] (see below for how to calculate this)
c = specific heat capacity [Wh/kg°C]
(c ~ 0.53 for hydraulic oil, c ~1.16 for water)
t1 = oil temperature at the beginning [in °C]
t2 = oil temperature at the end [in °C]
T = heat up time [hours]

To Quickly Calculate the Oil weight or Mass (in Kilo Grams) of the hydraulic oil in a tank use the following formula.
Length x Width x Height of tank in cm then multiply by 0.00088
For Example, If a hydraulic tank on an 8-ton excavator was 40 cm long, 30 cm wide, and 60 cm high then 40 x 30 x 60 = 72000 cm³
72000 x 0.00088 = 63.36 KG

For the Volume of Cylindrical Tanks
measure the diameter D and length or height H in cm and then use the following Formula
V= πD²H/4

Eg Worked example for the excavator's tank dimensions above.
PK = required cooling performance [kW]
m = Weight or mass of the oil in reservoir [kg] 63.36
c = specific heat capacity [Wh/kg°C] 0.53
t1 = oil temperature at the begin [in °C] 25
t2 = oil temperature at the end [in °C] 113
T = heat up time [hours] 45 minutes = 45/60 = 0.75 hours
PK = m x c x (t2 – t1) / 1000 x T
PK = 63.36 x 0.53 x (113-25) / 1000 x 0.75
PK = 33.58 x (88) = 2955 / 750
PK = 3.94 KW

After calculating the required cooling performance (PK ), the specific cooling performance (Pspec) must be determined.
Selection of the cooler
Cooler selection can only be carried out once the specific cooling performance (Pspec) in kW/°C is calculated.
P spec = PK / (T oil – TL)
P spec = specific cooling performance in (kW/°C)
PK = required cooling performance [kW]
T oil = oil temperature inlet (°C) (desired temperature)
T L = air temperature inlet (°C) (maximum expected temperature)
P spec = 3.94 / (60-40)
P spec = 3.94 / 20
P spec = 0.197 kW/°C

Using the ASA Hydraulik website's calculator and entering the following information a range of suitable oil coolers will be displayed.
Pump or System Oil flow in Liters / minute = 40 L/min
Altitude above sea level = 50 m
Desired oil temperature at inlet = 60°C
Maximum cooling air inlet temperature = 40°C
as well as (below)

What happens when oil is too hot
1. Shorter Oil Life
Hydraulic Oils or Transmission Oils operating at temperatures above 65°C (150°F) will start to deteriorate at an accelerated rate, which will result in shorter oil change periods. For Example, having to change your Hydraulic System's oil every 1000 hours instead of 1500 hours or your transmission oil every 15,000 KM instead of 30,000 KM. Result in more money is spent on Oil and filters.

2 Gasket and Seal Damage
Hot Oil damages Gaskets and Seals and this may result in Internal as well as External Leaks.

3. Internal Leaks
Internal leaks reduce efficiencies, power, and or torque of hydraulic cylinders, pumps, and motors and in the case of transmissions may cause erratic performance, slow acceleration, and or gear shifting.

4. External leaks
External Leaks can make a mess of your mobile equipment as leaks are blown all over the underside of your vehicle, dust and grime will then stick to the oily components creating an ugly sticky mess requiring cleaning

5. Dangerous Slip Hazards
Oil leaking or dripping onto a non-absorbent floor or road not only makes a mess but also creates a potentially dangerous slip hazard that may result in an automotive accident with personal and property damage and possible prosecution.

6. Fines for Environment damage and Pollution
Oil Leaks onto the ground could be interpreted as contamination and pollution and you risk being fined. The actual or perceived risk of environmental impact from an oil leak is real, so stop that leak or at the least clean it up and save yourself the potential of legal action and a fine or imprisonment!

A recent Client of ours was sent a clean-up bill for AU$3,500 when their excavator was left unattended and unchecked over the weekend leaking hydraulic oil into the ground on a particularly sensitive government construction site.

7. Mechanical Damage
Large external leaks if left unchecked will reduce or deplete the oil level of the hydraulic oil circuit causing excess friction and even more heat generation, poor performance, and eventually catastrophic mechanical damage.

8. Poor Efficiency
Lastly, the Hydraulic system's efficiency is reduced because the oil viscosity changes (usually gets thinner), and more power losses are experienced resulting in even more heat being generated with reduced machine performance and or productivity.
If on the hand you operate a piece of equipment UNDER the oil's designed temperature range you risk the following problems.

9. Poor Oil Flow when oil is too cold.
An oil that is designed to operate at 10°C to 40°C ambient temperatures will be too thick to flow
properly a -5°C, This can cause the machine's oil pump to cavitate which causes accelerated mechanical wear and contamination in the oil.

10. Insufficient Lubrication
When a pump cavitates it is not actually pumping as much oil volume as it was designed to do and therefore not enough oil will reach critical mechanical components to produce drive, support loads, reduce friction, and or carry heat away. The result is accelerated mechanical wear and or damage.

11. Temperature Control and Design.
As with internal combustion engines that have water cooling and thermostats that control the temperature to a relatively narrow range, thermostat control is also available for oil cooler systems to provide quick warm-up and or cooling down but is also designed to prevent over-cooling.

Performance Characteristics of ASA Hydraulik LL 06

12 Volt DC Fan Ventilated Oil Cooler.