Air side fouling resistance of Air coolers

Hi,
Attached a comparison table for air coolers, none of the vendors are considering dirt coefficient on the air side.
Make sense to me, regular cleaning of the fins is required.
Note: Brochure from Hudson
Pierre

This is a heat exchange ristiance, nothing to do with air resistance.

It seems to say that this allowance should be used in the overall heat transfer coefficient to allow for some level of fouling but look to me to be a very low number.

So even with 50K difference in temp this is only 0.0017 W/m2. That's nothing. Have you got the units right?

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Agreed, the resistance is assigned to the tube side exposed to the air and to accommodate degree of fouling and dirt accumulation on the tube side of the air cooler. The mentioned number is confirmed with the units in m2. K / W2 and value of 0.00035 which is comparable to other process applications like gas and crude oil.

Hi,
A link underneath with several examples, to confirm my thoughts.
By the way, the fouling coefficient seems to be for liquid inside the tubes.


Pierre

You've just stated a completely different set of units...

"W.m2/K " in the OP, now "m2. K / W2"

What is it ?



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

Sorry there was a typo error, the unit of the fouling resistance is 1/U = m2.K/W

I agree with pierre and your OP - this is more like the internal fouling factor - see
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.