Flooded AHU

The absence of an intended drain line, a leak or a blockage in the one that is installed are all possible causes of a problem like this. One must expect air cooling equipment to have a water waste stream, and install and maintain a suitable waste pipe accordingly.

There is already a drain line which is connected to condensed water pan and located under chilled water coil , also it's clear and works good.

the problem is the water which condensed out side condensation drain pan

Apply thermal insulation lagging to the equipment. Something that is waterproof will do fine. Outside moist air is coming into contact with cold surfaces and condensing on them. Lagging will reduce or prevent this from happening.

Lagging will also reduce the equipment's power requirements slightly.

the units are already isolated with double wall and thermal isolation in between.

no condense water at outside walls. but water comes from unit inside

Is there anything else that the forum needs to know?

Consider providing proper drainage to overcome flooding & it's related problems.

you are right. it's an easy solution .

but i would like to know why water leaves or skip condensing pan and accumulates outside in blower area

Dear bigg.

you are demonstrating our problem better than me. it's the right case we are facing.

are there any other probabilities for this issue

GA from me

This can be caused by oil residue on the coil causing the water to bead instead of clinging to the fins....Try spraying some low sudsing soap on the coil to increase the surfactant quality....This might take a few treatments...

good suggestion and easy treatment

thank you

The most important is stopping the condensate from the coil to occur, the fan has nothing to do with the source of the problems. take a second look into the chilled water flow rate, entering and leaving temperature of the coil. Once these parameters are properly adjusted, hence we will have the problem solved.

The suggestion regarding a dirty coil is a possibility BUT- make sure that the chilled water is flowing at the proper rate.

This is a wild guess, but- if flow is low, almost ALL of the moisture removal will come from the last row or two of the coils, rather than about two-thirds of it. The easiest way to check flow is entering and leaving temperatures.

Check the specified temperature difference for the coils- it should be around 5 to 8.5C differential with entering temp around 6C to 8C entering. If you are looking at leaving water temp of 16C or warmer, you have low flow and nearly all of the cooling (and moisture removal) is happening in the final coil or two, triggering over-spray because it is flooding the face.

Dear energygod

you are a real Veteran guru

GA for U

Check for blockage in the condensate drain line. It is very possible that all the AHUs experiencing this flooding; the drain pipes are connected together.

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It could be a case of dirty / blocked coil. The fan is partially sucking air through the coil and because the coils are dirty the excess air is sucked from the condenstate pan through the connecting drain pipe line resulting in floods at the motor drive side.This eventually flows out and floods the area.

Dear pillay

very logical conception and GA

thank you

Hi khairy: A couple of situations can cause the pan to not drain properly.

Start with the more common cause, a clogged drain line or an obstruction over the drain pan opening.

If neither of these is a culprit give a holler and I can furnish you more complicated suggestions..

Good luck.

Lou Bindner

Dear Binder

Drain line is not clogged. Waiting your complicating suggestion

I am thinking about U Trap condition for condensation draining line ........ We have face similar problem and fault is with the U-trap .......