over cooling the condenser ?

[kerrcell]

Hi GUys,

I want your views for a horizontal air cooled twin condenser coil.Have been to a system that runs around 14 identical air conditioning systems.Someone have introduced a high pressure water system to spray mist from the underside of the condenser coils for better cooling,especially in summer when it rises to 40/40 degrees celcius!

Now my query is this.Can the water misting be overcooling the condensers ,this besides corroding the alum fins !I think more liquid refrig will be present.Can this lead to over charge circumstances,compressor floodbacks,etc...The compressor is in the floor standing unit,so only the condenser coil and fans are outside.Both head and liquid line pipes are insulated .Any views on this ?

[cadwaladr]

with so little info,type of refrigerant,pressures,and temperatures its difficult that info would help,if your spraying water onto cond whats the temps with water/without?

[cool runings]

.

Condensers can cool the liquid too much but it will not affect the system in the way
you think. Subccoled liquid out of the cond is good and within reason the cooler the
liquid suplied to the expansion valves the more efficient the system will be.

The problem you may find is the expansion valves need a certain pressure differance
over them to work correctly and if you drop the head (discharge) pressure too low you
may get problems with the evaps being starved of liquid (not flooded).

You are right to be concerned about the cond corroding though and for that reason
spraying water into the cond is not ideal.

The thing is though it is a very easy, cheap and effective way of increasing the capacity
of the cond on warm days.

coolrunnings

.

[cadwaladr]

just read the post again ref the corrosion it depends how acidic the water is i guess,is there ambient controls /fan speed controllers fitted to this plant?.

[mad fridgie]

If the spray head is indeed a mister, then there should be very little free water entering the cond, the air will be cooler with a very RH, the water should be used as an air cooler not a direct refirgerant cooler, liquid pressure pressure really does depend upon how the fans are controlled

[Magoo]

I would generally only recommend added mist sprays to an air cooled condenser if the condenser was on its last legs and waiting for a replacement to become available.
The water will seriously increase the crevis cathodic corrossion, and build up calcium deposit everywhere. Plus it is a waste of water.

[kerrcell]

Yes actually the condenser fan motors are pressure switch and variable controlled.