Water mist help cooling my AC condenser unit

[refrepairman]

Spraying or misting mineral latent water on to an air cooled cond coil is like giving it a crack pipe. It wil be very happy and feel real good. It will however develop an addiction. It will eventually refuse to operate without it as well as demand more and more. The minerals will plate out on the coil insulating it requiring more water and so on. The cooling tower comparison is invalid due to application. A cooling tower flows warm water over the fill, same temp as the water, and air is drawn through to absorb the heat from the water. Cool water sprayed onto a hot coil will cause the minerals to plate out much much faster and directly onto the coil.

Agree.

[Trehak01]

I can see this as increasing the surface area of the condenser for it to reject for heat, however thats not how the engineer designed the equipment. I have replaced many of coil because a homeowner installed or a contractor sold them one of those mist sprays.. 8 months later Im there replacing the coil because the minerals in the water broke down the metal in the coil.

[RoBoTeq]

If you are pumping it on Goodman units.....

Yes, I have pumped condensate onto Goodman units, and they hold up just fine. In fact, when I inspected condensing units in Cayman after Hurrican Ivan all but wiped out Grand Cayman, the old Goodman condensers with the cheap black coating held up second best of all of the brands I inspected.

I was working under Carnak from this forum (recently deceased), and the only thing we could figure out was that because Goodman coils are the only coils manufactured using non-evaporative oil, that there must be a residual coating that protected the Goodman coils.

[RoBoTeq]

Condensate does not contain minerals because it was previously water vapor.

[Dallas Duster]

I would think that would also go for conditioned water from a water softener too??

Condensate does not contain minerals because it was previously water vapor.

[crazytekkie]

I dont disagree that minerals are a problem and depending on the water in ones town more so some places than others. Yes aluminum can have issues with some descalers but Im telling you thru actual experience and doing the deed not just theorizing how it should act that it works and works well. Obviously this is more practical on smaller AC units that are ground based so a person can monitor build up and address it with demineralizing easier and we arent talking using a full concentrate descaler nor waiting until your cooling fins have become so encrusted that its impossible to remove all deposits. My applications did not needed any sort or actions and it ran all summer in Las Vegas. In fact the light amount of depositing that did happen seems to saturate with water and actually improved cooling even better. This isnt a cure all without some intervention. There is always a trade off. You need better cooling, you are going to have SOME more work than just leaving things status quo but it works and works well. I havent spent years of R&D to perfect the application as I'm not looking to promote some sort of sale of a product to do such a thing, I did it with items kicking around the house and common sense knowledge and experimenting. And it worked.. Most on here just give a short bashing on an idea without knowing although there have been some with actual helpful thoughts and truths. I think many are so content with how things are in general on any topic that they would bash an idea out of looking into further. ANyone still content with the horse and buggy?? Why do we need cars?

[timtanguay]

hey Kevin , could you elaborate on your statement "overall freon flow will be reduced , lowering total cooling"........does misting the condenser make that large of a difference to the unit subcooling to affect its performance????? I was going to post about fouling the condenser also . at o'hare airport we found a rooftop full of units that were repainted But no one told the workers not to paint the coils , subject for a different thread.........Jack

Most systems are designed for a 90F design day temperature, corresponding to a saturated condensing temperature of ~120F (on standard efficiency coils). Metering devices are calibrated to work best at these specs. Metering devices work off of a pressure differential between the high and low side. If your head pressure is too low, then refrigerant flow suffers. You can kind of think of it as a push-pull kind of effect. This is why, in areas like Coastal British Columbia, where you are lucky to see 10 days a year reach 90F we have condenser fan cycling, which artificially raises the head pressure.

[RoBoTeq]

Hell...no! Water softeners are terrible! Where do you think that tank full of minerals goes?

[motoguy128]

No way there enough benefit offset the risk.

So instead of a eer of let's say 12 on a new unit at 90f, we get the dry bulb temp to 80f, so we improve to what 14? What that 15%. Big deal. How much maintenance and water do you need. If the condenser users let's say 1500cfm, you'll need 2gph evaporated to cool the air 10f. 1/2 of that could be supplied by condensate. But you need nozzles and a small pump. For a proper setup, you could be into it for quite a bit of money.

For the coast of all that, you could just have bought a higher seer unit in the first place or added insulation, sealed air leaks in the home, etc.



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[Dallas Duster]

Here is company that offers something similar on a large scale and they use a water softener when it comes to water treatment.

http://www.evaporcool.com/

[Tommy knocker]

I dont disagree that minerals are a problem and depending on the water in ones town more so some places than others. Yes aluminum can have issues with some descalers but Im telling you thru actual experience and doing the deed not just theorizing how it should act that it works and works well. Obviously this is more practical on smaller AC units that are ground based so a person can monitor build up and address it with demineralizing easier and we arent talking using a full concentrate descaler nor waiting until your cooling fins have become so encrusted that its impossible to remove all deposits. My applications did not needed any sort or actions and it ran all summer in Las Vegas. In fact the light amount of depositing that did happen seems to saturate with water and actually improved cooling even better. This isnt a cure all without some intervention. There is always a trade off. You need better cooling, you are going to have SOME more work than just leaving things status quo but it works and works well. I havent spent years of R&D to perfect the application as I'm not looking to promote some sort of sale of a product to do such a thing, I did it with items kicking around the house and common sense knowledge and experimenting. And it worked.. Most on here just give a short bashing on an idea without knowing although there have been some with actual helpful thoughts and truths. I think many are so content with how things are in general on any topic that they would bash an idea out of looking into further. ANyone still content with the horse and buggy?? Why do we need cars?

Congrats on getting yours to work at an acceptable level for you. As for experience in this subject? I have lots. Replaced A LOT of coils due to this I bet I can make it work better idea. I remember a large super market with a couple racks and several remote refer condensers off the top of my head. They had a maint staff that thought they could make them work better. Made a real pretty distribution system with nozzles and everything. Destroyed every coil in one summer. Oops. Like I said its a crack pipe for air cooled refrigeration systems. They love it. Love it to death.

[mark beiser]

My water ain't free, and it has chlorine in it.

[Freightshaker]

Water them down! Easy money

[ironpit]

I don't think you have been around enough to make such judgements against the members of this site. This is the best hvac site on the net.

Technically speaking, the guys this site are very good. The ones that aren't, are learning.
a small number of them tend to be " opportunists in offense". But that is to be expected. (personal thing)

The greater number of guys at this site are not just Do it yourselfers.

THEY HAVE YEARS OF PROFESSIONAL TRAINING

And I promise you, the guys running this outfit are as good as any and far better than most! You cannot find better.

And I am not a butt kisser. I've already ran afoul of some of them.

Most on here take this profession seriously, that is the reason they are on here. You are not going to find a more condensed grouping of helpful thoughts and truths on hvac anyplace else.

[motoguy128]

Let's make this even simpler.

If a split air cooled condenser was intended to be listed, what design changes would it have.

For starters a stainless steel find and coils....and frame and pan.

Air cooled condensers are designed to be air cooled. If you want evaporative cooling, get a small cooling tower and shall the water treatment and blow down controls, then install a water cooled heat pump out better yet a chiller.



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[RoBoTeq]

Some of you are really trying to make this much more difficult than it is. Just take the condensate line that you already have going from the indoor coil to the outdoor unit area and direct that water onto the outdoor coil. No additional pumps, no nozzles, just reroute the condensate line.

If you want to get a little better control of when condensate is introduced to the coil, have the condensate empty into a container with a solenoid valve connected to a 1/4 tube with holes in it run around the top of the outdoor coil. The container fills up whenever condensate is running out of the condensate drain, but doesn't allow that condensate to flush over the coil until the unit turns on and the container solonoid valve is opened.

[ironpit]

soooo........How much bucks are we saving with all this?

[Tommy knocker]

soooo........How much bucks are we saving with all this?

IMHO it will cost more then it will ever save. The 10-20 bucks a month, possibly, in electric savings will be offset by the additional cost needed to prevent or remove the scale. I mean really if it was a good idea wouldn't we all do it?

[boilerman856]

I dont disagree that minerals are a problem and depending on the water in ones town more so some places than others. Yes aluminum can have issues with some descalers but Im telling you thru actual experience and doing the deed not just theorizing how it should act that it works and works well. Obviously this is more practical on smaller AC units that are ground based so a person can monitor build up and address it with demineralizing easier and we arent talking using a full concentrate descaler nor waiting until your cooling fins have become so encrusted that its impossible to remove all deposits. My applications did not needed any sort or actions and it ran all summer in Las Vegas. In fact the light amount of depositing that did happen seems to saturate with water and actually improved cooling even better. This isnt a cure all without some intervention. There is always a trade off. You need better cooling, you are going to have SOME more work than just leaving things status quo but it works and works well. I havent spent years of R&D to perfect the application as I'm not looking to promote some sort of sale of a product to do such a thing, I did it with items kicking around the house and common sense knowledge and experimenting. And it worked.. Most on here just give a short bashing on an idea without knowing although there have been some with actual helpful thoughts and truths. I think many are so content with how things are in general on any topic that they would bash an idea out of looking into further. ANyone still content with the horse and buggy?? Why do we need cars?

I can say I have plenty of experience with this situation. When I started here 15 of the 25 ton carrier RTUs had sprinkler s running on them all summer for the previous few years. They were still locking out. The condenser coils were packed with minerals, airborne dust and grime because the coils were wet and now deteriorating so bad the flaking aluminum was getting sucked into the ofm windings. I tried absolutely everything but could not save them. It has taken me 2 summers to change all those 4 inch thick coils at 5500. Each! Plus all the ruined fans at several hundred and 3-4 semi hermetic compressors. If you do the math I don't think they saved much.

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[RoBoTeq]

Using condensate, I save money in energy, the system is able to handle the load better and there is no issue with any minerals or scale.