Water cooled condenser

[airtight_tech]

So I am constructing my own water cooling system For my condenser. From my research it should give me better temp drops and shorter cycles on hot days. Has any one tried this, are you happy with the results? What brought this on is my ac is sized kinda marginal and has trouble keeping up with the load on really hot days. Which brings me to my next question would upsizing my coil by a ton and a installing a txv gain me any more sensible capacity??

[Shophound]

So I am constructing my own water cooling system For my condenser. From my research it should give me better temp drops and shorter cycles on hot days. Has any one tried this, are you happy with the results? What brought this on is my ac is sized kinda marginal and has trouble keeping up with the load on really hot days. Which brings me to my next question would upsizing my coil by a ton and a installing a txv gain me any more sensible capacity??

I'm curious what you mean by "water cooled condenser". Shell and tube? Coaxial? Controlled by a pressure operated flow regulator to maintain between 100 and 105 degrees saturated condensing temperature?

Or are you just spraying your air cooled condenser coils with a lawn sprinkler or patio mister? This method will get you in trouble within one cooling season. Trust me.

There are many other ways to make an a/c system that is a marginal performer on very hot days do a lot better than spraying water on the condenser coils. The biggest one?

Reduce the heat load on the house!

[airtight_tech]

Sorry i should have been more clear, kinda like a patio mister. There is something called a Kool Mist system that is on the market i was going to construct one myself. I know that an AC loses somewhere around 20% of its capacity as ambients approach 105. due to its inability to transfer heat as effectively. By misting the sorrunding area I should be able to bring ambient down by approx. 20 deg. meaning at 105 ambient my condensing unit could opeate with full capacity and with potentially its full SEER efficiency on even the hottest of days. Why would this give me trouble? As to reducing heat gain on the house its my inlaws i rent it from them and wont be here all that much longer (hopefully less then a yr), besides i pay the utilities so hes not to worried about it lol

[Gunnery Sergeant Hartman]

How much capacity and efficiency will you lose to mineral and scale build up from the water evaporating?

[airtight_tech]

I thought about that the kool mist system comes with a filter I could do something similar. I also clean my coils twice a cooling season with coil cleaner. Don't know his much this helps wih scale and mineral deposits tho. I also thought about rigging it up to run in only high ambients to conserve water and minimize build up. Any one know if upsizing my coil will gain me sensible capacity currently it's matched to my condenser tonnage. Also curious about this flow reg. To limit saturation temps is this like a txv kinda for your condenser?

[Shophound]

Like I said, trust me on the mister.

I said what I did to gauge where you are with this.

Upsizing the evap coil while leaving the condenser coil the same will give you a sensible boost...maybe. And if you get it you'll gain it at the expense of latent capacity.

Reducing the heat load on the house will get you much further down the road than tweaking on your A/C equipment. Maybe not as fun but it's more effective.

The flow reg is for the coaxial or shell and tube condensers I mentioned in my OP.

[airtight_tech]

What ramifications would water cooling have on an air cooled condenser? Not doubting the validity of your statement I am just curious. And I am in agreement if it was my house I would reduce heat gain cause it's much more beneficial then compensating for my buildings envelope issues with equipment.

[Shophound]

Other than the scale concern, it's possible to reduce capacity of the system if you overcool the condenser coils with water, especially if you don't have a TXV on the system.

I know, this sounds counterintuitive. Lots of stuff is in physics. But a DX system that uses a fixed orifice metering device depends on head pressure to flow the right amount of refrigerant through the evaporator under a given heat load (so does a TXV, but it is a more precise metering device). If head pressure drops too far, it will reduce the pressure difference (delta P) across the orifice and as a result reduce the mass flow of refrigerant through the evaporator.

In other words, if at peak load you need to circulate four pounds of refrigerant per minute through the evaporator, and by reducing head pressure with a water mister/deluge device you lower the pounds per minute to three or 2.5, you've reduced the capacity of the system to remove heat from your indoor air. Sure, you may get a colder coil, but the amount of refrigerant in the coil will finish boiling sooner and enter into superheating faster, where little work is done. Once an evaporator begins serving as a superheater for refrigerant, it isn't doing much work cooling and dehumidifying.

I've seen this happen many times with window a/c's and PTAC's. The condenser coils would be soaking wet and I thought it would in turn be pumping out bone chilling cold air. Not so. The air coming out of the unit actually felt clammy instead of that nice, refrigerated cold sensation.

[paul42]

There used to be a company that made a water cooled condenser unit. I don't know if they are still in business or not.
The condensing coil was in the bottom of a pan of water. The fan pulled air through swamp cooler type pads. Water was pumped from the pan in the bottom over the pads which drained back to the pan. It used condensate for some of its supply of water, and the rest from the water main.

[bmathews]

It seems that putting a couple of hundred dollars worth of insulation in the attic will cost the same or less than constructing a misting system and the cost of the amount of water that you spray on the condenser to keep it cool. Not too mention the risk of tearing up the equipment and the added wear and tear you will put on a piece of equipment that was not designed to do what you are trying to do.

[airtight_tech]

Increased superheat from reduced head pressure wasn't something I had considered. But for the sake of argument if it was constructed to come on say at 100 degrees It should have an ambient of approx 80 deg. it should be enough for significant headpressure (ecspecially if it had a txv) or if we took it a step further you could even hook the mister up to be controlled by the head pressure like a condensing fan cutting out for low ambient conditions.

[sammy37]

There used to be a company that made a water cooled condenser unit. I don't know if they are still in business or not.
The condensing coil was in the bottom of a pan of water. The fan pulled air through swamp cooler type pads. Water was pumped from the pan in the bottom over the pads which drained back to the pan. It used condensate for some of its supply of water, and the rest from the water main.

I think that unit was the first type of setup that either Freus used, or someone tied in with them used. That model is gone
Freus makes or made, I think they went under? A water cooled unit that ended up being a POS.

[sammy37]

Everyone thinks water filters are the ultimate cure for eliminating scale, they are not.

If you really insist on precooling your unit, then you need to do it with a setup that would use a cooling media, kind of like a swamp cooler would use.
This way, you would be keeping the water off of the coil but the moist air will still eventually jack up your coil.
We tried this type of setup on a unit once and it didnt save enough to make it worth the hassle.
Also, if you live in a humid enviornment, the evaporative method wont do squat.