Using a swamp cooler

Microlite Mike wrote:

wa8yxm wrote:

Now... One thing that might help (I STRESS MIGHT) might also make thigns worse is "Misting" the condenser. You want to mist the "inlet" side of the condenser (On most A/C's that is the side you can't see.. Coleman it's the side you can see)

How to do that safely is not something I wish to get into but they make mister nozzles for swamp cooling a patio. Two issues however.> Minerals can build up on the condenser clogging it. and discoloring it. and the dang mister nozzles like to clog.

I don't have central air in my house as it would be a $10K investment at this point but I do have three A/C units, one window and two portables, that make the house quite comfortable during thee 20-30 days per year that temps are above 80.

Each of these units have a "misting" system built in that merely sprays the condensate into the condenser cooling air stream. I;ve always wondered why RV A/C units don't use this same system and merely let the condensate flow out onto the roof where it dribbles on the ground where it's not wanted.

One could fairly easily provide the same effect by merely placing a portable patio "mister" on the roof, close enough to the A/C unit that the mist is sucked into the cover's openings and then through the condenser. No more dangerous than operating the A/C on a foggy day or in a light rainstorm.

Here's a $30 example available on Amazon:

As an added benefit it might provide some cooling to the roof which would translate to less heat being transferred into the living area.

The big downside to "misting" when using City Water is that Water is becoming extremely scarce in areas that are typically HOT. So much so that reservoirs are at record low levels. This may mean restrictions on this method by Park Owners.

Lastly, ANY evaporative cooling method, swamp cooler or mister, will generate a lot of mineral buildup on surfaces if the water source is not relatively "Soft". I've seen swamp coolers in Arizona that look like they've been sprayed with lime and their evaporation mats totally plugged with mineral buildup from the water used.

I use a misting setup for a roof top garden.. It helps some but not all that effective unless it is supplemented with shade. Keeping direct sunlight from hitting the RV is cheaper and far more effective solution.

Spraying a mist of city or well water into a roof A/C might sound like a good idea, but in practice if done long enough with very hard water (high mineral content) the coils will get a coat of minerals on the surface which will reduce the A/C units performance and be difficult to remove.

Natural rain water while it may have dirt particles in it, will be "soft" meaning no or very little hard water minerals like calcium, lime, iron.. The dust/dirt is far easier to remove than hard water minerals.

Permit this bit of thread drift...

Working as a boat captain I spent a lot of time in Mexico. Tropical Mexico is often very warm too downright hot and many restaurants utilize misting systems to cool their dining rooms. I often saw tourists make a beeline for tables that placed them under the misters...

Cue the music from Jaws, da cant, da dant, da dant. While most folks will insist on bottled water they lose sight the fact that those misters are filled with large buckets from a spigot out back. Those nice cooling water droplets end up on your food and that does not always end well if you get my drift. :S

Just sayin

:R

Desert captain, you do make a good point..

However in the case of my roof top garden, all of the water that is used from my misting setup comes from my same water well that we use for our household uses like shower, toilet, cooking, drinking..

So no worries about bad stuff being sprayed on my vegetables from my water well and even if there was, we would be sick or dead from direct consumption been drinking water from that well for 30 yrs now :)

And yes, untreated water from questionable sources which could contain harmful parasites or disease being sprayed in fine mist is a quick way to kill potential repeat customers and your business..

I lived for years in the desert Southwest; i.e., Phoenix. Even there my swamp cooler was of minimal benefit. It was great in the Spring and Fall but of no use in the Summer when most of the cooling was needed. Arizona has a "monsoon" season that typically starts by the 4th of July and runs through the end of Summer. There is very little rain but humidity does increase to modest levels, about 70%. At that point the swamp cooler could not keep up and added oppressive amounts of humidity.

Gdetrailer wrote:
Desert captain, you do make a good point..

However in the case of my roof top garden, all of the water that is used from my misting setup comes from my same water well that we use for our household uses like shower, toilet, cooking, drinking..

So no worries about bad stuff being sprayed on my vegetables from my water well and even if there was, we would be sick or dead from direct consumption been drinking water from that well for 30 yrs now :)

And yes, untreated water from questionable sources which could contain harmful parasites or disease being sprayed in fine mist is a quick way to kill potential repeat customers and your business..

Like I said my post was thread drift... I was only sharing the warning to prospective tourists headed to third world countries. I met some folks in Cabo who were sick as a dog for most of their stay and they swore they only drank bottled water and beer. When I asked if they had sat under the misters at the restaurant the light came on for them. :E

Not bad rapping Mexico per se, I have spent a lot of time down there for twenty years working and being a tourist but usually delivering boats back and forth between southern California and Mexico from Cabo to Manzanillo and everywhere in between.

I love Mexico though it used to be a lot safer before the rise of the Cartels. When traveling there I would shop and eat with the locals and I only got food poisoning twice... both times at high end hotel/resorts... beware of buffets on a hot day. :S

:C

With a swamp cooler you also want to make sure that you're pumping soft water into it. Our next door neighbor in AZ failed to do that and after a year or so our local hard water completely ruined his cooler.

Gdetrailer wrote:

eHoefler wrote:
A/C remove humidity to cool, you would have the 2 different systems fighting each other and will get nowhere. If you adding a unit, add an A/C

A/C "chills" or "cools" the air going through the coils and as a side benefit the chilled coils removes some moisture in the air as the warm moist air flows through the cold coils and condenses out some of the moisture which drops to the catch tray and out of the A/C unit.

A/C also reuses the interior air so each pass through the A/C unit more moisture gets removed. Each time cycled through the A/C unit the air coming out will get cooler since you are not adding outside hotter air.

OP has several ways they can go if current A/C is not cutting it. They could replace current A/C with a higher BTU unit, most RVs typically are outfitted with 13.5K BTU A/C units which in larger RVs may be marginal at best.. a 15K unit could be used instead provided they have enough amperage capacity on the shore cord..

A second 13.5K BTU A/C unit could be installed provided they have an extra roof opening to use and have a "50A" shore connection..

They also can of course attempt to find a nice shady spot under a canopy of trees.. The air temps under a good dense canopy of trees can be considerably cooler than if one was out in the open to direct sunlight.

But mixing refrigeration A/C with swamp cooler isn't going to work..

Yes & no on the principals involved (agreed, running both is not going to work).

Yes, the air/con directly cools the air and the dehumidifying is mostly a side effect.

But, once the air is dehumidified, it will "feel" cooler because in the drier air, the moisture on your skin will tend to evaporate more readily directly cooling you body.

If you are dumping a bunch of humidity back into the air from the swamp cooler, the air will be cooler but you won't get much if any evaporative cooling of your body. Result, is you have to keep the air/con temp setting a few degrees colder to get the same level of comfort.

The basic problem with using swamp coolers in areas where they work well, in an RV, while off the grid, is the quantity of water that they use on a daily basis. For example, at +95 degrees F and 20% humidity (typical desert environment where water is scarce) it wouldn't be unusual to use 3 to 5 gallons of water per day to cool a +-300 sq. ft. RV. If the humidity remains low, expect no more than a 20F drop in temperature. How much water do you typically carry in your RV?

If you happen to have a convenient readily available soft water source, . . . . no problem. If not, well, . . . . now you know why it's not a more popular idea.

Chum lee