Using a swamp cooler

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

I used one to good effect in Arizona.. Not so much in Michigan. (For reasons already discussed) In AZ I also had to use nose spray due to the dryness of the air.

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.

Gdetrailer is correct. The key to a swamp/evaporative cooler is having the right/conducive environment. At this moment it is 103 outside with 25 percent humidity. My swamp cooler in our 1,400 square foot home is cranking on high and delivering 24 degrees of cooling for a very pleasant 79. I should note that once the temp rises much above 101 - 103 the efficiency will fall as it will if the humidity is greater than 30 percent and less is better.

Most RV AC systems struggle to give you 20 degrees of cooling and few if any will give the 24 - 25 degrees I routinely get from the swamp cooler. The problem that I see is they are hardly adaptable to an RV unless it is permanently parked. Coolers are by necessity fairly bulky, need a steady albeit light stream of water to replace the water lost to evaporation as the rest of the water just recirculates via an AC driven pump, ours is a one half HP model that draws very little current rendering it very cost effective.

When riding motorcycles here in Arizona in the summer we utilize so called wet vests which effectively are portable swamp coolers. You soak the vest completely in the coolest water available and as you ride the evaporation is very effective at cooling your core. Riding in 100+ degrees become es doable though you have to stop and re wet it about once an hour.

:C

If you're talking about the San Francisco area (as in your profile), your relative humidity is 73% right now. A swamp cooler won't help a bit and will only make things more uncomfortable. The good thing about "refrigerated" ACs is that they're also great dehumidifiers.

Rob

depends on your climate as to how well they work or don't work.

Swamp coolers are not effective/efficient/work in high humidity environments and in those environments adds more unwanted humidity making an already uncomfortable environment a humid, unbearable tropic forest environment.

Dry desert, sure, don't try that here in muggy PA or even the south eastern states like NC, SC, GA..

Swamp Cooler 101

"the evaporation of liquids caused heat loss. What he described in his letter is evaporative cooling

Swamp coolers work by harnessing that cooling reaction — you just need a way to circulate the now-cooler, more humid air through the house.

with a swamp cooler, it's much simpler. The main thing inside is a blower — a fan at one end of the box that brings air in from the outside and pushes it into the house at the other end. Before the air goes into the house, it passes through a set of damp pads, where the evaporation takes place. The cooler air goes into the house and the warmer air is pushed out. A small pump keeps the pads moist, so the water doesn't just evaporate away completely.

Swamp coolers are an open system. They rely on the flow of air through the building to direct the cool air, and since they always need hot, dry air to evaporate the water, it needs to displace the air already in the house.

Swamp Cooler Downsides

For all their benefits and cost savings, swamp coolers still only work in the right climate, and that unfortunately doesn't include areas like Philadelphia.

It needs to be not only hot but also dry

If the air gets too saturated with water, the water condenses. One hundred percent humidity outside the house means it might rain, and while a swamp cooler won't cause a downpour in your home, it won't have any cooling effect either — just the hot, sticky feeling you might associate with swamps. Your perspiration doesn't evaporate into the saturated air."

If you have one and are in the right environment use it.

If you don't have one and are not in the right environment, don't buy one, it will fail to make you feel comfortable..

True story, couple of yrs ago, when 6 out of 9 HVAC systems failed in the large warehouse building I was working in during a blistering hot and muggy summer the company rented a dozen huge portable swamp cooler fan systems which sprayed a fine mist of water into a high power fan air stream.. Yeah, that didn't work as I predicted to company management, didn't drop the temps in the building and basically made a huge amount of noise and everything felt even hotter and sticky/muggy..

If you are in the desert with very dry air, they work well and no need for air/con.

If you are in more normal conditions, it will only make the place humid like a jungle.

Too much humidity is a bad thing inside a RV…mold, wet windows.

If you like humidity, sure.