is anyone using one of these AC units?

[StirCrazy]

hi I reacently stubbled across the Fresair web page and was looking at THIS unit. has anyone used an evaporative AC before and how did it work.

I am looking at this for on the camper (no ac or 120V yet) and it would only be a once and a blue moon thing as normaly I am high enough in the mountians to not worry about AC. With the ability to install it in an exsisting 14x14 vent and the low power usage (less than 8amps DC at full power) and the fact it doesnt need pure water so well water or what ever is at the campground would be fine...

Thanks
Steve

[StirCrazy]

Sir Lancelot wrote:
Please check out https://www.turbokool.net/Default.asp . Never used one, but thought this style was better than the Fresair version, and less money.

I don't think I would even consider that unit. First, it's a lot taller (over twice the height), but the main reason is it doesn't keep the moisture and air separated. It will put moisture into the air you are putting into the camper. This is why it is so cheap, it's just a humidifier in an airpath. The one I originally looked at said they can make the air colder but not pass the humidity over to the air which ensures you're not pumping wet air into your unit. To me that is worth the extra price if I end up going in this direction. but I will have to check into that more also. but the height difference alone would be my deciding factor.

Steve

[Sir_Lancelot]

Please check out https://www.turbokool.net/Default.asp . Never used one, but thought this style was better than the Fresair version, and less money.

[4x4van]

For those that are downplaying the effects of a "swamp cooler", I live in SoCal (born and raised), and have never had AC in my house. I have a single swamp cooler on the roof, blowing down through a single 20"x20" vent into the living room with about 1/3 of the louvers angled down the hallway. By cracking open a window in the bedrooms, it allows the air to travel into them, and forces hot air out.

No, it's not as cool as my kids' houses with A/C. But it is entirely liveable and significantly cooler than outdoors, as long as the RH is low (which it normally is here). It also barely makes a dent in my electric bill, UNLIKE my kids' A/Cs. And the "heat soak" that was mentioned above by GritDog and Rick Jay would apply to A/C units just as much as Swamp coolers, so that's kind of a moot point.

Remember, StirCrazy is not looking for the same effects of an A/C; he's looking for a way to occasionally cool down a small space with very low power requirements. And a small 12vdc swamp cooler fits that bill nicely.

[StirCrazy]

wanderingbob wrote:
Swamp cooler , google it , not an air conditioner as we think of one !

I think we established that in the first post. for what its worth I have experience with evaporative cooling for 20 years in the navy as that is how they cooled the ships.

Steve

[StirCrazy]

Rick Jay wrote:
StirCrazy,

You may have seen this on their website, but if not, here's a chart showing How Much Cooling Can Be Expected. I as looking for data about what the equivalent cooling capacity in BTU's would be for comparison, but I didn't see any numbers provided. I guess it would vary widely based upon the temperature and humidity, or it just doesn't make the unit look favorable in comparison.

I guess only you will really know or can estimate the range of temperatures and humidities you'll face. But looking at that chart, I don't think such a unit would provide much, if any, relief for the majority of the U.S. during the summer time.

One thing to remember, as Grit Dog was pointing out, is you not only have to cool the air in the RV, but everything that is inside the space as well. All of that holds heat energy. Getting the "air" alone 20 degrees cooler will not offer much comfort as that air will absorb the heat contained by the stuff inside. That's why it will take A LONG time to cool down a space.

You mentioned you would rarely be in a situation to use this and suggested that you'd have water at a campground to use it. Just a question: Would said campgrounds also have electrical hookups? If so, since this is going to be a rare occurrence, I'd ponder about putting in a smaller conventional A/C (maybe a used unit) and just plug in when needed. Or, perhaps one of those portable A/Cs you plug in but vent out a window. You'd have to store it when not in use, though.

Obviously if you visit campgrounds that don't provide A/C, then these ideas wouldn't work. 🙂

Good Luck, and please let us know what you ended up doing.

~Rick

no, no power whatsoever, that's why I have a 10-day reserve battery power in case the solar panel fails. What I meant by rarely in a situation to use it, is that usually I am up high enough in the mountains or in a cooler climate zone where you just don't need AC. but there is the odd time I am in areas where it is 100F or a bit warmer. Generally, it cools off quick at night so if you stay up lait enough you're fine but I'm not as young as I used to be for howling at the moon haha. according to your chart I can expect a 25ish degree reduction in air temp, and I understand what you are saying about it has to pull the heat out of the inside of the rv, so ya I would crack the two vents then run this full blast and within an hour or two it would be cooler in the camper as the cool air flow would also carry the heat out the vents.

[wanderingbob]

Swamp cooler , google it , not an air conditioner as we think of one !

[Rick_Jay]

StirCrazy,

You may have seen this on their website, but if not, here's a chart showing How Much Cooling Can Be Expected. I as looking for data about what the equivalent cooling capacity in BTU's would be for comparison, but I didn't see any numbers provided. I guess it would vary widely based upon the temperature and humidity, or it just doesn't make the unit look favorable in comparison.

I guess only you will really know or can estimate the range of temperatures and humidities you'll face. But looking at that chart, I don't think such a unit would provide much, if any, relief for the majority of the U.S. during the summer time.

One thing to remember, as Grit Dog was pointing out, is you not only have to cool the air in the RV, but everything that is inside the space as well. All of that holds heat energy. Getting the "air" alone 20 degrees cooler will not offer much comfort as that air will absorb the heat contained by the stuff inside. That's why it will take A LONG time to cool down a space.

You mentioned you would rarely be in a situation to use this and suggested that you'd have water at a campground to use it. Just a question: Would said campgrounds also have electrical hookups? If so, since this is going to be a rare occurrence, I'd ponder about putting in a smaller conventional A/C (maybe a used unit) and just plug in when needed. Or, perhaps one of those portable A/Cs you plug in but vent out a window. You'd have to store it when not in use, though.

Obviously if you visit campgrounds that don't provide A/C, then these ideas wouldn't work. 🙂

Good Luck, and please let us know what you ended up doing.

~Rick

[StirCrazy]

4x4van wrote:
If StirCrazy is considering this unit for his camper (1991 Slumberqueen WS100), then it will likely work well for him (assuming low RH), since the camper is a much smaller volume of air. My dad used a version of this on a truck camper back in the late 70s, and it worked surprisingly well. Of course we were camping in the desert, so anything at all was an improvement! OTOH, if he's considering it for his TT (2016 Cougar 330RBK), then he's barking up the wrong tree entirely, if not the wrong forest!

haha no it's for the camper and I did say that in the original post LOL. The 5th if anything needs a second AC installed on it, well at least it needs me to pull all the vents and such and make sure the racetrack and cut outs are all sealed up properly.

The issue I am having is the actual cost of a swamp cooler that I may or may not use at all in a season.

[4x4van]

If StirCrazy is considering this unit for his camper (1991 Slumberqueen WS100), then it will likely work well for him (assuming low RH), since the camper is a much smaller volume of air. My dad used a version of this on a truck camper back in the late 70s, and it worked surprisingly well. Of course we were camping in the desert, so anything at all was an improvement! OTOH, if he's considering it for his TT (2016 Cougar 330RBK), then he's barking up the wrong tree entirely, if not the wrong forest!

[Grit_dog]

^But it is “sort of” a run it 24-7 kind of thing.
That’s what I was trying to say. Now I can’t say how long that thing will take to cool down the camper exactly, but after having multiple homes with swamp coolers, it’s nothing like an air conditioner.
Appropriately sized on a house takes hours to cool it down a significant amount. And taking advantage of early morning cooling effect helps through the day.
You’re not going to walk in to the camper late afternoon when it’s been baking in the sun all day and flip on the swamp cooler and get any immediate effect. You’d want to turn it on well ahead of time to get any benefit out of it in the heat of the day.

If you’re wanting immediate evaporative cooling, a personal swamp cooler works. (Wet towel over bare skin, stand in front of the fan. Lol)

But yeah if you want to theoretically turn it on in the afternoon to have it conditioned for bedtime I could envision that working. But I can only speak from experience with residential systems.
They work great, in Albuquerque. Not so much in Phoenix.

[StirCrazy]

Grit dog wrote:
At 20% relative humidity or less, evap cooling works pretty well.
But remember you’ll be running it virtually constantly unlike a normal AC.
When it says “cools 30 degrees at 90deg ambient and ____% humidity” or whatever the claim is, that is the air temp coming out of the machine. Unlike an air conditioner that spits out 40deg air or whatever.

yup from march to october out avrage RH is under 20% so I understand how its rating is a drop of air temp not a output temp, so at 104 degrees F w if everything is perfect I could expect about 64 degree air blowing inside but even if I got 80 for an hour to take the edge off before you go to bed I would be happy. this isn't a run 24/7 thing as I don't sit in the camper all day, I am only in there to get stuff, go to the washroom, or go to bed.

[StirCrazy]

pianotuna wrote:
I tried it two ways. Once in the entire RV where it was more or less useless. Then in just the bedroom where it managed 3 f. (category nearly useless). The bedroom was isolated with a sliding vinyl door during the testing.

For our friends who don't know the climate in Saskatchewan, it is semi arid with low humidity--some times the RH gets as low as 4%. Other times we have 84%.

On some occasions I've run a humidifier in the winter time in the class C.

I think comfort might be better reached with a large volume of air fan.

ya the problem with kamloops area when its 40 degrees out thats what you bringing in with the fan haha. our normal RH from march to october is less than 20% then in the winter it goes up to 40 for two months then settles out about 25 for the rest...

[pianotuna]

I tried it two ways. Once in the entire RV where it was more or less useless. Then in just the bedroom where it managed 3 f. (category nearly useless). The bedroom was isolated with a sliding vinyl door during the testing.

For our friends who don't know the climate in Saskatchewan, it is semi arid with low humidity--some times the RH gets as low as 4%. Other times we have 84%.

On some occasions I've run a humidifier in the winter time in the class C.

I think comfort might be better reached with a large volume of air fan.

[Grit_dog]

At 20% relative humidity or less, evap cooling works pretty well.
But remember you’ll be running it virtually constantly unlike a normal AC.
When it says “cools 30 degrees at 90deg ambient and ____% humidity” or whatever the claim is, that is the air temp coming out of the machine. Unlike an air conditioner that spits out 40deg air or whatever.