Evaporative Cooler Aboard in the California Delta...???

[markpierce]

Oliver, I think the one big difference between our summer and yours is humidity. In the Delta, it's up to 20 degrees warmer than the bay, ...

I'll say it can often be 40 to 50 degrees difference. It can easily be 65 degrees in Pacifica and 105 degrees in the Delta, a distance less than 80 miles. Gee, a 20-degree difference between Oakland and Orinda (after passing through a tunnel under a ridge of hills) isn't uncommon during the summer Temperatures in the Delta vary/cycle. When the Central Valley heats up, it creates a low-pressure area drawing in cool Pacific air.

 

[N4712]

Oliver, I think the one big difference between our summer and yours is humidity. In the Delta, it's up to 20 degrees warmer than the bay, but the humidity runs about 30-40%. So at 90-95 degrees and 35%, it doesn't take much to make you feel cooler...a breeze (natural or fan), a dip in the fresh water, a FW washdown, a mister or an evap cooler.

Early this month, I was in the delta with those conditions and had a mister spraying in the cockpit. It worked well, cooling me and the decks. As the week went along, the temps cooled into the 80s and no mister was needed, just an occasional fan. Aside from an unplanned swimming event, I didn't feel the need for a swim with the temps in the 80s or lower.

When I travel back home to Chicago to see family or DC, I'm always impressed with the impact that humidity has on my comfort level. It's something I have long taken for granted out west, but my travels east help to remind me of our good fortune.

Oh, did I mention we have few bugs?

Very true i seem to be forgetting that. The humidity is absolutely horrid here.

Oh, did I mention we have few bugs?

If only we had no bugs!

 

[BruceK]

The evaporative cooling system is popular in OZ in dry/low humidity areas, large units sit on roofs. But use one in Sydney and other humid places and you`ll grow mould on the walls.

 

[Mule]

Works good in Kermit, Plainview, El Paso....try it in Beaumont or Houston....good luck.

 

[FlyWright]

Agreed. It's popular in Arizona and Nevada and here in Sacramento, too. It'll work in the Delta, but not where we berth our boat in Vallejo. There, it's a cooler and damper climate...more on par with San Francisco than Sacramento. It's quite common to start each summer day there with a marine layer overcast.

During our Delta trip, we were often wore jackets and long pants in the evenings after 8PM and shorts throughout the daylight hours. The closer I moved to the San Pablo Bay, the cooler it got. 30-40 degree temperature spreads at one location throughout the day is typical. In Sacramento, we can add 25-30 degrees to our 8AM temperature to estimate the high for the day.

 

[Astral Blue]

Inspired by Auscan's post, I have gathered the necessary parts for the 12V Redneck Bucket Swamp Cooler.

As you can see, I've used a supersized bucket that will hold about 4-5 gallons at the planned waterline.

I'll give it a go and report back.

Oh boy, Al...my thread has created a monster!

 

[psneeld]

I have never measured it so it might only be a guess...but wherever I have been...there is always a slight haze on the water at night...much more so than even the parking lot at the marina.

I come into the slip with the spotlight on and there's always a haze of what looks like moisture ...but in the parking lot...unless a strong breeze blows it up there...looks like less moisture.

So before I went through all the trouble of trying an evaporative cooler..I would take some readings at a level it would be on various nights you think you might need it over the water.

The "humidity reading" you get from the weather to me these days is suspect as I see so many backyard weather stations hooked into "weather services" that are clearly inputting incorrect info as the winds and temps on some are so far off they are comical....I wonder if a computer program throws out statistically off info????

 

[FlyWright]

PSN,

I did measure it in the Delta during my two week trip this month with my weather station. The humidity ran in the 35-40% range. That is the norm in these parts. You're far from the Delta so I'm not surprised that your weather is different.

 

[psneeld]

My issue with a swamp cooler in a "moist environment" like on a boat is that in the "dry areas" such as the whole delta region...rel. humidity will tend to drop because the available moisture isn't there but the temp. goes up. In the moist region (on the water) the evaporation skyrockets near the surface of the water and in a low wind situation when you most want cooling...I'm not sure the "performance numbers" of 20 percent would be there.

They might be...all I'm saying is before I spend the money and energy to install a system that often is not used in aquatic or marine app...that it may be worth looking into beyond anecdotal info.

 

[FlyWright]

I'm putting together the bucket swamp cooler in Auscan's link and will probably have less than $20 invested in this experiment. Not much money and energy at risk here.

Did you miss the part where I mentioned that I MEASURED the RH onboard at 35%. I saw it lower than that value, but that is a pretty accurate average during periods with the temps above 90 degrees. At lower temps, this cooler would not be needed or used.

I recall from weather school that a temp increase of 10 degrees C results in a doubling of the "air's capacity to hold water" (not technically correct, but useful for purposes of discussion). This means the RH can drop 50% with a 10 C temp increase. So a 50% RH at 68F (20C) can become 33% at 86F (30C) degrees.

 

[FlyWright]

Ok guys....here's the finished product. It's colors include Perkins blue, silver and FlyWright burgundy. Obviously I lack the creative artist gene so I had to go with stripes. My freehand art often gets confused with scribbling.

It's a 12V fan and a 12V pump. The power supply it's connected to is a 1.5A power supply. The fan is a 2-speed fan, but it apparently cavitates on high due to the low volume of incoming air. The sound level is much lower on low and I measured no difference in outflowing air temperature. I will connect it to a 12V power plug cord on the boat.

Here are the "before and after" shots of the temps today in my garage showing a nearly 20 degree F difference.

The airflow is not enough to cool a garage, but it might work well to drop the boat salon temp 5-10 degrees. It would also be helpful when directed toward a workbench or table when working in a warm setting such as a garage.

 

[Astral Blue]

Al, you da man!

 

[FlyWright]

I would have been done a couple of days ago, but I had to paint it. I didn't want some butt-ugly chlorine-tab bucket messing up the decks of FlyWright.

Besides, I've got plenty of fishing crap to accomplish that!

 

[CPseudonym]

Looks good Al

 

[ben2go]

Awesome.

 

[AusCan]

Fantastic job, Al!
Just remember that with evaporative cooling you don't want to seal off the room by closing all windows and doors. This will raise the room's humidity to a level where the cooler no longer is effective. Allow decent incoming and outgoing airflow, and the temperature will continue to decline. Experiment with which vent/windows are most effective.

 

[FlyWright]

Agreed. We used them in Arizona in the 70s....lived there for 5 1/2 years.

Maybe I should send this one to you in the desert, Auscan! Are you still there and can you use it?

 

[sbu22]

Don't know about the Delta specifically, but back when I lived out there a lot of folks in the valley and further up (Amador County) used swamp coolers with reasonable success.

As to prior comments regarding the climates in the Bay Area, the wrongly attributed to Mark Twain quote seems to apply: "The coldest winter I ever spent was a summer in San Francisco." Spent many a chill night standing forward capstan watches on fleet submarines (about 18" off the water) around Hunter's Point and Vallejo.

 

[markpierce]

Have my doubts FlyWright's device will not tip over as a result of a large wake or natural wave. A wider base and narrower top would seem to be more stable. ... Had a warm yet comfortable cruise eastward in San Pablo Bay earlier this week. The Bay was calm, with an easy breeze following the 2.5-knot tidal push toward Vallejo.

 

[RT Firefly]

Greetings,
Hmmmmm.......

Hmmmmmmmmmmmm....................

!!!!!!

 

[FlyWright]

Have my doubts FlyWright's device will not tip over as a result of a large wake or natural wave. A wider base and narrower top would seem to be more stable. ... Had a warm yet comfortable cruise eastward in San Pablo Bay earlier this week. The Bay was calm, with an easy breeze following the 2.5-knot tidal push toward Vallejo.

Always a possibility, but less of an issue on the delta where it would be used than the bay. TBH, it might never see service on the boat. We'll see...

 

[bligh]

You guys crack me up. A redneck swamp cooler. Can I get one in camo?

 

[bligh]

 

[AusCan]

Agreed. We used them in Arizona in the 70s....lived there for 5 1/2 years.

Maybe I should send this one to you in the desert, Auscan! Are you still there and can you use it?

Thanks for the offer Al, but I've escaped the desert for a bit of a holiday in the Ionian Sea. Its fairly humid here, so so not much use at the moment.

 

[FlyWright]

Thanks for the offer Al, but I've escaped the desert for a bit of a holiday in the Ionian Sea. Its fairly humid here, so so not much use at the moment.

Glad to hear that you're out of that quagmire and enjoying a well-deserved holiday. I bet you're enjoying some humidity.

Bligh, camo paint would have been the perfect paint job. Wish I had thought of that!! Maybe even a camo wrap.