Aeration and Water Temperature

[Cluckr7]

I know this is an old thread.

I got an aerator that sprays a rainfall pattern of drops about 8 feet into the air. I was trying to measure if it actually did anything. The pool did seem maybe three degrees cooler but it’s hard to control for ambient weather conditions (cloud cover, humidity, wind).

I decided to run a poor man’s test and put a cup under the bottom of the rainfall pattern (just before it falls back into the pool) to collect some water and tested the temp relative to the pool water temp with a high end kitchen thermometer.

There was about a 2 degree difference (91 deg water to 89 deg water). This was during the peak of the day at the lowest relative humidity (around 40%) and around 98 degree air temp.

I was hoping for a much larger temperature drop. I would think that given the flow rate through the aerator (I would guess around 10 gpm), vs my pool volume (20k gal), that mixing in 10 gpm of 2 degree color water into a 20kgal pool would not do much. Running 24 hours per day wouldn’t even turn over the pool volume once, and that doesn’t account for the loss of effect due to mixing, or with a likely lower delta-T at night when the relative humidity is near 100%.

I still run it for a day before I expect to swim, but not sure if I’m just running it for a placebo effect, haha.

 

[Dirk]

I know this is an old thread.

I got an aerator that sprays a rainfall pattern of drops about 8 feet into the air. I was trying to measure if it actually did anything. The pool did seem maybe three degrees cooler but it’s hard to control for ambient weather conditions (cloud cover, humidity, wind).

I decided to run a poor man’s test and put a cup under the bottom of the rainfall pattern (just before it falls back into the pool) to collect some water and tested the temp relative to the pool water temp with a high end kitchen thermometer.

There was about a 2 degree difference (91 deg water to 89 deg water). This was during the peak of the day at the lowest relative humidity (around 40%) and around 98 degree air temp.

I was hoping for a much larger temperature drop. I would think that given the flow rate through the aerator (I would guess around 10 gpm), vs my pool volume (20k gal), that mixing in 10 gpm of 2 degree color water into a 20kgal pool would not do much. Running 24 hours per day wouldn’t even turn over the pool volume once, and that doesn’t account for the loss of effect due to mixing, or with a likely lower delta-T at night when the relative humidity is near 100%.

I still run it for a day before I expect to swim, but not sure if I’m just running it for a placebo effect, haha.

I'm pretty sure the results you're after are not actually from the temperature difference achieved by shooting water through the air. I seem to recall it has more to do with evaporation. I think maybe @JoyfulNoise would know, or would know who would know.

 

[JoyfulNoise]

I dunno … fountains seem like a waste of time to me. I have one and it’s never really done much. But evaporative cooling is real and it’s glorious!! Overnight my pool will cool off by several degrees just from evaporation of the surface water. We have low RH most days and nights and the dew point is always 20-30 degrees lower than the water temp so the driving force for evaporation is huge. In more humid climates, the dew point is very close to the water temp so there’s very little cooling overnight.

 

[Cluckr7]

I'm pretty sure the results you're after are not actually from the temperature difference achieved by shooting water through the air. I seem to recall it has more to do with evaporation. I think maybe @JoyfulNoise would know, or would know who would know.

I thought the point of spraying water in the air in fine droplets was to promote evaporation, and the result is the water droplets that fall back into the pool are cooler.

 

[zea3]

I live in high humidity Houston and ran my fountain during the day for a couple of hours during the heat of the summer. I never measured the tempature difference, but it felt a lot cooler hanging out under the arch of the fountain.

 

[Dirk]

Sorry, I don't have any experience with this issue, as my climate doesn't require any pool cooling. Just bumping your thread.

 

[wdsheffer]

I've only had this pool a few weeks, and I don’t know how well aeration will work when this high pressure moves out and the humidity comes back, but my water had been reading 94.5° pretty consistently in the evenings (using an instant-read meat thermometer), until I figured out how to turn on the aerators Monday. They were running along with the spa fountain a good part of Monday and without the fountain all day Tuesday. By bedtime Monday the water was 93°, Tuesday morning 90°, Tuesday night 90°, this morning 87°. This picture was Monday night with the built in aerators, spa fountain and spillover all doing their thing. pH went through the roof though.

Not sure if the deeper water is warmer, but since the pump suction is pulling from the skimmers, I take it the returns are dispersing that cool water pretty well.
To test, I dip my meat thermometer probe about 3" into the water, then into my sample bottle that I collect about elbow deep. So far those have agreed.