Pool is too HOT

[fortunate]

Results are in, yesterday and today:

6pm, 91F pool, 84F ambient
6pm, 87F pool, 89F ambient

I know my air temps are correct, but the water temps, I'm not sure. The pool equipment seems wrong sometimes. I also have a infrared thermometer, but I'm not sure how accurate that is for shooting into the water. Maybe it's measuring the plaster temp, maybe that's close enough.

Today seemed like less sun, more overcast, and it rained. However I have a Tempest weather station (you can see it in the pic on the little table next to the pool) and it shows today as being hotter on average but with a lower max air temp. I guess the 2 days are roughly equivalent.

So, something like 4 degrees lower for running the WaterBUG for 24 hours. I did a 5km run and jumped in the pool and I can tell you the fountain made a HUGE difference! It's about as warm as it can be and still be considered refreshing, but it was great. So much better than the "warm bathtub" feeling it was before.

I'll hold off on a heat pump and see how this goes. I don't think I'll run it every day. I'll try overnight the day before I expect someone wants to swim, eg based on my running schedule.

Thanks again to tcross04 and everyone else for their input!

 

[PoolBrews]

That is about what I experienced when using this method. My issue was that I had to run my pump too much, and there was considerable water loss due to evaporation... plus I still had no shade when it was 100 out. I know it's a bit more work to install shade sails, but they make a far bigger difference in water temps, and cost nothing once installed.

 

[fortunate]

Thanks, I do think the shade sails are pretty great. This isn't my forever home, so I'm not sure how much effort I want to spend. It's 4" concrete with astroturf all around my pool, so I'd need to break that to install posts. I'll give it some more thought!

I wonder if the evaporation with the WaterBUG is less than with the Glacier?

 

[duraleigh]

Poking the bear here a bit but I hope it's a conversation worth having.

I am convinced an aerator is more effective during the day than at night.

I believe that because evaporation occurs most rapidly when the temp/dew point is as wide as possible.........that occurs during the daytime and not at night when the temp dewpoint spread can be very close together.

The coolness of the air doesn't have much to do with evaporation but relative humidity (greatest at night) causes the process to release the most heat. I no longer have a pool where I can experiment but I really think daytime evaporation will supply the coolest water back to the pool.

So, if that is true, then run times of around 9:00 AM to 7:00 PM should be most effective

 

[fortunate]

FWIW, ChatGPT suggests that while RH does make for more rapid evaporation, the larger temperature difference at night makes a bigger difference. You can see the detailed answer here:
https://chat.openai.com/share/d34e5b24-e110-4bdc-b276-90389d1b464d

 

[aztony]

I'm guessing the Glacier chiller wouldn't work so well here in AZ where the humidity is so low.

 

[fortunate]

Low humidity is good:

Lower humidity promotes faster evaporation, and evaporation removes heat from the water.

If you have low humidity and low temps at night, that's perfect. ChatGPT's theory is that temperature makes more difference than humidity. Even with high (eg 90%) humidity at night, the lower air temperature is good for an evaporative cooler.

 

[JoyfulNoise]

I'm guessing the Glacier chiller wouldn't work so well here in AZ where the humidity is so low.

It’s essentially a swamp cooler. There are LOTS of swamp coolers in AZ. As anyone that owns an old desert home knows, swamp coolers work great right up until the monsoon season when the rain and humidity kick in. Once the monsoons hit, the swamp cooler is nothing more than a giant worthless fan blowing warm air. Once the monsoons end, the swamp coolers work again but, by that time, the day time temps are cooler.

A Glacier cooler would work here in AZ during the overnight hours when the air is a bit cooler and the humidity a little lower. So if you run the Glacier overnight, you can easily cool the pool about 6-10°F overnight.

The downside is you will evaporate a lot of pool water in the process and thus add back a lot of water as well. With our calcium/mineral rich water, that’s going to lead to a lot of build up on the internal cooler fins. Again, as anyone with a swamp cooler here knows, the mineral rich water pretty much destroys the wicking media inside the cooler and you have to change cooler pads at least annually. Old pads will also get musty and mildly smelling if you don’t sanitize the water properly. That’s not a big deal with a Glacier because the water is sanitized already but scale build up will be an issue.