attempt to use the "heat rises" theory to heat pool naturally

[iam4iam]

In years past, I have contemplated numerous methods to heat my pool without an actual heater. i guess I don't really mean heat the pool, but help it maintain maximum temperature, thereby extending swim season. Regardless of semantics, here is what I have done.

I created pvc extensions that divert water from the returns to the bottom of the pool, assuming that water at the surface of the pool is warmer that the water at the bottom. My theory is that when the pump is running, I am transferring some heat from the water surface to the bottom of the pool, and that heat will then transfer more quickly upward than it would have otherwise transferred downward. I also assume that this process is most efficient with my solar cover on.

Now to the over-analysis. I have also theorized that the most effective way to distribute my 4-hours of pump run time would be to break it up into 4 1-hour segments with one hour between each segment to give the sun time to heat the water just beneath the solar cover before transferring that heat to the bottom of the pool.

I keep a spreadsheet for all of my pool stats, but since ultimately the water temperature is dependent on the weather, I cannot really obtain much empirical evidence that the system is working, because I cannot control the experiment. That said, does it at least make sense in theory?

 

[woodyp]

I'm thinking that's a lot of OVER thinking if you've already got a solar cover on it! Good luck!

 

[Joshii]

You need to build an identical pool right next to this one and have the returns set up the normal way. Then you can have a control. Write us back when you have results.

 

[Pool_Medic]

Look up Venturi return fittings. They do exactly what you are trying to do.

Want a cheap heating source. Buy a clear solar blanket, it protects against the cooling effect of wind but also allows the suns rays to penetrate the water and heat it up.

 

[woodyp]

You need to build an identical pool right next to this one and have the returns set up the normal way. Then you can have a control. Write us back when you have results.

I'm guessing Joshii is willing to fund that little experiment!

 

[Yev]

Buy a clear solar blanket, it protects against the cooling effect of wind but also allows the suns rays to penetrate the water and heat it up.

Not exactly. While being better than a Blue cover, even a clear cover will absorb some of the sun's energy. This is just a property of plastics such as PE, nothing you can do about it. 100% without dispute, more sun rays penetrate the water without a clear cover than with a clear cover.

 

[splashpad]

I created pvc extensions that divert water from the returns to the bottom of the pool, assuming that water at the surface of the pool is warmer that the water at the bottom. My theory is that when the pump is running, I am transferring some heat from the water surface to the bottom of the pool, and that heat will then transfer more quickly upward than it would have otherwise transferred downward. I also assume that this process is most efficient with my solar cover on.

As long as you are stirring up the deep end and not putting filtered water straight back into the filter, sounds great to me! Yes to the solar cover.

Now to the over-analysis. I have also theorized that the most effective way to distribute my 4-hours of pump run time would be to break it up into 4 1-hour segments with one hour between each segment to give the sun time to heat the water just beneath the solar cover before transferring that heat to the bottom of the pool.

I love to over analyze. I disagree slightly, I theorize running the 4hrs during the most direct sunlight time of day, would provide the most substantial results.

I keep a spreadsheet for all of my pool stats, but since ultimately the water temperature is dependent on the weather, I cannot really obtain much empirical evidence that the system is working, because I cannot control the experiment. That said, does it at least make sense in theory?

I think so =)) And it doesn't hurt anything far as I can tell, except you should have great turnover rates!

 

[iam4iam]

You need to build an identical pool right next to this one and have the returns set up the normal way. Then you can have a control. Write us back when you have results.

Thank you for your support, Splashpad!

 

[tstex]

Since it's your pool and your time, you can spend it anyway you wish...But, for the amt of effort on what you would gain, I believe it's a low ROI on your time proportional to effort exerted.

Our pool temp's were 62-65 degrees about 2 weeks ago [clouds and a few last cool fronts]. Now that we have a high pressure cell upon us, no clouds, our pool temps have gone crazy...almost 80 degrees now.

The sun, or lack thereof, is the greatest source for heating your pool w out human intervention. If you want to increase the pools temp, do everything you can to increase the direct sun rays that hit it [trim tree branches or remove other obstructions]. The other obvious way to increase your pool temps are human intervention: heater turned on, install solar panels, etc.

Your best effort, when the sun does heat up your pool, is to continue man made efforts to keep is warm when it is already near a temp you desire. It's the initial heating that takes the most energy to take it from a lower temp to a higher temp, vs keeping it at a temp that is already desired.

Read paragraph's 3 & 4. good luck

Heat Capacity of Water

 

[Stargate_to_earth]

If you want to overthink it, here's some math for you.

Sounds like you would just be mixing the water more. I dont think that it would have the desired effect for you.

Pool temperature losses are based on a few things, Evaporation, Convective/convective heat transfer to the walls and ground (depending on the air and ground temps).

If the ground temp is lower than the pool temp, more flow at the points of contact with the ground is going to cause better heat transfer there (heat flowing from warmer to colder places).

It may be possible that mixing the water that is touching the solar cover may help, but only with the heat that is being captured by the solar cover itself, not with the idea that the solar cover is insulating the pool.

Now on that, if it is colder outside then your pool temps do not run your pump at night. Better flow=better heat transfer.

If you wanted to get industrious you could try to setup a natural circulation solar heater if you have an area with direct sunlight that is lower in elevation than your pool. See link above for the math. The general idea is that colder more dense water sinks, while warmer water rises. If you can get enough of a height difference, temperature difference, and minimize restriction to flow, you might be able to have a super simple cheap completely free (you dont have to run the pump to get the heating) solar heater.

This could require something as simple as garden hosing (probably too much flow resistance), or a good bit of large diameter PVC...

 

[Stargate_to_earth]

Didn't mean to kill the thread, no comments on my post

 

[woodyp]

I ordered one of those Venturi return fittings to experiment with.

 

[iam4iam]

Didn't mean to kill the thread, no comments on my post

Thought I replied. I remember writing a reply anyway. Maybe I forgot to post and I was timed out? Anyway, the math lost me on the second page. No matter. Now I have a new venture (not Venturi). I thought about trying out those Venturi returns, but too much for me to spend for an experiment. I know, I spent more than that on the PVC I used to do what I did. Oh well.