Solar setup

[Switched]

All,
I’ve got a rooftop solar setup (heliocol) with a single pump doing the heavy lifting. I have a valve that either sends it to the roof solar or bypassing solar and send the pumped water direct to the pool. Today is the first time I sent it to the roof.

Under normal situations and everyday pumping should it:
1) always go to the roof 100% which then goes to the chlorinator and then pool from the roof
2) have the valve setup to give a portion to the pool direct, and also some to the solar as well (ie set valve to 45 degrees) please indicate at what percentage for the valve) - I ask this as it might be restricting flow on the solar setup and restriction of water means less flow and hotter water?
3) only use solar setup when I plan to be swimming. If so, what percentage should the valve be set as per above.

This is just my observation, with the pump going to solar 100% on a cloudy overcast 25 degree Celsius’s day for 2 hours, I notice the pool went from 23.8 to 24.8 degrees on the return to the pool.
Does all that sound normal?

Secondly I also have a pool cover. as we approach end of summer, is there any need to send it to the solar if I dont plan to swim, well at least alot less frequently?

 

[YonnyPiscinas]

Hi Switched.

How many meters of panels do you have and what is the surface area of your pool?
I installed solar panels/collectors about 4 months ago now just before the start of summer here in Uruguay.
First I would say the heat gained through the panels depends on factors such as the strength of the rays, wind and whether or not you have a pool cover. If you are not careful sometimes you can end up with the panels cooling the water on a cooler cloudy day but your gain of 1c in 2 hours appears very very good. I do not get that even with 110% coverage and full sun. But maybe you are gaining this due to your pool being cold at the beginning. Mine is hot so the gain is less I guess.
I got an infrared temp gun to measure the heat gain through the inlet and outlet pipe of the panels too to gauge the heat gain. 0.3-1.3c is fine with a good flow. If you notice there is no heat gain or even cooling on a cloudy day you'll realize when to switch them on or not.

I took the guessing out of the temperature on the roof and installed a temp probe on the roof that controls the pump. I only have manual valves that control the flow to the panels.
The device that controls the pump is a sonoff TH16 with waterproof probe.
I set it at about 33c-40c at this moment in the season (this will all depend on your conditions/time of year etc and current temp of your pool - mine is set high because my pool is hot and don't want the water flowing and cooling) so when the sun is strong enough (cloudy or sunny) it will turn on the pump. I open the valves each morning if I know the weather is going to be good. On a rainy day I have the valves to the panels closed and water bypasses them just to filter the water.
Its either 100% through the panels or bypass.

My pool at the moment stays between 31.5 - 35c. I have a cover on every night and some of the time during the day.
The cover at night is essential to maintain the heat gained otherwise we lose everything and start from scratch again in the morning.


Took a good week or so at the beginning to get the pool up to a decent temp though. Be patient.
Take into account evaporation counts for a big loss in heat so a cover is essential if you want to keep that heat in.

 

[Switched]

Hi Switched.

How many meters of panels do you have and what is the surface area of your pool?

My pool size is 8m x 5m kidney shaped.
My solar setup looking on google earth is 3.5m x 6m looking direct down, suspect it might be slightly bigger as there is a pitch on the roof.


Maybe it was more like 3 hours or so, pretty sure it turned it on in the early afternoon around 2pm and checked about 530pm or so.
Oh - I am a bit of a home automation nerd - I run home assistant at home although still need to fire it up since I moved in recently. My setup has no dedicated pump, nor any temperature probe at all, not even in the pool. I hope to change that but need to work out how best to run a temp probe for the pool? Any suggestions?

Thanks - you've given me some things to think of as I try and automate this (when I have some time).

 

[YonnyPiscinas]

My pool size is 8m x 5m kidney shaped.
My solar setup looking on google earth is 3.5m x 6m looking direct down, suspect it might be slightly bigger as there is a pitch on the roof.


Maybe it was more like 3 hours or so, pretty sure it turned it on in the early afternoon around 2pm and checked about 530pm or so.
Oh - I am a bit of a home automation nerd - I run home assistant at home although still need to fire it up since I moved in recently. My setup has no dedicated pump, nor any temperature probe at all, not even in the pool. I hope to change that but need to work out how best to run a temp probe for the pool? Any suggestions?

Thanks - you've given me some things to think of as I try and automate this (when I have some time).

ah me too. Got a bunch of broadlink/sonoff devices etc. alexa/googlehome/IFTTT doing all sorts of automation tricks including cameras and movement sensors.

I have 2 sonoff TH16 devices. These were cheap and work very well for my set up. They are switches up to 16amps, fine for my one speed 0.5HP pump and SWG. I use this pump for everything, no dedicated pump.
One with a probe in the pool measuring the temp.
Also another with a probe next to the panels on the roof.
My neighbour does have a dedicated pump for his panels so useful as he does not need to open and close valves.


So the main switch for the pump goes through the sonoff TH16 and is used to switch the pump on and off when you want. manually from your phone, scheduled or auto within a temperature range set on the app.
Check it out on google.
The sensor that comes with the TH16 has a short cable. You can buy a sonoff extension 5m but I just soldered in a cat5 cable extension using 3 of the wires. Works fine and accuracy is the same. New software version for the TH16 temp probe shows increments of 0.1c.

Would be even better if I could install actuators on the valves but I can't get hold of them here. Maybe next trip to USA.

Cheers

 

[Switched]

Thanks for your help.

With regards to the roof sensor, I was thinking a ESP8266 with a temp prob? I have some UV protected Cat5 cable and might run this on the roof but not sure if the DS18B20 is capable as an external sensor as yet. Where I can mount the ESP8266 is under my pergola/patio and run the cable over the roof to where my panels are.

Unfortunately (or fortunately) in my setup, my SWG controller, has a timer setup in in, that turns the pump on at the SWG % as well during the timer events. I may leave this until it breaks and get some serious HA setup going with it. I even have a few TH16 lying around as well
Maybe long term, a better pump as primary setup, and use existing Onga pump to control the solar setup.

How do you do your temperature probe in the pool? This is probably my first challenge. I was out there today and I actually have some old PVC tubes in my pool pump area that I can see water looking down the hole, but unsure where they go (they were an old setup of solar or something). I Might put down a 'snake' and see if I see the snake pop out of of the pool returns - maybe I can simply just feed a DS18B20 down on of these pipes after monitoring the temperature to see if it matches in temperature.

Agree on the actuators - having a full setup would be great. These can be had from the US: https://www.amazon.com/Hayward-GVA-24-Valve-Actuator-Replacement/dp/B002JJZ0NM. My pool has a spa inbuilt that is separate. I would be interested to see what temps my solar heats just my spa only in winter.

 

[YonnyPiscinas]

Thanks for your help.

With regards to the roof sensor, I was thinking a ESP8266 with a temp prob? I have some UV protected Cat5 cable and might run this on the roof but not sure if the DS18B20 is capable as an external sensor as yet. Where I can mount the ESP8266 is under my pergola/patio and run the cable over the roof to where my panels are.

Unfortunately (or fortunately) in my setup, my SWG controller, has a timer setup in in, that turns the pump on at the SWG % as well during the timer events. I may leave this until it breaks and get some serious HA setup going with it. I even have a few TH16 lying around as well
Maybe long term, a better pump as primary setup, and use existing Onga pump to control the solar setup.

How do you do your temperature probe in the pool? This is probably my first challenge. I was out there today and I actually have some old PVC tubes in my pool pump area that I can see water looking down the hole, but unsure where they go (they were an old setup of solar or something). I Might put down a 'snake' and see if I see the snake pop out of of the pool returns - maybe I can simply just feed a DS18B20 down on of these pipes after monitoring the temperature to see if it matches in temperature.

Agree on the actuators - having a full setup would be great. These can be had from the US: https://www.amazon.com/Hayward-GVA-24-Valve-Actuator-Replacement/dp/B002JJZ0NM. My pool has a spa inbuilt that is separate. I would be interested to see what temps my solar heats just my spa only in winter.

I see you're a step ahead. Arduino is a good route to take. I just haven't had the time to do that. The TH16 was a fast and simple way of controlling my pump. The SWG is set to turn on with the pump.

I don't have the ideal set up with the pool probe. I have some white plastic cable tidy casing (the white casing you use to cover cables on walls inside the house) used to go across a narrow section of the pool border into the pool. Not ideal but if you have an existing pipe you can feed it into even better. Thought about using the skimmer but then the temp is not consistent and will drop when the flow stops.

Thought about installing probes into the piping but then this will only read the temp when the water is flowing.

Also good thing about the sonoff sensor is that it is waterproof and rustproof. Have the TH16 next to my main pump fusebox and then the cable running up to the roof, luckily it is above the pump (panels are on a pergola)

 

[Switched]

All - thanks for the help this far. Came home from work and my pool is now sitting at 26.5 degrees pool pump runs for 7 hours a day and temperature was 28 degrees today. Next two days are 31 degrees so will be interesting to see the temperature of the water these next couple of days

 

[YonnyPiscinas]

All - thanks for the help this far. Came home from work and my pool is now sitting at 26.5 degrees pool pump runs for 7 hours a day and temperature was 28 degrees today. Next two days are 31 degrees so will be interesting to see the temperature of the water these next couple of days

yes just keep it running while the rays are strong - do you have a cover? What are your night time temps? Is the pool in a sheltered area? I find without the cover I have to top the water up frequently due to a lot of evaporation. 70% heat is removed through evaporation.

 

[YonnyPiscinas]

Our summer in Uruguay is beginning to slow down, unfortunately. The exception today 34c so taking advantage to run the panels as long as poss. Low to mid 20's next week. boooo. sun getting lower.

Pool temp down to 30.9c now. cry! (was awesome at 35c) Maybe will gain 1.5c today if it doesn't cloud over. But gains are getting smaller each day and losses greater even with 2 covers on!! lol

I guess this is where a heat pump comes into action to get it back up to 32/33.
Maybe next year as finances now do not allow as we're spending money on house central heating upgrades.

 

[Switched]

Nice! I had it at 28 degrees and was a nice swim, unfortunately has been a little cold so turned solar off for a little bit.
Still thinking a lot about the solar automations, roof probe and water pool probe and automation to turn the valve to adjust flow.
I really don’t have a good way to get pool temperature just yet - I’ve seen some temp probes on the pvc piping so expect that would be reliable only when the pump is on?