I understand how the channeled black mats are designed to work. The radiant light energy from the sun falls upon the black mat, heating it...then the water comes into contact with the black plastic & absorbs the heat...yada yada...
I also understand how, if water is channeled through the mat at night...assuming the air temperature is cooler than the water...the mats can be used to cool a pool.
Then this stands to reason as well...right? :
If my pool water is cold (right now at 70 degrees) and the sun is going down (no longer shining on the mats)...but...the ambient air temperature is still over 70 (and right now it's 83)....then I'm still picking up heat through the mats.
Granted...at a reduced level...but I'm still heating the pool through the transfer of ambient air heat through the mat.
And allowing the pump to channel water through the solar heater, even while in shadow...is raising my pool temps (albeit slowly).
Any flaw in my analysis here? Thanks...