Just a heads up, my setup is kinda ghetto. I was tired of waiting for the hydro kit for the S21 Pro, so I’m trying an air-based method I saw online. Someone heated a bathtub with an S9, so why not? Lots of heat will escape through the ducting but I’m hoping at least 20% makes it to the pool. Total cost was around 50 bucks. Can't figure out how to post pics though.
The ducting you have at the miner isn't great. You should really consider 3D printing or buying a proper shroud. I found an example online (not sure if it's legit), but it shows how to do it right. With a proper setup, almost all the heat would go into the duct, plus heat from the PSU would help too. You might wanna think about insulation as well.
Just so you know, if you switch to a hydro setup, don’t pump pool water directly through the miner. The chlorine and pH stuff will wreck the aluminum cooling parts. You need a two-stage system with a stainless steel heat exchanger. One side for pool water, the other for DI water running through the miner.
I saw someone use a stainless steel hose for this. They coiled it in the pool and covered the part outside with fiberglass. So it goes miner > hot water pump > fiberglass on the hose > most of the hose in the pool > cooler water back to miner. 100 feet of the hose should work just fine and won’t cost much.
I’m always shocked that people risk their expensive miners like this. You really need some temp control in the setup. Miners like to run at about 40-50C. If the temps swing too much, it can make them unstable, plus stress the solder connections. Also, braided hoses have a liner that isn’t great for heat transfer. Better off going with a regular thin-walled hose.