Okay, well I am still trying to figure out how I could (without taking up tons of space, or spending lots) raise my pool around a degree per 24 hours. In my situation, that would be enough for me to feel it was worth it.
Especially since my hot tub is 1/60th the volume of the pool and 1 degree per day for the pool = SO much free heat for the hot tub.
I'll accept that I might have to go with commercial solar panels, but if so, I still am hopeful that I could use the solar pump I already have here, that I don't have to hook into existing pipes, that it could be simple enough that I can install it, not have to put on roof, etc. Also if I am going to go with commercial panels, I may have to wait until the spring to do it at all.
So, having done more research, and still considering the DIY route:
Yes, for my pool size, I probably actually need 180,000-190,000 BTU to go up a degree. (Pool is around 22500 gallons, maybe a bit more.)
Many people on that webpage are claiming they are getting 5100-7100 BTUs per hour output from their 500 ft 1/2" coils. And people with 250 ft coils are claiming about half as much. I would love to get 7100 BTU/hr.
I guess they could be wrong, but it seems pretty strange for so many DIY minded people to be wrong. When they are testing their working running coils/pumps. They're definitely wrong? I mean, this is a pretty good design and there even exists the company called suncoil that professionally sells a similar design. Maybe it's a bunch more efficient than usual solar panels?
Plus some people are claiming the water comes out at like 100 something degrees, or that their pool got well into the 90's and was too hot, their DIY heater was TOO good and they had to make it run less than the full day. Many of them had smaller pools but many don't. Also the ones with bigger pools were doing 500' not 200'.
Another thing my friend smartly pointed out is that with my DIY method, my intake hose can be 3.5 feet down in my pool, or even lower if I wish. So I am able to exchange colder water than if the water was just getting sucked into the usual intake pipe from my pool... I guess. Plus, especially if I have my warm output water going into the shallow end, I know water mixes fast but I think it's kind of like you can ignore the bottom half of the deep end of my pool. That part can stay colder, and then it's like my pool is smaller in a way.
Or in other words, basically I mean, it's like the same concept as with a solar cover. Someone might buy one and say wow, it raised my pool 6 degrees. They don't mean the entire pool water average. They mean the top 2-3 feet that they can feel and where their thermometer is. If you did the cold math, you'd be telling them no, you only raised your pool temp 2 degrees, but in reality they are happy since it's like 6 degrees.
Some DIY people are using slow pumps, others pretty fast pumps... maybe they are all slower than the usual pool filter system pump, and maybe it makes the DIY more efficient?
That is a VERY good point that some of the DIYers are getting like a placebo effect, including heat that they gained from their cover or the natural sun's rays, etc... but I tend to think that most of them are measuring things fairly well, I mean I don't think they are off by 500%, but maybe off by 20-50%.
Also, say my pool temp doesn't feel 1-3+ degrees warmer after 1-3+ days. At least I might like that I could go over near the output hose and I could stand near it and it would be warmer.
Anyway, I know that I may still be missing things here. And no, I don't want to defend it even if it's wrong, and go and waste my time/energy/money on this if it's not going to get a certain level of results. I just have a hard time believing it won't given that many other people seem happy with theirs or seem to think that their logic is sound, etc.
... To the person who was going to coat the tubes with varnish: I just found a webpage where a guy tested it with his collector (not a coil style though) and said it helped very little. He did say it was probably little because of the air temp being warm though (air temp was similar to pool water temp before heating).
Especially since my hot tub is 1/60th the volume of the pool and 1 degree per day for the pool = SO much free heat for the hot tub.
I'll accept that I might have to go with commercial solar panels, but if so, I still am hopeful that I could use the solar pump I already have here, that I don't have to hook into existing pipes, that it could be simple enough that I can install it, not have to put on roof, etc. Also if I am going to go with commercial panels, I may have to wait until the spring to do it at all.
So, having done more research, and still considering the DIY route:
Yes, for my pool size, I probably actually need 180,000-190,000 BTU to go up a degree. (Pool is around 22500 gallons, maybe a bit more.)
Many people on that webpage are claiming they are getting 5100-7100 BTUs per hour output from their 500 ft 1/2" coils. And people with 250 ft coils are claiming about half as much. I would love to get 7100 BTU/hr.
I guess they could be wrong, but it seems pretty strange for so many DIY minded people to be wrong. When they are testing their working running coils/pumps. They're definitely wrong? I mean, this is a pretty good design and there even exists the company called suncoil that professionally sells a similar design. Maybe it's a bunch more efficient than usual solar panels?
Plus some people are claiming the water comes out at like 100 something degrees, or that their pool got well into the 90's and was too hot, their DIY heater was TOO good and they had to make it run less than the full day. Many of them had smaller pools but many don't. Also the ones with bigger pools were doing 500' not 200'.
Another thing my friend smartly pointed out is that with my DIY method, my intake hose can be 3.5 feet down in my pool, or even lower if I wish. So I am able to exchange colder water than if the water was just getting sucked into the usual intake pipe from my pool... I guess. Plus, especially if I have my warm output water going into the shallow end, I know water mixes fast but I think it's kind of like you can ignore the bottom half of the deep end of my pool. That part can stay colder, and then it's like my pool is smaller in a way.
Or in other words, basically I mean, it's like the same concept as with a solar cover. Someone might buy one and say wow, it raised my pool 6 degrees. They don't mean the entire pool water average. They mean the top 2-3 feet that they can feel and where their thermometer is. If you did the cold math, you'd be telling them no, you only raised your pool temp 2 degrees, but in reality they are happy since it's like 6 degrees.
Some DIY people are using slow pumps, others pretty fast pumps... maybe they are all slower than the usual pool filter system pump, and maybe it makes the DIY more efficient?
That is a VERY good point that some of the DIYers are getting like a placebo effect, including heat that they gained from their cover or the natural sun's rays, etc... but I tend to think that most of them are measuring things fairly well, I mean I don't think they are off by 500%, but maybe off by 20-50%.
Also, say my pool temp doesn't feel 1-3+ degrees warmer after 1-3+ days. At least I might like that I could go over near the output hose and I could stand near it and it would be warmer.
Anyway, I know that I may still be missing things here. And no, I don't want to defend it even if it's wrong, and go and waste my time/energy/money on this if it's not going to get a certain level of results. I just have a hard time believing it won't given that many other people seem happy with theirs or seem to think that their logic is sound, etc.
... To the person who was going to coat the tubes with varnish: I just found a webpage where a guy tested it with his collector (not a coil style though) and said it helped very little. He did say it was probably little because of the air temp being warm though (air temp was similar to pool water temp before heating).
