Solar Pool Heater

Brent Dowell

Administrator
Staff member
Messages
16,540
Location
Reno NV
Well, I'm probably 95% done, so thought I'd post a pic. Need to pick up a couple of more cans of 'Fusion' plastic spraypaint.

Already had the rack to mount it on. Actually, it used to be about 4 foot longer, but took part of it off. Added a 1 foot extension up top, then painted it all black. It's facing due south.

Basically, just a bunch of PVC all glued up together. 210 feet of 1/2" pipe between two manifolds. I figure the 7 1/2" pipe gives me a decent enough flow rate. That way I can run the filter and the heater on the one circuit.

Use some cheap flat black paint on the rack. Used a couple of cans of fusion plastic spray paint on the tubes. Still need a couple more cans, but I figure this should be a good start.

I've got a bunch of valves rigged up so I can easily shut off the flow to clean the filter, or to send the water through the heater.

Can't use flexible hoses, or sprinker type tubing, because there are some kind of critters around here that like that plastic. I have to splice in repairs to the drip irrigation pretty frequently. Don't really want a hole to pop open while the pump is running and drain the pool...

So physicists, start your engines and debate for me the relative qualities of flow rate, and tubing size versus length.

I'm of the opinion that slower flow rates result in higher output temps, but that it doesn't really matter to the overall rate of temperature increase to the pool.

The more tubing, the better. The thinner the tubing, the better.

The pool temp started at 55 degrees today, which, I believe, is hypothermia inducing! :rolleyes:

We'll see how long it takes for this heater and the solar cover to get the pool to a decent swimming temp. I'd like the pool to be in the low 80's, but I'll still use it in the 70's, if the outdoor temp is warm enough...



valves.jpg

solarpoolheater.jpg
 
Last edited:
Sure looks like it oughtta work, Brent.

As for the flex tubing - around here, the porcupines seem to like chewing on it. Got any of them critters out there?:D:D
 
No porcupines, but plenty of ground squirrels, rats, mice, cottontails, Quail, Chukar, jackrabbits and rattlers :D

Just happy to have not seen any rattlers yet this year! :thumb:
 
Last edited:
I guess you will find out how well it works :thumb:

A friend's dad did a similar thing with black rubber hose up on the roof of their house, two huge coils of rubber hose, and it made a big difference. Also, IIRC he did not use a pump, plain old convection worked..... I think....:huh: :dunno:

Neat idea! :wave:
 
I was wondering along the lines of what Stu mentioned. How hard (or effective) would it be to make one that's pumped by convection?
 
Now you have my interest up! I would love to heat my pool so I could extend my season. Gas heater is just to expensive for me. And just a couple of cool nights and the temp drops like crazy. Ended up closing it early last year due to the cool nights but the days were still hot. So I am anxious to hear how this works out for you.

I studied solar heating during the 70's and 80's when it was a big thing. One trick was to enclose the coils in a box with a glass. That raises the temperatures and heats the water faster and hotter.

It would be really good if you had a way to check the water temp going in and coming out of the collector. Then it would be easy to adjust the flow rate to get the best temp. Not sure how you can do that cheaply or easily though. But too fast and the heat can't transfer to the water but you knew that didn't you? ;)
 
A friend with a solar kiln says it is always 75 degrees warmer behind glass than ambient air temp.
And, like Bob, wondering why you need any heater in the hot,hot, hot Nevada desert. :huh:
 
And, like Bob, wondering why you need any heater in the hot,hot, hot Nevada desert. :huh:
Because of the cool cool nights. Same issue here in Idaho. Around Labor Day the daytime temps can be in the 90's, but the nights are in the 60's. The pool looses heat very quickly under those circumstances.
 
I was wondering along the lines of what Stu mentioned. How hard (or effective) would it be to make one that's pumped by convection?

The actual term is Natural circulation. The Nuclear reactor that I worked in while in the Navy used it to elimate the pumps. We were able to get 60% power from the reactor using it. It relies on the fact that the hot water will go up and the cooler will go down in the system. The formula as to how to calulate the flow rate is bH delta T where the b is a constant based on the flow characteristics of the piping (dia, number and angle of the bends, etc). H is the differance in height between the heat source (the solar collector) and the heat sink (the pool). The heat source must be lower then the sink. Cooler water from the pool will run down hill and force the warmer water up towards the pool. OK enough physics for today.
 
We've been having a very, very cool spring. Warmest temps so far has been 70 at best during the day. It will get very warm in a while, but that only lasts for about 30-50 days.

We have technically a 90 day growing season here...

I do like the idea about putting a cover over it, so I'll try that, even if it's just some visqueen this year.

I had it running yesterday and got the pool temp up from 55 to 62.

Been on the couch all day today, can't really move, but hopefully if we get some sun later this week will get it running again.

I'll be swimmin in 5 days!
 
But too fast and the heat can't transfer to the water but you knew that didn't you? ;)

Yeah, but I still have to keep up the flow rate to keep the filter running, since it does the cleaning and such.... Maybe enclosing it will help with the heat transfer

Cooler water from the pool will run down hill and force the warmer water up towards the pool. OK enough physics for today.

Thats interesting, so if I put the heater lower than the pool, and ran hoses from it, It might just work on its own without the pump. That's an idea worth looking at...
 
I just got out of our pools, feels great. No heater here just a solar blanket. But it's been in the 90's. Now we won't eve need the solar blankets until fall..:D


It's been too cool here to even really think about getting in the pool. I just want to get it revved up so when I'm ready, it's ready..
 
Yeah, but I still have to keep up the flow rate to keep the filter running, since it does the cleaning and such.... Maybe enclosing it will help with the heat transfer

If I am looking at your plumbing correctly you should be able to adjust the valves so that some of the water goes through the heater and some bypasses it? That would keep the total flow the same, just part is diverted and heated by the collector. If not, I would look to see how hard it would be change it so you can.

I opened my pool up today and was looking at the lines. It wouldn't be a huge to deal to add a collector into the circuit. I probably wouldn't do anything this year but you have me thinking ahead. Maybe I can stumble on some cheap copper tubing.
 
Yep, I've got it setup to be able to totally shut off the pool, or the heater. I could easily slow down the flow based on how I adjust the valves. It actually works pretty well. I'm liking the idea of boxing in the tubes, I think that should work pretty well, adn help to extend my season, if we ever get any sun here this year!
 
Top