DIY coiled hose solar heater setup details? or Solar Panels and Delta T output?

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theskyisthelimit99

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Jun 28, 2016
426
Pittsburgh, pa
I've seen pictures online of many who have done the whole wrapped up with zip ties hose setups to heat their pools..

Currently i'm testing those pre-fab solar domes.. im pretty sure as i figured, they will be worthless.. and i was considering putting solar panels on my garage roof about 30-40 feet away as another option..

But it sounds as if a 4x8 sectioned off area with two coils of these "hoses" might do the trick quite well (in parallel) and use the existing diverter kit i have right now in the other thread for the domes?

Issue is.. i cant find anyone with a good build log (unless i'm just missing it or not searching for the right keywords)..

I'd like to know the following:

-type of hose used
-how to interface with my pvc connections (1.5")
-any worries of degradation on the hoses over time and then leaking?
-typical temperature at the output using 1 or 2 coils? (one person showed 150F, this is scolding!, not so great? or just turn off when people in the pool)
-best arrangement in yard? (guessing a 4x8 2x4 framed area, maybe tilted up a little towards the south, some sort of base to lay them on, maybe an X of 2x4's)?
-what type of plastic goes over it and the black material under the hose?
-i'm thinking i'd put a 3 foot fence (chicken wire) around it for safety (young kids)

*hoping to keep this cost at 150 or less if possible (IE: solar panels on the roof would run $280 + cost for more pvc)
*i'm in southwest PA.. so hoping to find some comparibles.. ie: april weather when its 70F and sunny, will the hose heat up to enough to raise the temp in the pool by much? (almost assume that a solar panel array would heat up better on a 70F day than this coiled hose)?

Also.. certainly high heat is not a good thermodynamic goal here.. rather, heat a lot of water a little instead.. not sure the wrapped hose route is efficient.. unless 50 people chime in and say their water jumped from 58 to 69 over a week with 70F sunshine each day?

The alternative for now, i may just get one of the solar panel kits and lay the 80sq feet (more ideal 160sq feet) in the yard (directly on the grass) in place of the domes/hose tests and see how it fares, then if it works well enough, move to the roof, or perhaps the roof gives better radiational heating and the test would be not as accurate.

Thanks for any info
 
Re: DIY coiled hose solar heater setup details? Typical temps and increases?

Not sure on what the answer is. I looked into it last year since our pool barely hit 70 most of the season. Some have said it raised their pool by as much as 20 degrees and others that said it really wont do any good. If I had the extra coin I would give it a go.
 
Re: DIY coiled hose solar heater setup details? Typical temps and increases?

Solar heating is all about square foot exposure to the Sun. It is virtually impossible to build a DIY solution with black coil pipe for cheaper than you can buy the prefab panels. You also want high flow rates through your solar heating set up. Having two very long Loops of black pipe would be very inefficient as the flow rate would be restricted.
 
Re: DIY coiled hose solar heater setup details? Typical temps and increases?

jblizzle said:
Solar heating is all about square foot exposure to the Sun. It is virtually impossible to build a DIY solution with black coil pipe for cheaper than you can buy the prefab panels. You also want high flow rates through your solar heating set up. Having two very long Loops of black pipe would be very inefficient as the flow rate would be restricted.
Click to expand...

You just gotta increase your pump pressure. Same with elevation. The higher you pump the water the more pressure you need to get the target gpm you are looking for. Tube size and friction suck.
 
Re: DIY coiled hose solar heater setup details? Typical temps and increases?

But you can't just increase the pump pressure if you don't have a variable speed pump that is not already at Max Speed
 
Re: DIY coiled hose solar heater setup details? Typical temps and increases?

That is also increase the pressure in the black pipes and potentially lead to failure.

Bottom line, trying to use black irrigation pipe or similar, is not going to be as efficient and is going to cost more that just using solar panels designed for the purpose.

When I moved into my house the previous owner tried this on my roof. After a 2 years I pulled all 2500' (1/2 a mile!!!) of 3/4" black poly off the roof as I was sick of the constant leaks and not getting as much heat as I wanted. IIRC that was about 150 sqft if it was laid out properly (it was not). I now have 500 sqft of solar panels and have 80 degree water in February.
 
Re: DIY coiled hose solar heater setup details? Typical temps and increases?

At the end of the day you can't beat the laws of thermodynamics and physics. You will get "some" heat from black irigation pipe. You will not get as much heat as you would from the same amount of money invested in commercially produced panels. It really does come down to the amount of effective square feet of surface you have exposed to the sun. You need a "flat" area to absorb as much heat as possible which is why the tubes in panels are so small and there are so many of them.

You can get 80sqft of Fafco solar panels on Amazon for 230 dollars. If you can come up with a way to DIY that price I'd come to your home and shake your hand. Oh and you need to maintain the flow rate of 5gpm per 40 sqft too.
 
Re: DIY coiled hose solar heater setup details? Typical temps and increases?

CJadamec said:
At the end of the day you can't beat the laws of thermodynamics and physics. You will get "some" heat from black irigation pipe. You will not get as much heat as you would from the same amount of money invested in commercially produced panels. It really does come down to the amount of effective square feet of surface you have exposed to the sun. You need a "flat" area to absorb as much heat as possible which is why the tubes in panels are so small and there are so many of them.

You can get 80sqft of Fafco solar panels on Amazon for 230 dollars. If you can come up with a way to DIY that price I'd come to your home and shake your hand. Oh and you need to maintain the flow rate of 5gpm per 40 sqft too.
Click to expand...
Yeah the more i investigate, the more i'm leaning towards one of those solutions off amazon.. I guess $460 for 160 square feet.. Question is.. fafco or SmartPool varieties.. or does it matter.. is there a way with a diverter / bypass to tell the gpm flow rate.. for instance i have been testing two solar domes just to see how they (dont fare) and i'm using a diverter to slow it down.. the gauge on the end of the diverter is reading 12psi now with my new 1.5hp pool pump, it was reading 1.5 psi on the old intex 0.5 hp pool pump.. my haywood is reading 20psi overall.. I'm thinking i'd be better off just using a separate low rate pump, assuming i could have it external and attach to the extra unused suction port on my pool.. meanwhile to test the panels i'd lay them flat in the yard for now as a test.. i know 45 degree facing south is best, but i figure i should get some indication of their success.. then move them either to the garage roof (which faces west) or build an 8 x 20 wood structure to hold them at 45 in the yard (less ideal)
 
Re: DIY coiled hose solar heater setup details? Typical temps and increases?

Smart pool uses fafco panels.
A diverter will make the system function and set your flow rate through the panels but you will see the best performance if you get a solar controller. Either Hayward goldline or pentair suntouch are your best bet.
 

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Re: DIY coiled hose solar heater setup details? Typical temps and increases?

CJadamec said:
Smart pool uses fafco panels.
A diverter will make the system function and set your flow rate through the panels but you will see the best performance if you get a solar controller. Either Hayward goldline or pentair suntouch are your best bet.
Click to expand...
Yeah i had seen a few of those solar controllers.. around $250 i think.. however, i thought maybe if i use a separate smaller pump, i could put that on a timer and only have it on during the daylight hours.. vs using one pump for everything.. at least for this first year of testing.. then maybe next year go more automated.. i've seen alot that mention the separate pump, some show it inside the pool, but ideally id want that outside, unless the majority just use a single pump for everything (unsure which model/type pump to get, guessing something in the 600-900 GPH range )
 
Re: DIY coiled hose solar heater setup details? Typical temps and increases?

Personally I would stick with a single pump, then only run it in the day like you suggested for the secondary pump. But, whay happens if the clouds roll in or a storm? Not having it automated can cause you to lose a lot of heat if running solar when there is no heat available. Keep that in mind.
 
Re: DIY coiled hose solar heater setup details? Typical temps and increases?

Last year threw together a DIY panel as a test using poly irrigation tubing for our small AGP (~1700gal). End result: $100 total invested and it made hot water.

In terms of efficiency for the space, flow and area it took up--I have no comparison to a commercial system. I don't think it's been mentioned but solar is only practical if you have a way of keeping the heat in the pool. I ended up using our solar cover combined with foam pads floating on top to insulate at night and minimize evaporation. During the cool nights of September the pool would only drop to 70ish degrees. Without the covers it was chilly in the AM!

The setup involved a diverter setup sending water from the pool inlet to the solar array which consisted of two 100' coils of 1/2" poly pipe in parallel. This was very small diameter which reduced the flow a lot and the diverter was set to near full solar flow. If I opt to do this again, there will be at least another two coils to increase the flow through the system. On the hot return to the pool we would see anywhere from a 2-6 degree gain. I measured the flow through the panels and the best I could get at the time was about 2.2gpm (132gph). I worked out the math and this was an average of 2200BTU output on a sunny day from the 4'x8' footprint.

The end result was our small "junior" pool was swimmable until early October (unheard of for Canada!!). My last dip was at 72 degrees on the Thanksgiving weekend which is the second weekend of October up here.

What I would change:

Pool location. Last year we had the little intex setup in a convenient spot for power access, but that meant shade through the hottest part of the day. We effectively lost passive solar gain because of that. We are moving the tub to better location this spring.

Increase flow through the system. Increasing the diameter of the solar coils or possibly adding more of them.

Possibly adding in a secondary pump just for the solar system and losing the diverter setup.

Lessons learned: Keep the heat in! Before I was using the cover on the pool, we'd often lose the entire solar gain from the previous day. Especially as the nights got cooler.

If this was intended to be a permanent setup for a larger pool, I'd have to look at the cost investment/BTU of a commercial system. Bottom line is if max efficiency is required, there are better systems out there. For just making warm water, it can be done inexpensively.

-Ashton


Sent from my iPad using Tapatalk
 
Re: DIY coiled hose solar heater setup details? Typical temps and increases?

jblizzle said:
Personally I would stick with a single pump, then only run it in the day like you suggested for the secondary pump. But, whay happens if the clouds roll in or a storm? Not having it automated can cause you to lose a lot of heat if running solar when there is no heat available. Keep that in mind.
Click to expand...
Yeah, i understand that on cloudy days.. i figured for initial testing (and with the panels just laying in the yard) I'd go without this expense. Now its a question of smartpool and fafco (i guess the same as mentioned) or Sunquest.. is it really not worth it to get one (with the eventual goal) of putting on the roof, the roof kit or any kit they come with? Ill probably head to lowes though, to get pvc to interconnect these from what i've been reading.. any thoughts on that.. Also.. for these domes i was testing, this is the diverter kit i've been using.. is this at all useful with these solar panels.. i have 1.5" pvc going to the diverter kit.. or am i better off with something different.

Also debating to go for the full 160sq feet at first, or start with 80 then addon the other.. if its in the grass as a test, i'm guessing it wont be that hard to add a second set in a week or two after testing?

- - - Updated - - -

ashtonfitzgerald said:
Last year threw together a DIY panel as a test using poly irrigation tubing for our small AGP (~1700gal). End result: $100 total invested and it made hot water.

In terms of efficiency for the space, flow and area it took up--I have no comparison to a commercial system. I don't think it's been mentioned but solar is only practical if you have a way of keeping the heat in the pool. I ended up using our solar cover combined with foam pads floating on top to insulate at night and minimize evaporation. During the cool nights of September the pool would only drop to 70ish degrees. Without the covers it was chilly in the AM!

The setup involved a diverter setup sending water from the pool inlet to the solar array which consisted of two 100' coils of 1/2" poly pipe in parallel. This was very small diameter which reduced the flow a lot and the diverter was set to near full solar flow. If I opt to do this again, there will be at least another two coils to increase the flow through the system. On the hot return to the pool we would see anywhere from a 2-6 degree gain. I measured the flow through the panels and the best I could get at the time was about 2.2gpm (132gph). I worked out the math and this was an average of 2200BTU output on a sunny day from the 4'x8' footprint.

The end result was our small "junior" pool was swimmable until early October (unheard of for Canada!!). My last dip was at 72 degrees on the Thanksgiving weekend which is the second weekend of October up here.

What I would change:

Pool location. Last year we had the little intex setup in a convenient spot for power access, but that meant shade through the hottest part of the day. We effectively lost passive solar gain because of that. We are moving the tub to better location this spring.

Increase flow through the system. Increasing the diameter of the solar coils or possibly adding more of them.

Possibly adding in a secondary pump just for the solar system and losing the diverter setup.

Lessons learned: Keep the heat in! Before I was using the cover on the pool, we'd often lose the entire solar gain from the previous day. Especially as the nights got cooler.

If this was intended to be a permanent setup for a larger pool, I'd have to look at the cost investment/BTU of a commercial system. Bottom line is if max efficiency is required, there are better systems out there. For just making warm water, it can be done inexpensively.

-Ashton


Sent from my iPad using Tapatalk
Click to expand...
It sounds as if you did well given the size of your setup. It also sounds like the 2-6 degree gain follows the mentality of heat alot of water a little better than heat it a lot anyway i guess. I've noticed without the solar cover at night losing 2-4 degrees in april in the NE.. however.. leaving the "blue" cover on in the day hasnt gained anything.. on a 70F day the pool gains about 4F on its own with no help.. i guess i'd need to remove the cover during the daylight hours (or get a $75 12mil clear one and leave it on).. and only put it on at night.. over the last 3 days the AM averaged 57, while by night it was 61, i guess had i covered it only at night with no assistance from domes, etc, i may be at 65 or better now at least, just a guess.
 
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