Solar heating panel

[wayneb]

Hi guys,

I was initially considering building a DIY solar panel out of hose, but due to the cost I'm considering buying a ready made panel off of ebay.

I've got all the necessary tools to do the job, and have done plenty of DIY projects in the past so pretty handy there, but the cost is what got me. The hose alone was going to cost about $25 per 15 meters (50 ft)!!!

I'm looking at something like http://www.ebay.com/itm/190872051143?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

Has anyone used these before and can offer an opinion? I don't want to spend too much as I only have a 10' Bestway AG pool, and don't really want to spend more than the pool is worth.

 

[Isaac-1]

These kit style kits tend to cut a lot of corners in the name of keeping the instructions simple, in my opinion they cut too many corners, but you have to remember the more idiot proof they make them the fewer returns / complaints they get. The trade off is often getting less than optimal installations, shorter service life, etc., this is not to say anything at all about the quality of the panels, however there do tend to be tradeoffs there too as these kits tend to be made from thinner/more flexible materials than some of the better commercial panels in the name of easier / lower cost shipping.

Now for a few bullet points on solar panels, sizing, etc.

Any solar panels beat no solar panels when it comes to heating a pool, however to get a noticeable extension to your swim season you generally need solar heater panels with an effective size between 50 -100% of the surface area of your pool depending on your climate and desired amount of heat.

You are at about 41 degrees south, so for U.S. solar sizing references I would suggest using the ones for Chicago which is at about 41 degrees north

Your pool is about 110 sq ft in size these panels appear to have about 40 sq ft per panel (assuming the 28 inch width includes the gap in the middle), so to get an effective amount of heat you will need at least 2 panels for 80 sq ft of area. Although given your relatively high latitude you might even want to go with 3 panels for 100%+ coverage depending on how well they are placed.

Optimal tilt for your area will be around 45 degrees facing south if you go with 2 or 3 panels as you likely will want optimal angle for spring / fall, not optimal year round / summer angle which will be shallower. This is because you likely want maximum heat output in the spring / fall months and don't likely care about maximum heat in the middle of summer.

As to hose pipe, etc. most fixed residential solar heaters use common PVC pipe, it does not have to be anything special if you do use PVC paint it to avoid UV breakdown. Here in the U.S. 1.5 inch PVC cost about $5 per 10 ft section and couplers run less than $1 each depending on type.

Ike

p.s. this page has lots of good information on mounting etc of similar style panels

http://www.h2otsun.com/rackground/index.html

 

[wayneb]

Thanks for that Ike. My main motivation for getting something like this isn't to extend the swimming season; it's to get my wife in the pool during the summer.

During the summer months, our pool gets up to around 25C (77f) degrees, which in my opinion is a lovely temperature for me and the kids. My wife thinks that is cold and refuses to get in. All I really want is to get an extra few degrees to entice her to take a dip, so not asking the solar panel to do too much. I have a south facing roof at about 45 degrees and this gets almost all day sun in the summer, so that is not a problem. The pool also gets all day sun.


We have a local indoor pool with slides and a wave pool that the kids like to go to during the winter, so our little AG pool is really just to splash about in during the summer.

 

[Isaac-1]

In that case you may get enough heat out of a single panel in the prime summer months, but I would still strongly suggest getting 2, the plumbing cost and installation effort will be about the same.

Ike

p.s. one down side to these longer flexible horizontal panels is they can trap water which will expand and crack if it freezes, so if you if you choose to install them roof top, allow for some extra fittings / valves so you can blow them out with air (shop vac, or leaf blower) and isolate them during cold weather.

 

[wayneb]

I'm actually starting to think it might be a better idea to mount on ply wood as a more temporary set up, and put away when not in use. That way if we ever get a bigger more permanent pool, I can get some "proper" solar panels put on the roof without the hassle of pulling these ones down...

Wow, shipping to NZ on ebay is REALLY expensive!!! Another more local option is something like this - http://www.trademe.co.nz/building-renov ... 921992.htm

Would that be a better option? I little more expensive, but looks really simple and more robust...from the pictures at least anyway.

 

[Isaac-1]

I can't comment much on those style panels, as far as I know these waffle style panels are not sold in the U.S., but I have seen them mentioned by members in AU and maybe NZ before.

Ike
p.s. you might check out prices from Amazon Global

 

[skeeter_ca]

Not to say there is anything wrong with manufactured panels, they are a good choice nowadays but have you seen this site on DIY stuff. If it's just a small pool it might be more economical than the manufactured panels. Especially with your shipping cost. Just remember the same area rules apply to DIY panels.

http://www.builditsolar.com/Projects/Po ... eating.htm

skeeter

 

[Isaac-1]

I have seen that page before, be ware of some of the information presented in the links, there are some very flawed conclusions based on "common sense" not engineering, when it comes to things like flow dynamics and thermodynamics there are a lot of common sense things that are simply wrong.

Ike

 

[wayneb]

The DIY option isn't really an option. The cost of the materials here is crazy and will cost almost as much, if not more, than a relatively cheap manufactured panel. That waffle style in my link is available locally and looks like it wont take up too much room, and could be easily moved during the day to get the best out of the sun. Also, at the end of the summer I can pack it away in the garage along with the pool.

I've got a year to make up my mind.