Cheap solar heater technology recommendations?

**russ** · 08-11-2014, 09:47 AM

Hi and welcome to Solar Panel Talk!

Flat plate collectors can achieve 60° C - they are less expensive and less troublesome.

What are you heating water for?

Russ

**J.P.M.** · 08-11-2014, 10:02 AM

Originally posted by samsagaz

Hi guys, here in argentina Vacuum tubes (heat pipe) are very very expensive, want to know if someone know other good eficiency technology to use as solar heater.

I read some good reviews abt use plastic bottles and glass bottles but nothing that compare it with commercial technologies. Mainly i want 60C in my watter.

Sorry for my english!

Regards

Your English is a lot better than my Spanish.

Depending on your coldest weather and with it the possibility of damage by freezing, something called batch heaters can be effective. check out a website called builditsolar.com. there's lots of stuff/ideas there.

Vacuum tube collectors as water heaters are overkill, technically and financially.

**samsagaz** · 08-11-2014, 10:51 AM

Thanks guys, well, mainly will be used for my Home baths and if is possible want to use it in conjunction with my boiler to heat the radiant floor instalation.

winter
máxima 33.4º C
mínima -8.1º C

summer
max 41C
min 5C

spring
Max 39.5C
Min 6.3C

fall
máxima 37C
mínima -5.6C

Both can be made by myself!

I can weld cooper !

Using Flat plate collectors will get more temperatura than using batch heaters right?

**J.P.M.** · 08-11-2014, 11:41 AM

Originally posted by samsagaz

Thanks guys, well, mainly will be used for my Home baths and if is possible want to use it in conjunction with my boiler to heat the radiant floor instalation.

winter
máxima 33.4º C
mínima -8.1º C

summer
max 41C
min 5C

spring
Max 39.5C
Min 6.3C

fall
máxima 37C
mínima -5.6C

Both can be made by myself!

I can weld cooper !

Using Flat plate collectors will get more temperatura than using batch heaters right?

Flat plate will probably be a more efficient choice for what you describe. Remember, you are after quantity of heat (BTU's, Joules, etc.), not necessarily quality (temperature).

Good thermal designs provide temperatures high enough to do the job, but no higher than necessary plus maybe a BIT higher for some flexibility.

**samsagaz** · 08-11-2014, 11:49 AM

Originally posted by J.P.M.

Flat plate will probably be a more efficient choice for what you describe. Remember, you are after quantity of heat (BTU's, Joules, etc.), not necessarily quality (temperature).

Good thermal designs provide temperatures high enough to do the job, but no higher than necessary plus maybe a BIT higher for some flexibility.

So i can make an bigger plate instead purchase vacuum heat pipe, right?

Is possible to calculate how will be the highest temperature that can collect ¿ and how calculate the size of the flat panel?

I was thinking abt make one using copper tubes, like i see in some videos, but cant figure how transfer taht temperature to the radian floor system. Floor sytem use Pex tubing, if mix with copper, i get into troubles i think, Pex tubing dont have anti oxygen barrier :/

**russ** · 08-11-2014, 11:54 AM

Look at http://www.builditsolar.com/ many designs for DIY

Keep coming here and the guys will help you - some good assistance available from several.

Flat plate is what you want - look at the drain back type.

**samsagaz** · 08-11-2014, 11:56 AM

Originally posted by russ

Look at http://www.builditsolar.com/ many designs for DIY

Keep coming here and the guys will help you - some good assistance available from several.

Flat plate is what you want - look at the drain back type.

Thanks!

**LucMan** · 08-11-2014, 07:16 PM

Originally posted by samsagaz

So i can make an bigger plate instead purchase vacuum heat pipe, right?

Is possible to calculate how will be the highest temperature that can collect ¿ and how calculate the size of the flat panel?

I was thinking abt make one using copper tubes, like i see in some videos, but cant figure how transfer taht temperature to the radian floor system. Floor sytem use Pex tubing, if mix with copper, i get into troubles i think, Pex tubing dont have anti oxygen barrier :/

You can use a heat exchanger to transfer the solar heat to the floor radiant. A pipe in a pipe heat exchanger is easy to make yourself with 2-6 foot pieces of pipe.
Google home made heat exchanger.

**J.P.M.** · 08-11-2014, 07:39 PM

Originally posted by samsagaz

So i can make an bigger plate instead purchase vacuum heat pipe, right?

Is possible to calculate how will be the highest temperature that can collect ¿ and how calculate the size of the flat panel?

I was thinking abt make one using copper tubes, like i see in some videos, but cant figure how transfer taht temperature to the radian floor system. Floor sytem use Pex tubing, if mix with copper, i get into troubles i think, Pex tubing dont have anti oxygen barrier :/

Answers to your questions are yes and yes, and are some of the heart and soul of solar thermal design. Finding the numbers and the best design involve more space than a forum such as this allows to answer properly. I'd suggest start with small DIY projects while reading a solar textbook. You will eventually be able to answer those questions and many more on your own, with some guidance from places like this as you generate more questions.

**samsagaz** · 08-12-2014, 05:36 PM

Originally posted by LucMan

You can use a heat exchanger to transfer the solar heat to the floor radiant. A pipe in a pipe heat exchanger is easy to make yourself with 2-6 foot pieces of pipe.
Google home made heat exchanger.

After read looot of posts and websites, looks like the main problem is to mix copper with pex, will get problems in my floor system if mix that. And using an pex coil tubing inside the heat exchanger are not so efficient as copper, right? :/

**J.P.M.** · 08-12-2014, 07:08 PM

Originally posted by samsagaz

After read looot of posts and websites, looks like the main problem is to mix copper with pex, will get problems in my floor system if mix that. And using an pex coil tubing inside the heat exchanger are not so efficient as copper, right? :/

I'm not a big fan of PEX, and even if I was, I'd not use it as a heat exchanger component.

**samsagaz** · 08-12-2014, 07:32 PM

Originally posted by J.P.M.

I'm not a big fan of PEX, and even if I was, I'd not use it as a heat exchanger component.

Ok, then will purchase 15mts of copper and will make the exchanger coil with that! but in all the other parts will use pex.

3/4 Pex in argentina cost like 1USD/mt and copper like 9USD/mt

Amazing right?

**J.P.M.** · 08-12-2014, 08:02 PM

Originally posted by samsagaz

Ok, then will purchase 15mts of copper and will make the exchanger coil with that! but in all the other parts will use pex.

3/4 Pex in argentina cost like 1USD/mt and copper like 9USD/mt

Amazing right?

I'd also consider what it costs to get at, service and replace if/when it fails in any application.l

**russ** · 08-13-2014, 01:33 AM

PEX can not be exposed to sun light

PEX has temperature restrictions - look them up.

Cheap solar heater technology recommendations?

Cheap solar heater technology recommendations?

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