Solar Water Heaters

[Morakot]

Mr Bluesofa's recent topic showed that there is a genuine interest in solar water heaters.

 

We should have a dictated to thread on this topic. Anything from various DIY designs to the use of off-the-shelve components, costs, practicality. There is also an archived thread on solar heaters in the electric form, you might like to check out.

 

Please share your photos, drawings, and experiences! Discus your plans and ideas.

 

So far we heard about coil designs, required titling angles, usable water temperatures, and what not..

 

 

 

 

 

[Morakot]

4 hours ago, bluesofa said:

 

The water quantity on the roof is not the end of the story – for myself.

As I said, I’m using the pipe initially to do some testing on how well the sun heats up the water in it.

If everything works out, eventually I plan to connect it to a 200L water tank to heat that amount of water for domestic use.

However, if 80L is enough for you, then buy 100m coil of 32mm diameter LDPE pipe for 1,000 Baht and try it for yourself. That coil will hold about 80L of water.

 

(edit) BTW, wrapping that size pipe into a single row flat coil will give you an outside diameter of 2m. This is as far as I've got, see the attached:

 

 

[Morakot]

 @bluesofa, are you placing the coil in a box?

[eyecatcher]

The first time I saw this idea...(and theres loads of you tube videos showing how to make it) I thought it was so brilliantly obvious I wondered why Ii hadnt thought of it myself!

 

Actually I thought this is going to impress the inlaws out in Isaan in the middle of no where with no hot shower.

 

Then I saw so much negativity about it, it wont work, you need to spend on a boatload of electrical gubbins to save it, you need to keep moving it every day with the sun, change the angle, you have to paint the tube, you have to use clear on and on.

 

For an out in the sticks makeshift hot water water system on the cheap I thinks its viable but then again anyone can just go and buy a shower heater for 2k and its done.

 

 

 

 

 

[Morakot]

Cheers Eye. Yes cost is an important factor and it possibly only makes sense in the longer run. But most people in this country don't think like this and are happy to put a single 2k THB unit on to the wall. Others however spend about 8K THB on a powerful under-the-sink unit that supplies water to three points in a bathroom. 

 

A multipoint system, especially if it has a dishwasher or washing machines connected, should also have a tempering valve. This would mix cold and hot water of a simple passive system that does not require tanks. It not only keeps the temperature from spiking up, but also increases how much "hot" water you can use.

 

Starting point is about 35 GBP/EUR for a decent model that you can set between 45 - 65 degrees C.  Whether these are available here I have no idea.

 

 

 

 

PS: Check out this vdo. A much smaller setup than Bluesofa's that is supposed to deliver between 55 - 65 C throughout the day. Heating up times when completely used up is between 30-60 mins.

 

 

[Morakot]

22 hours ago, BEVUP said:

Not a problem

Heating times 9 am - 3 pm is the best depending on conditions

Without getting into the technical side of things I put 500 mtrs of 16 mm tubing on the same type of roof

First i put down 4 X 6 mm Hardi plank sheets ( just screwed them into every 2 nd roof sheeting spot where they skipped for the roof sheet fixing )

Then I ( well started , the Cambodians finished ) , laid the coil in an oval shape covering a 4.8 m X 2.4 mt area

I use it for my wading pool & divert some of the water from the outlets to a secondary small pump ( pond pump with 5 mtr head ) - this seemed to work best ( maybe friction as even the pool pump alone only to coil wasn't that good )

It gets hot

 

@BEVUP Great! Would you mind posting some pictures of this oval shaped coil? Cheers!

[BEVUP]

6 minutes ago, Morakot said:

 

@BEVUP Great! Would you mind posting some pictures of this oval shaped coil? Cheers!

Will try as I'm sure I wasn't able to last time i tried , so might take a bit

[BEVUP]

[BEVUP]

4 minutes ago, BEVUP said:

As mentioned finished by the Cambodians so got a little messy but still ok

You may notice some little blue caps - thats because the hardware didn't have any straight 16 mm joiners (not out of stock ) just no have - UNBELIEVABLE 

The plastic strap holding it down is step edging - should be uv rated

[Morakot]

On 10/2/2017 at 5:48 PM, sometimewoodworker said:

That is a system designed for temperate zone areas in much higher latitudes than the tropical zone we are in. It is significantly over engineered (so ridiculously expensive) for Thailand, it may well be capable of producing water at over 90 degrees centigrade.

 

 

 

 

 

 

 

 

[Morakot]

On 9/18/2017 at 1:54 PM, BEVUP said:

 

 

Very nice set up  @BEVUP! What kind of temperatures you're getting with it?

[BEVUP]

1 hour ago, Morakot said:

 

Very nice set up  @BEVUP! What kind of temperatures you're getting with it?

 

Well as you know it depends on the skies

I think 30 sec would give me 2 liters, & all I can say that at the best of times you cant leave your hand under it & the Temp joiner I put in near the outlet 16 mm push on PVC (cant recall grade ) was gradually bending with the lay of the black poly 

Really cant find a decent Thremometer