best type of water system flat, tube, tank in or outside?

[rainworm]

I keep getting distracted by the sales pitches lol. What is better?
Heatloss for tank mounted on system vs tank in house and system on roof.
I intend to fill tank up with antifreeze.

tube system roof.jpgground water system.jpg

Tubes system vs flat panel system.

[LucMan]

I keep getting distracted by the sales pitches lol. What is better?
Heatloss for tank mounted on system vs tank in house and system on roof.
I intend to fill tank up with antifreeze.

[ATTACH=CONFIG]2596[/ATTACH][ATTACH=CONFIG]2597[/ATTACH]

Tubes system vs flat panel system.

Flat plates are my choice.
I don't think that you want to use anti freeze for bathing, laundry etc. The tank never uses antifreeze, the connecting piping between the heat exchanger and the collectors may.
Depends on what type of climate you live in.
Warm where it never freezes tank out side is ok.
If freezing temps are anticipated tank inside only.

[peakbagger]

Depends what you are using it for. Flat plates are the most efficient at collecting heat, the down side is that at best they add 80 degrees to the outside temperature. If you are in a cold climate and its 20 degrees outside, the flat plates will only get the water up to 100 deg which is below what most folks want to take a shower. Tubes have lower efficiency but they put out higher temperatures, on the same 20 degree day you can get to 140 degrees. The trade off is you need more tubes at a higher price to collect the same amount of heat.

There is not much that can go wrong with a flat plate collector unless you let the antifreeze get acidic due to overheating. Overheating flat plates rarely happen but tubes style collectors need to be designed with a way to get rid of heat in the summer that is foolproof as they will boil and that can ruin the anitfreeze. Some people put in heat dump exchangers and other just cover the tubes in the summer.

Tube type collectors dont work well in snowy conditions, they dont melt off as quickly after a snowstorm as flat plate.

[rainworm]

degrees

Well the tank is heated now with the grid electricity. The tank boils during the night and at 6 the power is shut off. It stays in the well isolated and in the afternoon it would be around 60 degrees. when it gets to the shower cubicle it is barely warm enough to shower. Insulating it better is not a option. So 60 degrees celcius is definitly not enough. 70 degrees would be. 120 would turn it in to a sauna so I take it you are talking fahrenheit instead of celcius.
60 C is 140 fahrenheit.70 C is 158 Fahrenheit.

[russ]

warm climate = flat plate

cold climate = vacuum tube

[rainworm]

pipes

The pipes seem to break a lot under heat, is 30 degrees celcius in summer too hot? Can this system not be filled up with frying oil instead of antifreeze?

[russ]

My tank temp, in the summer, runs above 90°C

[rainworm]

pipes

The pipes seem to break a lot under heat, is 30 degrees celcius or 86 fahrenheit in summer too hot? Can this system not be filled up with frying oil instead of antifreeze?

I was thinking of the following since we have high volume of wind here. Tubes on roof, (better for wind right???) Or should it be plates for more heat in windy conditions? What are plates made of, copper pipes in a glass housing? unpressurised all glass solar vaccuum tube.JPGtank inside, low pressure system (otherwise with breaking pipes in watertank the antifreeze escapes), water in tank, antifreeze or oil in tubes, expansion tank in attic above the rooftubes, pump on solar. Or am I getting the wrong idea of this solar? The things I read are chinese english so not much explenation of what a system really is.
There is copper pipe in tubes and vaccuum tubes. There seem to be more types of tubes. solar vaccuum tube, three target vacuum tube.JPGsingle target tube.JPGsolar vaccuum tube.JPGsingle target tube, three element tube. three target vacuum pipe with temperatures up to 400 degrees celcius does not break due to heat. and solar evacuated tubes. Pipes seem to break a lot. What is that three target vacuum pipe I cant find it elsewhere and the supplier is gone on holidays. p.s. sometimes it freezes slightly here. but only minor bit, no snow.

[cssolar]

compact vacuum tube solar water heaters

The pipes seem to break a lot under heat, is 30 degrees celcius or 86 fahrenheit in summer too hot? Can this system not be filled up with frying oil instead of antifreeze?

I was thinking of the following since we have high volume of wind here. Tubes on roof, (better for wind right???) Or should it be plates for more heat in windy conditions? What are plates made of, copper pipes in a glass housing? [ATTACH=CONFIG]2600[/ATTACH]tank inside, low pressure system (otherwise with breaking pipes in watertank the antifreeze escapes), water in tank, antifreeze or oil in tubes, expansion tank in attic above the rooftubes, pump on solar. Or am I getting the wrong idea of this solar? The things I read are chinese english so not much explenation of what a system really is.
There is copper pipe in tubes and vaccuum tubes. There seem to be more types of tubes. solar vaccuum tube, [ATTACH=CONFIG]2601[/ATTACH][ATTACH=CONFIG]2602[/ATTACH][ATTACH=CONFIG]2603[/ATTACH]single target tube, three element tube. three target vacuum pipe with temperatures up to 400 degrees celcius does not break due to heat. and solar evacuated tubes. Pipes seem to break a lot. What is that three target vacuum pipe I cant find it elsewhere and the supplier is gone on holidays. p.s. sometimes it freezes slightly here. but only minor bit, no snow.

There are 3 main types of compact vacuum tube swhs ( stand alone plug and play systems ),

TYPE 1 - direct non pressure unit, the vacuum tubes have water in and plug into the main tank which is not a pressure vessel ( gravity feed to house )

TYPE 2 - indirect pre heat unit, the vacuum tubes and tank are same as the non pressure unit but inside the tank is a copper coil heat exchanger for passing water at mains pressure to be heated indirectly ( this unit is not gravity feed and can be mounted lower than the point of use )

TYPE 3 - direct high pressure unit, heat pipes in dry vacuum tubes that heat water in a pressurised water tank ( this unit is not gravity feed and can also be used lower than the point of used.

I choose to sell the 2nd pre heat type as the water quality is poor here and I have seen problems with calcium build up and failure of pressure relief valves on high pressure units, where as the pre heat type has a vented main tank so no pressure build up is possible.

I cant comment much on flat plate units as I don't have too much to do with them, but I get the feeling generally people trust them more as they have been about for a long time and are well proven.

I run vacuum tubes on my own house and have so since 2008 and am pleased with the performance
today has been sunny but with a very cold wind my swh got up to 55 degrees centigrade and 4 of us all had a hot shower !

Generally I have found that if the temp is 48 or over it is ok for a shower.

Any way I think all use of solar is good and hope you find a suitable swh for your location and needs

ps tripple target tubes are higher performance, use water not oil !!!
Tony

[rainworm]

solar

yes solar use is good! I solarbathe and brown in summer.
We have lots of calcium in the area in the water and need to clean the coffee machine every week.
So 3 systems, is the middle system called split pressure non pressure system? I came accross that.
Chinese example of what tube they use:

Split Pressure Solar Water Heating system,

Features :

1,Heat Pipe:faster speed for heat transfer,more than copper 1000 times.

2,Freeze Protection: Because the heat pipe is located within the evacuated glass tube, brief working temperatures as low as -20oC (14oF)

3,Working pressure:6.0 bar for working,9.0 bar for testing,suited for existing government cold water supplier

4,Safety:no water in tube,if tube broken,no water lose.

5,High efficiency and temperature:highest temperature arrive 350 degree.

Still no idea of what tube this is, 3 element tube or single element tube or tube with a bulb on top or one that lets water in and out through a pipe...
you get the general idea. reading this chinese supplier you knnow less instead of more.

So you think I should go for non pressurised tube that feeds a pressurised spiral in a tank? what is the tank filled with? antifreeze? the spiral then goes to the watertank in the house, is it not pumped back if the water in the main tank in the house is colder than the water in the solar heater?
Sorry for asking all these questions.

[cssolar]

pre heat swh

Hi the pre heat type is a compact unit not a split system

COMPACT means all in one unit collector and tank joined ( thermo siphon circulation )

SPLIT SYSTEM means collector and tank separate ( forced circulation with a pump ), vacuum tube split systems generally use heat pipe high pressure collectors

If your water quality is poor and you want a low cost system Chinese units work well ( insist on good quality ask for references ) there are over 4000 factory's producing swhs in China alone so choose wisely .

If you want high pressure but have low water quality, I recommend either a non pressure swh with an auto boost pump or a pre heat unit with a copper coil heat exchanger

Personally I like the pre heat unit because

1 low cost

2 easy to install

3 non pressure tank ( so in the event of over heating water and steam can boil out )

4 indirect ( so you can add anti freeze to the tank water ) but To be honest here in Spain its not usually required unless at high altitude

5 water in tubes gives extra water storage ( and as hot water is used cold water will go to the bottom of the tubes forcing hot water up into the tank )

6 vacuum tubes are easy and quite cheap to replace ( although I have found them very reliable and only seem to get damaged with poor handling or filling hot tube with cold water ( poor installation )

On the down side

A thermo siphon system has no control on the max temp, as the water naturally circulates it gets hotter and hotter

so for safe operation in the summer it is advisable to limit the max temp out with a thermostatic mixer

Also if the unit is not in use in the Summer ( for example the owners go on a long holiday ) it is important to cover the collector ( in affect turning the power off ! )

If you feed your existing electrical cylinder ( if it has a thermostat ) you can leave it plunged in and will just top up the heat when required, but it is good to fit a by pass so you can also use the solar heated water direct

Cheers Tony20091812398564.jpg

[rainworm]

Thank you for the explenation. This helped a lot.
I will go talk to the company now.

[rainworm]

builing a system

So I now have glass tubes only. There are some internet instruction videos on how to build a system from that on youtube but it looks like they do not want to connect them to their water system in the house.
How can I build a reliable system that connects with my high pressure tank?
Also some questions. Why do you put the copper rods in the tubes, is it not also possible to put the water directly in the tubes? Or is the pressure too high?
Why use the rods and not copper pipes with water flowing in them? I think of small copper pipe going straight down then spiralling up. http://www.weddingforyou.co.nz/shop/...rty-straws.jpg like this but going down straight in the middle.
What is needed to make the system withstand the high water pressure of a home system?

[inetdog]

So I now have glass tubes only. There are some internet instruction videos on how to build a system from that on youtube but it looks like they do not want to connect them to their water system in the house.
How can I build a reliable system that connects with my high pressure tank?
Also some questions. Why do you put the copper rods in the tubes, is it not also possible to put the water directly in the tubes? Or is the pressure too high?
Why use the rods and not copper pipes with water flowing in them? I think of small copper pipe going straight down then spiralling up. http://www.weddingforyou.co.nz/shop/...rty-straws.jpg like this but going down straight in the middle.
What is needed to make the system withstand the high water pressure of a home system?

Evacuated glass tube systems do not want to run the water tubes down the inside since it creates too much chance of leakage as well as for other reasons. The "copper rod" in a commercial evacuated glass tube is not a solid copper rod, but a heat pipe which very efficiently transfers heat from one part of tube (the solar heated part) to another (the manifold where it gives up heat to the pumped water.)
This allows you to attach and detach tubes without and need to shut down or drain the system and keeps the sometimes pressurized part of the system easier to maintain.

And finally, if you are using this to directly heat domestic hot water, it allows you to keep all of the plumbing which carries the water free of contamination.

[rainworm]

seal

But then how does the seal work in the tank where the copper rods fit into? Is that a special seal?