Solar Syphon

zoom_cool

Has anyone use the Willis Solar Syphon any info would be great as I am thinking of installing one.

purebokety

I have also been looking at this,it it says on the website that you should be able to pre heat your hot water faster(earlier shower).It also has the advantage of cost (retrofit) as there is no need to replace your boiler with a dual coil .Also if you look on the companies website there is a report done on how the system performs .I Wish i could give you some more info here, only discovered the Solasyphon recently too.Anyone out there have one installed and how has it run so far?

quentingargan

I don't personally have one, but looking at the method by which it works, I reckon it would perform bettter with tubes than with flatplates. It has the advantage that it heats water at the top of the cylinder first, so if you get an hour or two of sunshine, you might get 50L of nice hot water rather than 200L of luke-warm.

The panel runs hotter with this system, which is why evacuated tubes, because of their better insulation, would be a better match.IMHO

ccsolar

We have only ever fitted 2 of them and they work fine, we also came across 1 fitted in a house when we were doing a repair on a flat panel system
They seem to work fine , if fitted correctly.
I think Copper Industries in Antrim actually make them for that company, way better than the solar plug option in my opinion..
Should cost under the €200 mark from what I can remember..
Cc

zoom_cool

Thanks guys for responding back I was going to use it with Flat Panels dont have them yet why are the tubes better is it because they heat up to a higher temp? My cyclindar size is 120 litre it should be ok with 2 flat panels they are quiet expensive around €250

purebokety

Flat panels have a longer shelf life according to what ive been told ,they are a lot heavier than tubes which makes getting them onto the roof more difficult,some people prefer their aesthetics.
Tubes and manifold can be assembled on roof piece by piece and are easier to install for this reason,you also need a pump station, control panel ,expansion vessel and fittings piping to complete your system which can add a lot of euros.Solar panels for domestic hot water are a good idea though
Search boards.ie a bit more i am sure there is a lot more detailed info here on your question, heres a link to more info http://www.boards.ie/vbulletin/showthread.php?p=59524548 ,all the best with your install.

quentingargan

zoom_cool wrote: »

Thanks guys for responding back I was going to use it with Flat Panels dont have them yet why are the tubes better is it because they heat up to a higher temp? My cyclindar size is 120 litre it should be ok with 2 flat panels they are quiet expensive around €250

Flatplates are less efficient at high temperatures than tubes because of increasing temperature difference and heat loss across the glass. In a conventional solar cylinder, the panel is heating cold water at the bottom of the cylinder initially, slowly rising to a higher temperature as the day goes on. So your panel spends the first half of the day at 30 to 40 degrees. Much better for flatplates, only spending the end of the day at 70 degrees plus.

The solar syphon starts moving water once the water in the syphon is hotter than water at the top of the cylinder. For that reason your panel will be running at a higher temperature. I expect this would make very little difference with tubes, but more of a difference with flatplates. But as I said initially, this is just a theory - I don't have practical experience of using the device to back that up, so if csolar has seen this working well, I then the theory might not be borne out in practice.

zoom_cool

Thanks guys for all the useful information I am hoping to get the 2 panels and pump station and controller and PT1000 probes for €500 and pay extra for SolarSyphon I will let you know how I get on.

John T Carroll

zoom_cool wrote: »

Thanks guys for all the useful information I am hoping to get the 2 panels and pump station and controller and PT1000 probes for €500 and pay extra for SolarSyphon I will let you know how I get on.

Willis Solasyphon in N.Ireland manufactures one of these devices. One concern would be how this would interact with auxiliary heating, ie boiler coil and/or Electric Immersion due to destratification if both the solar syphon and the auxy heating are both on. Tests were done by some university in the UK on the Willis Solasyphon (should be readily available online) but this was purely to evaluate its performance and obviously did not include any form of auxiliary heating. I have read a few reports over the last few years and it would seem to be vital that these (solar syphon units) are installed correctly. If you have a top immersion facility on the existing cylinder you could fit an immersion type coil which has an electric immersion element included in it, I think the coil area is about 0.65? M2 which should be ok for a max of 2 Flat plates or, at a push, 30 E.Tubes. JTC

Henry Ford III

Is anyone actually running a solar syphon and solar panel with an open vented sytem? How does it work in terms of volume and temperature of the water?

What's the total costs? Are grants available? Is the install as easy as described?

I'm a bit green on all this.

Henry Ford III

Anyone?

John T Carroll

Henry Ford III wrote: »

Is anyone actually running a solar syphon and solar panel with an open vented sytem? How does it work in terms of volume and temperature of the water?

What's the total costs? Are grants available? Is the install as easy as described?

I'm a bit green on all this.

This is a bit of a roundabout answer: I would only consider a solar syphon system in conjunction with E.Tubes as the primary flow temperature has to be as high as possible to promote secondary circulation, flat plates are fine at lower temperatures but once the collector temperature goes above 60C then their performance falls off except on the rare occasions of very high solar radiation. I would consider them to be next to useless with a solar syphon system.
I am presently helping a friend who has a E.Tube array fitted and is just using a 150 litre indirect copper (vented) cylinder and he has fitted a very low head secondary circulating pump and external heat exchanger to circulate the water around the cylinder, early results are reasonably promising but wont be in a position to give (you) final settings/results for a few weeks as adjustments and orifice plate fitting is still ongoing. The power consumption of the secondary pump should only be around 10/15 watts.
Neither of these systems, in my opinion, will be as good as a dedicated solar coil in the cylinder. Do you wish to use an existing vented cylinder?.
No, I don't see any reason why a solar syphon cant be fitted to an open vented system. The Willis SolaSyphon system with an electric immersion has been used for years with open vented systems especially in the UK.

Henry Ford III

Yes JTC I have an existing vented cylinder with a dual immersion. My roof has a southerly aspect which is good news presumably?

I think I'll give Willis a call and see what they have to say.

John T Carroll

Henry Ford III wrote: »

Yes JTC I have an existing vented cylinder with a dual immersion. My roof has a southerly aspect which is good news presumably?

I think I'll give Willis a call and see what they have to say.

Southerly orientation is perfect. Also 2 F.Plates for a 120 Litre cylinder is a very good fit, I have 2 F.Plates + a 150 Litre twin coil vented copper cylinder, the cylinder cost me €457 in August 2011. If I were to go the solasyphon route I would install a 30 Tube system in preference to the 2 X F.Plate. For example, the energy required to heat say 50 Litres of water from 20C to 50C is 1.75 Kwh, the E.tubes will achieve this in two hours of sunshine with a solar intensity of 475 watts/M2 (assuming 70C collector temp & 15C ambient), the F.Plate(s) will require 610 watts/M2 under the same conditions. Now the one thing that we have no control over is obviously the solar radiation intensity so the E.Tube, (again in my opinion) is a better fit if one wants small quantities of higher temperature water more quickly.

Danpat

I'm just in the process of fittin one.made the siphon myself with 2" copper and an 8mm copper coil.ive got 16 tubes.better keep the siphon below the cylinder to stop reverse circulation when the siphon goes cold.