Solartwin

danyosan

Anybody any experiences with them?

I am looking at solar heating systems at the moment and this is the best I've came across so far. There's no need for a buffer tank, the hot water is supped straight from the top of the heated water tank, thus saving a lot of space and cost and the water pump is photovoltaic. Seems the ideal system to me but there must be downsides.

Any help much appreciated and I welcome any alternative suggestions.

danyosan

Is the lack of replies to this topic due to people not having experience with this product or the fact that there's not really much known about the pros and cons of various suppliers by boards posters?

This was the best place I could come up with for a knowledge base on this topic so any help at all would be hugely appreciated.

Saw a demonstration unit in Birr a few weeks ago, it uses a high temperature rubber tubing as opposed to copper that most other panels use.

Rival manufacturers claim that the tubing will deteriorate and don't collect heat as well as other systems. I keep an open mind on that.

Not using a buffer tank is not a good idea as sometimes the output from the panel will be at a lower temperature than your tank, you'll end up cooling the water already in the tank.

The photo voltaic water pump is a good idea as it only runs when the sun shines, this reduces the amount of cold water pumped through the system.

I am looking at installing solar next year but I shall be going the DIY route.

saibhne

You will most likely only ever get heat from the panel when the sun is shining strongly, i.e. summer ( if you are lucky to get one that is) , and the PV panel will only operate effectively in direct sunlight, most other solar systems - particularly vacuum tubes, using mains pumps will operate to a greater or lesser extent all year round.

AFAIK The solar twin system also uses a direct input into cylinder as opposed to indirectly heating through a coil - this could cause calcification in your cylinder if you live in a hard water area, so you will need to take steps to ensure this won't be a problem.

Lastly the main reason they don't use copper I reckon is that the system will operate at lower temperatures than conventional solar systems meaning they can get away with using the rubber pipe. But you won't get the benefit of hotter water..

danyosan

Deleted User wrote: »

Not using a buffer tank is not a good idea as sometimes the output from the panel will be at a lower temperature than your tank, you'll end up cooling the water already in the tank.

.

My impression was that because of the PV pump this couldnt happen.

Am right in thinking that there is no real market leader in this sector at the moment. I havent heard of any clear advantages of any design out there.

saibhne

danyosan wrote: »

Am right in thinking that there is no real market leader in this sector at the moment. I havent heard of any clear advantages of any design out there.

There's no magic bullet when it comes to solar- each household has different needs and each system has it's pros and cons, Vaccuum tubes are the most efficient outside of Summer and are easier to install, Flat plates look good and if you get a good solid panel they'll last for 25 years.. the list goes on

Best thing to do is to assess your water heating requirement honestly and see which system suits you.. Five big questions:
What is your daily hot water requirement? Average calculation at 50L per person per day.
Do you have a South facing roof/site to install the panel?
What other means will you use to heat water in the colder months of the year? Oil/Gas/wood/electricity-coal?
Can you sacrifice aesthetics for efficiency?
What is your budget?

An average solar thermal system correctly designed can realistically give you about 50% of the energy required to heat your water per annum - if you want to increase this percentage you need to increase the size of the array you install.

danyosan

saibhne wrote: »

There's no magic bullet when it comes to solar- each household has different needs and each system has it's pros and cons, Vaccuum tubes are the most efficient outside of Summer and are easier to install, Flat plates look good and if you get a good solid panel they'll last for 25 years.. the list goes on

Best thing to do is to assess your water heating requirement honestly and see which system suits you.. Five big questions:
What is your daily hot water requirement? Average calculation at 50L per person per day.
Do you have a South facing roof/site to install the panel?
What other means will you use to heat water in the colder months of the year? Oil/Gas/wood/electricity-coal?
Can you sacrifice aesthetics for efficiency?
What is your budget?

An average solar thermal system correctly designed can realistically give you about 50% of the energy required to heat your water per annum - if you want to increase this percentage you need to increase the size of the array you install.

Thing is we dont know how many people it will be for. At the moment its only 2, but we will be planning a family so who knows how many it'll be in the future.
The roof will be south facing, additional heating will most likely be electric coil.

The house hasnt been built yet, only at planning permission stage, so we are very flexible with what we can consider at the moment.

rebelcork

Looked at solartwin system myself and got advice as regards the solar pump etc.As previous posts said you need very strong sunlight for to operate the pump.
I installed an Ulltech system, on my gable, in Feb.Had a few teething problems at the start but it works very well now.All my hot water needs since the middle of March were supplied by this system.Needed a new 200 litre tank installed in my hotpress and an expansion vessel in attic.It works using a closed system with an electric pump.The companies base is in Clonakilty so it was convienient to me in Skibbereen.If you want to pm me I can give you more details, By the way I am not a sales agent for the company !!

dhaslam

The Solartwin self install system has a UK price on their website of £2499 while a similar Navitron system is £799 or £1122 with a suitable cylinder. The evacuated tube sytem with a proper cylinder would give far better performance.
Also with a proper cylinder you have the use if the immersion which is important for dull days. Navitron have an extensive user website.

The pump only works when heat is circulated so electricity used is minimal. Directly linked solar pumps may have a limited life due to voltage fluctuation, a battery linked system operated by the controller would be better.

Barry Johnston

Hello, I'd like to state an interest as the supplier of Solartwin and to make a few comments, I hope not too provocative on the postings. Solartwin is a "transition technology" and is thus open to being genuinely misunderstood. It is a new concept in solar, being low flow, PV pumped and freeze tolerant and available as a direct retrofit most low pressure hot water cylinders. Solartwin's pipes are approved for hot and cold water use in UK. A water softener keeps it scale free in hard water areas. The silicone rubber pipes they contain are thermally conductive and extremely durable. The panel is available for SEI grants of 600 euro, if installed professionally. The pump can start at about 10-15% sunlight. Below this level the solar energy is so scant it is barely worth collecting. The pack is quite a complete one compared to most and it is inevitably not the cheapest - at first glance anyway. There are very few on-costs. The pack does include 30m of silicone pipe and a pump and a PV rather than a length of cable for you to hook up to a power station. Plus of course a 2.8 sqm panel and a load of fittings. If you want to drop us a line at hi@solartwin.com we can put you in touch with a user. Please just go solar with any technology. Most are great! Thanks for reading.

ullastumpf

my message is that we own a solartwin here in the North of ROI and not only does it produce plenty of hot water, but as our system is solid fuel central heating, it uses less heating material on sunny and sunnyish days, as the water in the cylinder is at least preheated and does not entirely be heated by our fuel. We are not facing south, but south-east, and still it is good value. ulla

saibhne wrote: »

You will most likely only ever get heat from the panel when the sun is shining strongly, i.e. summer ( if you are lucky to get one that is) , and the PV panel will only operate effectively in direct sunlight, most other solar systems - particularly vacuum tubes, using mains pumps will operate to a greater or lesser extent all year round.

AFAIK The solar twin system also uses a direct input into cylinder as opposed to indirectly heating through a coil - this could cause calcification in your cylinder if you live in a hard water area, so you will need to take steps to ensure this won't be a problem.

Lastly the main reason they don't use copper I reckon is that the system will operate at lower temperatures than conventional solar systems meaning they can get away with using the rubber pipe. But you won't get the benefit of hotter water..

Macha

Um...dragging up a thread from 3 years ago as first post to wax lyrical about a product?