Solar Vacum Hot water & UFH system

RedLady

Hi,

Sufacepower.com in Mayo have just launced a new system for DHW and UFH. They state that this system (which costs 10,000) will supply 70 % of your Hot Water needs and up to 90% of your UFH needs. If this is true, it sounds a much better deal than going down the Geothermal router.

Anybody have any thoughts on such a system?

Regards,

RedLady

CJhaughey

Sounds good until you figure that your max heating requirements are in winter, winter has short daylight hours and the amount of bright light will likely be minimal.
I know that Evacuated tubes are more efficient than Flat Plate collectors however they are not efficient enough to run UFH unless you have a huge collection area.
You will also need to have a good south facing aspect for the tubes and no planning issues:rolleyes:
You will also have a huge surplus of hot water in the summer, nice but also problematic to get rid of.
One Caveat, ask them where exactly the tubes come from and how long is the guarantee.
I have heard of a lot of chinese made tubes coming onto the market at a cheap price, and with these systems quality is everything.
There is more info on some of the threads in Green issues.

Johnee

Thanks for posting that Red Lady. Im looking at options for UFH myself at the moment and, for reasons of space and granite ground, geothermal isnt an option.

CJ - what about if you put a system in place with solar panels and a wood pellet stove? Would there be problems with that? Surely you should be able to get a relatively small back-up stove, which would mean you wouldnt have to use the stove a lot and therefore would avoid the problem of having enough storage space for pellets that Ive seen other posters mention.

CJhaughey

I am sure that a suitable solution could be found with a solar panel and a wood pellet stove but realistically why would you have the two?
My reasoning was that I have 6.2m2 of flat plate feeding a 400 litre tank for DHW.
Completely separate I have a small wood burner for heating, I also have a small 5kw electric underfloor heating system.
however the critical thing that you must remember is that all these systems are dependant on having a well insulated and airtight house from the start.
I would say that you should look at a heat recovery ventilation system before looking at all the other heat sources.
IF a house is built to the right spec it can be made passive or very nearly passive,That way you would not need a huge heat source, a small amount of heat will do, in conjunction with a way of recycling heat that is already in the house.

twenty8

A friend of mine recently did his thesis on alternative forms of heating - I am still trying to get a copy of it!!

But one of the things that he said to me was to watch the marketing blurb from the solar companies. It is true that it can provide 70% of your total heating requirements but you have to consider the actual truth.

If a home needs 10,000 litres of hot water / year (no idea if that is accurate - just an eg) then solar can provide 7,000 litres. However - it cannot provide you with that water when you want it - ie winter. The majority of that would be provided during the summer when you don't need it.

CJhaughey

Not entirely sure that you don't need hot water in the summer, I find that I sweat a lot more in the summer and wash more clothes because of all the outdoor activity.
If you look at most water usage patterns the majority of water is used during the summer.
Showers and washing clothes will use a good part of the 400L I am sure.

RedLady

Hi,

Just to answer a couple of the questions you asked
The solar panels are German made. There is a 5 year guarantee with them.
They are CE rated so they have had to gone through saftey tests.
They have pressure release valves and a waste pipe so that if there is too much hot water in the tanks - it has somewhere to go.
They are super conducting so in theory they should perform very well. They have a contrel sysetm which can be programmed in various ways i.e. if u dont want your UFH tank water heated and only the DHW for example on a hot summer day.
The big problem that I can see initially is that it is new to the market and has not been installed yet to any large degree so there is no one out there to give any real feedback on it yet.I do know that they are installing it in a house in Donegal during the week and a production crew are filming it for RTE .

Regards,

Redlady

rooferPete

Hi Red Lady,

I have been trying to find a quality Solar system because I am being asked for it, many that held the UK grant Clear Skies approval were 1980's technology dressed up.

CE marking means very little if anything, it does not require independant testing similar to a BBA cert, or the Irish Agrement cert.

Perhaps they are using a system similar to photovoltaic that works on UV instead of direct sun light ?

It will make for a very interesting programme on RTE and maybe help raising the standards that other manufacturers have to work to.

Johnee,

There are tanks available for Pellet Fuel, it is even possible to build your own

.

RedLady

Hi,

Yes, they seem to be using that type of technology - UV light as opposed to direct sunlight. They will have more information on their website after the weekend as they are launching the product at a show in Belfast this week.

Regards.

CJhaughey

Looks like they are just bog standard Evacuated tubes to me.
They are a lot more efficient than flatplate collectors but they do not use UV light, the copper pipe inside the tube is in a vacuum which as we all know allows the fluid to boil easily.the heat rises and heats a copper bulb at the top of the tube which in turn heats the water/heat fluid.
It is a good system but I would make absolutely certain that the tubes are top quality. The critical point of most vacuum tube is where the bulb seals to the glass, two different materials and consequently differing rates of expansion/contraction.

bren96

Hi

Has anyone dealt with surfacepower.com or does anyone have any up to date info on installing UFH that is fed by evacuated solar tubes?

Bren