questions for solar

canine

Ive had 3 different solar companies call to me and each one tell me contradicting stories ,I honestly believe just like a few years ago when the pellet boilers came into Ireland that they dont know what they,re talking about ,the number of pellet boilers incorrectly installed in this country is huge and I fear that a similar thing could happen with the solar industry .Is there a list of a standard questions I should be asking these guys so I can compare accordingly ,Each company claims that their tubes are more efficient than the others ,they also contradict each other on the required apperture area and cylinder size

jinghong

solar thermal?

Wanna list some of the contradicting stories, maybe we can set you straight

Its fairly simple, nothing to complex.
I saw an evacuated tube panel today on Ebay for £650
heres a kit on done deal
http://www.donedeal.ie/for-sale/buildingmaterials/1179480
probably 2 days work in fitting (500?), so dont pay over the odds

PeteHeat

jinghong wrote: »

solar thermal?

Wanna list some of the contradicting stories, maybe we can set you straight

Its fairly simple, nothing to complex.
I saw an evacuated tube panel today on Ebay for £650
heres a kit on done deal
http://www.donedeal.ie/for-sale/buildingmaterials/1179480
probably 2 days work in fitting (500?), so dont pay over the odds

Honestly I don't know what the O.P. posted to annoy you but it must have been bad to try to pass that kit off on them

Seriously the cylinder looks very like a mild steel one we tested (Made in China), a total waste of money as the insulation made a lagging jacket look high tech and the coils were 1/2" (I could go on).

The solar station and controller are direct from China, while they need a few extra parts in fairness they do work we have one we use for testing panels and no problems.

The average 36 tube heat pipe solar collector would not be sufficient to heat a 300 litre cylinder even a top quality one, most of the honest suppliers would agree with me.

The kit advertised may be suitable for someone looking for a DIY project where they can add more panels in the future, although if I am right about the cylinder it's a waste of time installing it.

Also there is no reference to the product manufacturer or SEIA registered number for grant purposes, even for the person not looking / qualifying for the grant it is nice to know the product meets the minimum standards.

Solar systems should be designed to suit the number of people living in the house and the house itself, no one system has all the answers or suits every home.

There are different types and methods of installation, "In Roof", "On Roof" flat panel, or "Heat Pipe", "U Tube", "CPC" vacuum tubes (and more).

Keep looking until you find the company who answers all your questions even the ones you don't ask, try and find someone independent by that I mean not allied to one product but who can offer a number of options.

BTW there are thousands of wood pellet stoves and boilers performing very well, there were problem systems, suppliers and installers however I doubt there were nearly as many as some media sources like the consumers to believe.

.

jinghong

How can you tell its a mild steel cylinder?
anyway nothing wrong with enamelled mild steel, its used succesfully on the continent for donkeys years. We seem to have a problem with that in the 'british isles'
Hard to tell the spec from the photos, but theres a Wilo pump in the kit, so thats decent at least
I'll bow to your knowledge on the 36 tubes versus 300L

saibhne

jinghong wrote: »

How can you tell its a mild steel cylinder?
anyway nothing wrong with enamelled mild steel, its used succesfully on the continent for donkeys years. We seem to have a problem with that in the 'british isles'

One thing about enamelled steel cylinders is that they're bloody heavy.. it would be a difficult task for two men to carry a 300L version of one of these - couple that with the 300Kg of water it will contain and you need to be sure your floor can hold the weight of this new addition.

Maybe this is why they haven't taken off here..

davidconnors

canine wrote: »

Ive had 3 different solar companies call to me and each one tell me contradicting stories ,I honestly believe just like a few years ago when the pellet boilers came into Ireland that they dont know what they,re talking about ,the number of pellet boilers incorrectly installed in this country is huge and I fear that a similar thing could happen with the solar industry .Is there a list of a standard questions I should be asking these guys so I can compare accordingly ,Each company claims that their tubes are more efficient than the others ,they also contradict each other on the required apperture area and cylinder size

Hello There.. would much prefer the flat panel system as it is more robust. As for apperture area.... You are better off looking at a panel than looking for a panel. Get more than you need... One M2 per person is good. If you fit a 200 or 250lt tank... both are good. I have fitted a <snip> thermodynamic system and find it is even more efficient than regular solar as you can use at night.
Has anyone any feedback? as I'm a convert now.

davidconnors

saibhne wrote: »

One thing about enamelled steel cylinders is that they're bloody heavy.. it would be a difficult task for two men to carry a 300L version of one of these - couple that with the 300Kg of water it will contain and you need to be sure your floor can hold the weight of this new addition.

Maybe this is why they haven't taken off here..

I actually got a 250lt enamelled tank fitted <snip>.
It was heavy but it was lifted by one guy up the stairs so not VERY heavy. Has anyone else had a thermodynamic solar water heating system fitted? I looked into regular solar but they don't do much in the winter.

PeteHeat

jinghong wrote: »

How can you tell its a mild steel cylinder?
anyway nothing wrong with enamelled mild steel, its used succesfully on the continent for donkeys years. We seem to have a problem with that in the 'british isles'
Hard to tell the spec from the photos, but theres a Wilo pump in the kit, so thats decent at least
I'll bow to your knowledge on the 36 tubes versus 300L

Hi,

I am calling it as I see it based on the one we tested, like products manufactured in every country there are good and bad quality, the mild steel one we have is not enamelled and the immersion heater appears to be a death trap.

The standards for cylinders in Ireland are borrowed like many of our standards from the UK where cylinders must comply with WRAS standards which are fairly high especially if the cylinder is pressurised.

The physical size of a hot water cylinder makes it uneconomical to ship all the way from China unless it is very cheap to begin with, also there have been incidents with Chinese stainless steel cylinders as the only way to reduce the cost was to use a much lighter grade of stainless steel.

I have no doubt there are good Chinese products available, the solar station and controller do work and China is the world leader in the manufacture of the evacuated glass tube, in fact many European manufacturers source the tubes from China.

There is nothing wrong with some Chinese heat pipe systems they have been fitted in Ireland for a few years now and when sold honestly the customers tend to be happy with them, in fact we have such a system on test at the moment.

Thermodynamic systems are another type of heat pump using the solar panel as the source of heat instead of the types we are familiar with such as Air to Water or Ground Source heat pumps.

Time will tell if they are as efficient or reliable as claimed, we were looking running a test model but first impression is the cylinder may too big for the average Irish hot press.

.

jinghong

Mate, I get a 'Error occurred: 403 - forbidden' when clicking on your boilers section

Fair enough about unenamelled mild steel tanks, sounds like a disaster waiting to happen

saibhne

davidconnors wrote: »

I actually got a 250lt enamelled tank fitted <snip>.
It was heavy but it was lifted by one guy up the stairs so not VERY heavy.

Strong fella! it took two big mullickers and me to move the last 300Lt enamelled cylinder I came in contact with.. I must eat more weetabix.

quentingargan

canine wrote: »

Ive had 3 different solar companies call to me and each one tell me contradicting stories ,I honestly believe just like a few years ago when the pellet boilers came into Ireland that they dont know what they,re talking about ,the number of pellet boilers incorrectly installed in this country is huge and I fear that a similar thing could happen with the solar industry .Is there a list of a standard questions I should be asking these guys so I can compare accordingly ,Each company claims that their tubes are more efficient than the others ,they also contradict each other on the required apperture area and cylinder size

Yes, you can ask some specific questions to help you get an appropriate deal;

Zero loss efficiency and heat loss coefficient
Ask for a copy of the EN2975 certificate for the panel (and if you go ahead and buy, make sure the brand and model are the same as on the cert). This will give you three figures - zero loss efficiency (the noon efficiency of the panel), Heat loss coefficient (the rate at which the panel will lose heat as it warms up, usually higher for flatplates, lower for tubes) and IAM, a range of figures by which the efficiency shoudl be multiplied as the sun moves away from noon (flatplates will fall off either side of noon, but the twin wall tubes have an increasing figure as you move from noon)

This will all give you some idea of the actual efficiency of the panel itself

Aperture area to cylinder size
We'll take it as a given that the cylinder is certified for UK and Ireland. If not, slam the door! This ratio can vary - if you don't have hard water (limescale) you can bring the cylinder up to 85 degrees safely, so a higher ratio might be appropriate. If they haven't asked you about limescale, they shouldn't be selling a system with too high a ratio, particularly for tubes.

Heat Dump
Do they include a heat dump? Most suppliers don't, but this is changing. A heat dump takes care of excess heat when you go on holidays, preventing the system from going into stagnation. Stagnation degrades antifreeze, damages pipe insulation, and puts huge pressure on the plumbing - usually at a time when you are on the beach somewhere...

Reference Sites
See if you can talk to satisfied customers. Make sure it isn't the missus...

Household use
The salesperson should be asking you about how many people are in the house and the nature of your hot water use. For example, your demand and cylinder size might alter if the house is always occupied during the day.

PeteHeat

jinghong wrote: »

Mate, I get a 'Error occurred: 403 - forbidden' when clicking on your boilers section

Fair enough about unenamelled mild steel tanks, sounds like a disaster waiting to happen

Thank you site fixed ( I hope), appreciate you pointing it out.

.