Hot Water Cylinder / Solar Water

naturals

I've just bought a new house and want to install a solar water heater later in the year.

I'm currently remodelling the bathroom which involves moving the hot water cylinder. This is a manky old thing so I want to upgrade to a new cylinder that will be suitable for fitting to a shiny solar water heater. I know this requires a dual coil cylinder - my question is whether I'll also be able to fit a stove to this to heat water during the winter months?

I'm hoping you'll tell me I can fit the two (solar and stove) in a parallel arrangement with a Y joint to feed both through the cylinder. I guess I can then shut the stove off during the summer to prevent the pump feeding cold water through the cylinder and visa versa during the winter.

We currently have a gas boiler providing the bulk of the hot water with an immersion heater as backup.

Any thoughts very gratefully received!

Mr_Proctalgia

Not sure exactly what you mean, do you intend to have a CH boiler, Solar and solid fuel or just Solar and solid fuel?

If the latter then a twin coil tank will suffice - The lower coil being used for solar and the upper for the stove. If you intend to use 3 supplies it may be possible to use a heat store instead, although you can get 3 coil tanks - but you'll pay for it. I would suggest that you NEVER have a means of closing off primary heating pipes in case you make a bomb, or get a boil up.


The is loads of info on the web so get Googling. LOL

kestor

buy a cylinder with a solar coil as th heat transfer is alot more efficent due to the solar coil having mor than twice te suface area solar cylinders come with twin coils as standard but can also have a thermal store coil fitted to give you mains presure hot water from a vented cylinder.
hope this helps jason
ps solar controlers are clever bits of kit and will sort out your arangement

naturals

Thanks for the replies - so quick!

Kestor - I'm think I remember reading you've already installed a system. Would it be possible to feed a solar panel and a stove into a solar controller and trick it into thinking it has two solar panels plumbed in or do they only accept one pipe in?

Proctalgia - not sure about whether to keep the boiler or not. It looks fairly new so it seems silly not to keep it as a backup. You seem to know your onions, what would you think best?

Mr_Proctalgia

I am several weeks into planning a system for a new home I'm getting. A solar cylinder should be tall and narrow to help keep the water stratified and it also wants to be BIG as big as you can fit. The lower solar coil has to get every last drop of heat from the circulating solar water and so is very long and finned, a solar panel cannot heat up water that is already hot. The other options are whether or not to go for a sealed system or a drain back system and the careful choice of pump (its like leaving the light on all day) You will definately need a Differential controller (Delta Controller) to turn things on and off. As far as keeping your boiler - Why not you will need to have 2 extra bosses tapped into the cylinder and another pump and plate plate heat exchanger - running backwards as it were, so you can pump the potable water through the heat exhanger.

I am leaning towards the drain back system because it is simple, unpressurised, no need for anti freeze but it is noisy so I'm thinking outside my box on that one - I have one idea I shall test out when I get sorted out.

ariba10

You could have two hot water cylinders with one feeding the other. The first one on the solar panel prewarming the water for the second.

kestor

naturals
the solar cylinder has at least two coils one for heating via the solar collactor and the other from a means of your choice ether a boiler or a wood burner ect.
the solar controler takes different temperatures from different sources so when the collector temp is higher than the cylinder coil the circulation pump operates and warms up the cylinder
i will dig out the instuctions from the controler and ether send you a copy or try to email you a copy.this will explain all you need to know a lot better than i can explain it.
kind regards jason

lineman_2

http://www.solartwin.com/index.htm

Check this link.

naturals

Right guys, I'm a step closer to getting my solar system off the ground. I've found a cheap cylinder, now I need some guidance on a controller. What is the difference (aside appearance) of the £50 ones and the £200+ ones. Is it worth getting a decent one or will a basic suffice?

Skiduck

naturals wrote:

Right guys, I'm a step closer to getting my solar system off the ground. I've found a cheap cylinder, now I need some guidance on a controller. What is the difference (aside appearance) of the £50 ones and the £200+ ones. Is it worth getting a decent one or will a basic suffice?

What are the two you are looking at? do you have any links?

billbrooks

the twin coil solar cylinder has a sensor in the bottom of it and the solar collector has a sensor in the flow side. When the sensor in the solar collector is 6 degrees higher than thehot water cylinder the resol unit will turn on the pump and drive the heated fluid to the coil in the bottom of the cylinder occasionally the resol unit will allo the temperature to rise to 65 degrees to kill off legionaires deisease. for more information [EMAIL="info@aztec-solar-water-heating.com"]info@aztec-solar-water-heating.com[/EMAIL]