Can a solar panel help to heat rads aswell??

paddy147

Can a solar panel setup help to heat water in radiators aswell as providing domestic hot water.

How hard would it be to do,if its possible?

Thinking very long and hard now about getting a solar panel system to have hot water in plentyfull supply and cut down on the gas usage.

Heating the rads up,even a bit,would be a huge bonus too,if its possible.

kscobie

not worth the hassle, when its warm and sunny , you will have lots of heating, and when its cold and dull, ie, when you want heat, you will have none.;)

paddy147

kscobie wrote: »

not worth the hassle, when its warm and sunny , you will have lots of heating, and when its cold and dull, ie, when you want heat, you will have none.;)

I dont get it???.as there are solar systems that work without sunlight,so when its cold and dull......then yes,I will want heat,naturally.

Thats what Im asking,can a solar panel system provide some heating of the radators too??

heinbloed

Of course you can heat a home with ST energy, it is done anyhow - want it or not. The (thermal) energy purchased to keep a home at + 20 degrees Celsius is only about 2 % of it's demand, the other 98% is for free. From the sun.
The thermal energy demand decides on the economics of these 2 %. Not the plumbers opinion.

championc

paddy147 wrote: »

Can a solar panel setup help to heat water in radiators aswell as providing domestic hot water.

How hard would it be to do,if its possible?

Thinking very long and hard now about getting a solar panel system to have hot water in plentyfull supply and cut down on the gas usage.

Heating the rads up,even a bit,would be a huge bonus too,if its possible.

Hi Paddy

This possibly would be better in the Renewable Energies Forum so maybe a mod will move it. In any case, here's my opinions. First off, Solar Panels will generate Electricity whereas I assume you are thinking about a Solar Evacuated Tube system which heats a store of water indirectly via a coil.

As kscobie says, Evacuated Tubes produce their heat when we have plenty of sunshine. The problem with this is that most of your hot water will be generated during the summer - the time most likely when you won't be running your heating anyway. In addition, to transfer heat from a Solar store into a coil to then heat your rad water, the solar store would need to be quite hot.

So the thing to do is firstly think about how you would see a system fitting into your home. From my experience, rather than focusing on how to use up your water in as many ways as possible, look instead at how you are heating water now and see about you can reduce the cost of heating this water. Even if you heat water indirectly using a coil from your Central Heating, that's still cooling your central heating water which you'll need to heat in the boiler so this costs. Or maybe you just use Electricity via an immersion.

I have had a system for a year now. I have a Combi Boiler which heats water instantaneously as water is required. So if I had hot water in the store, it just bypassed the boiler straight to the tap. If store water was luke warm, the water would be passed back to the boiler to be heated to the desired temperature. So heating luke warm water instead of rising main cold water.

Assuming you have a standard heating system with an immersion, a solar store could possibly replace this traditional cylinder (maybe the cylinder could be used for the store - I don't know). So the solar could heat the water and if your cylinder is heated by the Central Heating, a diverter valve could then block taking heat from the Central Heating if the store has been heated by the sun, this would save money. And on cloudy days / Winter, the Central Heating would just the water as it does now.

With an anti scald valve, it mixes down any hot water above scalding point with cold water to give hot waqter just below scalding level. The will stop the wasting of large amounts of your precious hot water if all you are doing is using put hot and mixing at the taps with water from a cold tap.

Hope this helps. I reckon my gas consumption is down about 10 per cent. I reckoned that payback would be about 10 years and things are heading that way I think (not taking into account any rises in fuel costs)

paddy147

championc wrote: »

Hi Paddy

This possibly would be better in the Renewable Energies Forum so maybe a mod will move it. In any case, here's my opinions. First off, Solar Panels will generate Electricity whereas I assume you are thinking about a Solar Evacuated Tube system which heats a store of water indirectly via a coil.

As kscobie says, Evacuated Tubes produce their heat when we have plenty of sunshine. The problem with this is that most of your hot water will be generated during the summer - the time most likely when you won't be running your heating anyway. In addition, to transfer heat from a Solar store into a coil to then heat your rad water, the solar store would need to be quite hot.

So the thing to do is firstly think about how you would see a system fitting into your home. From my experience, rather than focusing on how to use up your water in as many ways as possible, look instead at how you are heating water now and see about you can reduce the cost of heating this water. Even if you heat water indirectly using a coil from your Central Heating, that's still cooling your central heating water which you'll need to heat in the boiler so this costs. Or maybe you just use Electricity via an immersion.

I have had a system for a year now. I have a Combi Boiler which heats water instantaneously as water is required. So if I had hot water in the store, it just bypassed the boiler straight to the tap. If store water was luke warm, the water would be passed back to the boiler to be heated to the desired temperature. So heating luke warm water instead of rising main cold water.

Assuming you have a standard heating system with an immersion, a solar store could possibly replace this traditional cylinder (maybe the cylinder could be used for the store - I don't know). So the solar could heat the water and if your cylinder is heated by the Central Heating, a diverter valve could then block taking heat from the Central Heating if the store has been heated by the sun, this would save money. And on cloudy days / Winter, the Central Heating would just the water as it does now.

With an anti scald valve, it mixes down any hot water above scalding point with cold water to give hot waqter just below scalding level. The will stop the wasting of large amounts of your precious hot water if all you are doing is using put hot and mixing at the taps with water from a cold tap.

Hope this helps. I reckon my gas consumption is down about 10 per cent. I reckoned that payback would be about 10 years and things are heading that way I think (not taking into account any rises in fuel costs)

Im barred from construction section,as I had a run in with a moderator,as he didnt like a genuine and legitimit post of mine.


hense me asking here in the plumbing and heating section.

Thanks for the advice.

heinbloed

The term "solar panel" isn't defined.
Are you looking at solar thermal collectors or photovoltaic panels?

Both can be done, thousands of samples around the globe. Or mine in Cork. Another here in Ireland being build at the moment.

The space heating supply is a legal requirement in some countries if asking for subsidies when installing a solar thermal system. For example in Germany and parts of Switzerland.
Suppporting the standard domestic hot water demand with ST collectors isn't worth the investment in the very most cases. The primary energy input in such a toy installation plus running costs including maintenance is higher than any economic calculation justifies.

Ask a heating engineer to figure out the demand, the available surfaces for the collectors and he/she will tell you how much of the total thermal demand can be covered.
There are EN standards as well as ISO methods to figure out the demand/coverage.
Most larger ST manufacturers/energy advosors offer basic calculations for free or a small fee on-line.

Joey the lips

No. Not in ireland.

Plombier

Can a solar panel setup help to heat water in radiators aswell as providing domestic hot water.

Yes of course it can but it will depend on the installation and how well the control system is implemented.

championc

Of course, but is it really worth all the effort, cost and potential gains. The only time I personally could see a need for heating at home during the summer is maybe the last hour or so at night. But I suppose there are many factors like the aspect of the house itself. I'm lucky in that the rear of the house faces exactly due south. We have large 8' x 4' windows which allow plenty of sunshine in during the summer and we also have a conservatory and there are days when that can draw in a huge amount of heat.

I'm no expert but I would think your Store water would need to be in excess of 60 deg C to be able to transfer a sufficient amount of heat into your rads circuit to deliver heat into your home. The difficulty with doing what you want is basically that you would need to obviously link your rads circuit to your store but then you would also need to install a pump and then I think some form of valve to bypass your boiler (since your boiler will be kept switched off). Of course some experts could maybe mess with a boiler to run the pump but not fire the boiler (maybe an expert on here could confirm if this is possible). If this cannot be done and a separate pump is required, would the boiler need some form of bypass piping ?

Anyone out there actually doing it and feel it's a worthwhile addition ? Someone might talk me into doing it yet !!


C

Joey the lips

I have to say.... I have left it for someone to state the obvious and it has not happened.....

If its sunny or warm enough for a solar panel to generate enough heat to heat a house chances are the tamp outside is warm enough not to need heat inside. Granted solar panels do not need temp but sun....when is this likely to be long enough in ireland to justify solar.

But yes interesting discussion

championc

Sounds like you were busy typing when I posted my two pence worth. For me, I could maybe do with something for the last hour in the evenings during the summer

Joey the lips

championc wrote: »

Sounds like you were busy typing when I posted my two pence worth. For me, I could maybe do with something for the last hour in the evenings during the summer

No i had been reading that as well. Just did not want to focus on the fact that you would have the most expensive heating system ever with no chance of recoverimg cost.

The problem with storing heating water and then looking at transfering the heat is there is a massive amount of heat loss. Even a standard heating sircuit looses a terriable amount through the cylinder. The principle of heating at the moment is Temperature and pressure which makes it more efficent and why an open system is a very poor performer.

But just in case i seem it my comments are ment in jest as i love a bit of open thinking really

esox28

I have successfully installed 4 solar boosted central heating systems, using a buffer tank in tank cylinder. the basic the tank has a 500ltr buffer and a 200ltr d hot water cylinder sitting in the top of buffer so when the buffer is heated the hot water is indirectly heated as is is at the hottest part of tank.

the tank has 6 input tapping connections 2 for an oil / gas boiler and 2 for a multi fuel stove. also a solar thermal coil tapping's at bottom of tank.

the tank also has 4 output connections 2 for rads and 2 for underfloor-heating.

your oil boiler is thermostatically interlinked to the buffer so when any other heat is inputting and satisficing the demand the oil boiler wont even fire up. the solar collectors are sized to meet the demand of total heating and domestic hot water demand, usually 12m * of flat panel for this example. ok this solar system will never meet the dec/ jan demand of heat input but it will decrease your oil consumption.

there are a few other benefits to installing this tank, your condensing boiler will run at max efficiency with the buffer as you will nearly always have a 20*c temp differential between flow and return.

Plombier

The average winter temperature in Ireland is around 5.0C
At 5.0C a heating system with good controls will have a
return temperature of 38.0C as long as the solar input is
above this temperature it will contribute to the system.

A 1000 liter buffer lowered from 70C to 30C will contribute
46 Kwh to the system so a solar contribution is a real option
if your installer knows what he is doing.

If you apply this to a low temperature heating system (UFH) then
the advantages are even greater.

Temperatures with outdoor reset control.

Outside Air_____Flow_____Return
20.0__________20.0______20.0
17.5__________25.0______23.0
15.0__________30.0______26.0
12.5__________35.0______29.0
10.0__________40.0______32.0
07.5__________45.0______35.0
05.0__________50.0______38.0
02.5__________55.0______41.0
00.0__________60.0______44.0
-2.5__________55.0______47.0
-5.0__________70.0______50.0

championc

Joey the lips wrote: »

The problem with storing heating water and then looking at transferring the heat is there is a massive amount of heat loss. Even a standard heating circuit looses a terrible amount through the cylinder. The principle of heating at the moment is Temperature and pressure which makes it more efficient and why an open system is a very poor performer.

Hi Joey

I have a Combi boiler so I have a sealed pressurized system. My store only looses about 1 deg C every 3 hours. It's a 180L Range Tribune Twin Coil Cylinder which appears to be very highly insulated.

Given the replies from Esox28 and Plombier, maybe it's starting to look more and more of a runner than I originally thought. I have the spare coil so it's just linking this to the rads return circuit. Since I have just rads (No UFH) could I simply stick a pump onto the flow or return going to the Store ? And would \i need to do some sort of boiler bypass or would my new pump circulate the water around the system and through the boiler and spin the boiler pump since the boiler will be off (my Combi has everything in the case - including the pump) ?



C

yoshytoshy

What about a wind turbine feeding an immersion ,could the same thing be applied to an electric immersion supplying heat to the cylinder in colder weather ?

Find this fascinating ,I only install gas boilers myself.

get_d_hand_in

No its not economical. Solar thermal panels are the one that provide hot water. These are the ones that are most economical to install in Ireland for various reason including the grant awarded for the. Photovoltaic (PV) generate electricity, these are not economical in Ireland, also no grant for them,

Anyhow Solar thermal panels ( evacuated or not ) are not very useful during the winter when you want to heat the radiator. To install a efficient system, you want to have exactly enough heat been provided during the summer and thus not wastage, by achieving this you will not have enough heat during the winter and will need to provide this energy externally.

get_d_hand_in

yoshytoshy wrote: »

What about a wind turbine feeding an immersion ,could the same thing be applied to an electric immersion supplying heat to the cylinder in colder weather ?

Find this fascinating ,I only install gas boilers myself.

Yes you could, but wonder what the outlay costs would be and thus the return period. I find that during the winter, there is an abundance of hot water in the house from the central heating thus solar thermal are pretty useful as i dont need the immersion during the summer months

heinbloed

The OP did ask :

Can a solar panel setup help to heat water in radiators aswell as providing domestic hot water.

The answer is a clear: Yes.

That thermal energy gets 'lost' when storing it is propably not necessary to explain to the OP, I think ...

Lost ST thermal energy costs nothing. That's obviously new to some posters here. There are no costs involved when loosing something that comes for free.
Or to put it into an energetic amateur's picture: The radiation energy from the sun hitting the house would be lost anyhow. After warming up the walls, the room. Nothing last for ever. But 1 form of energy comes for free: solar radiation.
All other forms of thermal energy have to be paid for.

And for those guessing how much there is to be picked up for free there is a better, more acurate method: calculate it!

Here is a very valuable tool:

http://re.jrc.ec.europa.eu/pvgis/

Note that the sun shines now 30 % more in winter compared to previous statistics.

So all installed ST systems should produce 30 % more valuable thermal energy than previously calculated.
I can imagine our specialists' work never actually delivered what was PREVIOUSLY calculated. Right?

And now the new weather data, illuminating the dark side of the installer trade.


ChampionC has a good question as well:

Given the replies from Esox28 and Plombier, maybe it's starting to look more and more of a runner than I originally thought. I have the spare coil so it's just linking this to the rads return circuit. Since I have just rads (No UFH) could I simply stick a pump onto the flow or return going to the Store ? And would \i need to do some sort of boiler bypass or would my new pump circulate the water around the system and through the boiler and spin the boiler pump since the boiler will be off (my Combi has everything in the case - including the pump) ?

As long as your storage tank has enough temperature to deliver anything usefull, use it.
Turn down the temperature setting at the boiler to zero. Or as low as possible (smiley). And then turn the heating system on. The boiler won't kick in until the return temperature falls below the set temperature.
By this method the boiler's pump will empty the thermal storage, distributing the thermal energy into the radiator.
No need to ad another circulation pump. If some plumber want's do that: send him away.
Central heating with 1 central circulation pump can be done, is done already in many Irish homes. On the continent that is the general method.

B.t.w. : a radiator is a radiating thing. The term 'radiator' is not limited to the wall hung metall container holding water. The surface of a toilet cystern for example is radiating as well. Any surface emitting radiation is a radiator. A house wall, a floor slab etc....

paddy147

heinbloed wrote: »

The OP did ask :



The answer is a clear: Yes.

That thermal energy gets 'lost' when storing it is propably not necessary to explain to the OP, I think ...

THANKYOU.

A simple answer that even I can understand.:)

championc

Firstly a note for yoshytoshy, A Wind Turbine might generate 400w at 12v DC but this is not 400w of AC and so, you'd need multiples of these to get 400w of 240v AC. Same also goes for Solar Electric Panels so this is why there is still no real payback over their lifetime

Thanks heinbloed
I have one small problem if I want to link my Store to the CH return pipe. My upstairs is zoned off so I would need to tap into the CH return near the boiler. The Store is in the attic while the Boiler is in the kitchen so my guess is about 10m up to the Store and 10m back again to the boiler. No point in tapping into upstairs since nothing would happen if zone closed off and during the summer, I'd only trickle heat into downstairs too.

I can do all work myself so cost is just piping. I would use Qual-Pex Eco-Duo but is it all worth the effort ? Is heat loss lower when water is moving through a system as opposed to lying stagnant ?

However, a setup like this could allow me to heat my Store using the CH Return during the winter - transferring heat into the store rather than drawing out in Summer.

yoshytoshy

championc wrote: »

Firstly a note for yoshytoshy, A Wind Turbine might generate 400w at 12v DC but this is not 400w of AC and so, you'd need multiples of these to get 400w of 240v AC. Same also goes for Solar Electric Panels so this is why there is still no real payback over their lifetime

Thanks for that ,I wasn't aware of any output figures.
I certainly didn't think it was that low.

heinbloed

Championc asks:

I would use Qual-Pex Eco-Duo but is it all worth the effort ? Is heat loss lower when water is moving through a system as opposed to lying stagnant ?

I don't know if this pipe is suitable, contact the manufacturer. It should be pressure proof, diffusion tight and heat resistant. Standard CH pipe. And well insulated of course.

The heat is 'better' lost when circulating the water, passive (thermosyphoning) or pumped.

If it is worth the effort, the expenses? Who knows, a heating engineer will figure you out the numbers.

Fraunhofer ISE ( a reputeable organisation, google) has figured out for the German consumer magazine Oekotest recently 17 so called " heating suporting solar thermal systems ". These are complete ST packages, systems off-the-rail. Most of the companies who's products had been researched are trading in Ireland, have one or more representatives here.

Here the report, an abstract in German language:

http://www.sonnewindwaerme.de/sww/pdf/solarwaerme/0406-SWW_1510_062-063_Thermie_Systemvergleich.pdf

I tried " google translate" , but as usual one has to use plenty of phantasy:

http://translate.google.ie/translate?js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&sl=auto&tl=en&u=http%3A%2F%2Fwww.sonnewindwaerme.de%2Fsww%2Fpdf%2Fsolarwaerme%2F0406-SWW_1510_062-063_Thermie_Systemvergleich.pdf

So I summarise:

All offered Systems supplied more than 20% of the demanded (calculated!) thermal energy to two standardised buildings (single family homes, detached) in two different towns, Essen and Passau.

From the economical point of view the simulation showed the system from Solarfocus ( bussy here in Ireland ! ) to be the best player, in 20 years the system has saved twice it's price in primary energy costs. This price is for the system (collectors, storage, pump/control, plumbing etc.) plus installation work.

Now comes the Irish seller/installer .... can't be done in Ireland etc. .... "Can't" because of incompetence !

ALL of the 17 researched packages systems showed an ammortisation within 20 years. But Solarfocus was the winner in ammortisation. For documentation ( installation guide) they were about the worst !

So a good plumber can build an economical St system supporting central heating. But an amateur trying to do so needs help.


Other manufacturers were more expensive (still within the 20 year pay-back period) but had better documentation.

Here I see a very weak point in the Irish installers trade, they don't have the intellectual back-up to get a cheap system running economical. They fudge it up to the worst, neither understanding the laws of physics nor having much experience, no documentation available and if so ( with the more expensive systems) they don't understand it.

If 10 meters of pipe is all that you need, do it.
You wouldn't need the most expensive,thick insulated district heating pipes. My guess work is around € 100.- for the material incl. good insulation.
What you might need is a gravity valve, one that cuts-off the unwanted circulation of the water (when the storage tank is cold but the CH is warm). But this depends on the overall layout.

Good luck with it !

PS

Here the direct link to the published ST system test (page 140-149)

https://shop.oekotest.de/cgi/epaper.cgi?heftnr=M1010;ak=si;elink=http%3a%2f%2fwww.wai.de%2fw%2fdetails2_oko.asp%3freferer%3dokotestkiosk%26ind%3d210962244%26tab%3dE%26owner%3d21646%26rowid%3d0%26sort%3dX%26atab%3dM%26Frame%3d1%26MagID%3dM1010%0D

championc

Qual-Pex Eco-Duo is twin Pre-insulated qual-pex


It's also OK for high temps

get_d_hand_in

heinbloed wrote: »

The OP did ask :



The answer is a clear: Yes.

That thermal energy gets 'lost' when storing it is propably not necessary to explain to the OP, I think ...

Lost ST thermal energy costs nothing. That's obviously new to some posters here. There are no costs involved when loosing something that comes for free.
Or to put it into an energetic amateur's picture: The radiation energy from the sun hitting the house would be lost anyhow. After warming up the walls, the room. Nothing last for ever. But 1 form of energy comes for free: solar radiation.
All other forms of thermal energy have to be paid for.

And for those guessing how much there is to be picked up for free there is a better, more acurate method: calculate it!

Here is a very valuable tool:

http://re.jrc.ec.europa.eu/pvgis/

Note that the sun shines now 30 % more in winter compared to previous statistics.

So all installed ST systems should produce 30 % more valuable thermal energy than previously calculated.
I can imagine our specialists' work never actually delivered what was PREVIOUSLY calculated. Right?

And now the new weather data, illuminating the dark side of the installer trade.


ChampionC has a good question as well:


As long as your storage tank has enough temperature to deliver anything usefull, use it.
Turn down the temperature setting at the boiler to zero. Or as low as possible (smiley). And then turn the heating system on. The boiler won't kick in until the return temperature falls below the set temperature.
By this method the boiler's pump will empty the thermal storage, distributing the thermal energy into the radiator.
No need to ad another circulation pump. If some plumber want's do that: send him away.
Central heating with 1 central circulation pump can be done, is done already in many Irish homes. On the continent that is the general method.

B.t.w. : a radiator is a radiating thing. The term 'radiator' is not limited to the wall hung metall container holding water. The surface of a toilet cystern for example is radiating as well. Any surface emitting radiation is a radiator. A house wall, a floor slab etc....

I'm sorry but its not a clear yes. Its nor economical unless you have an abundance of money that you want to spend on this system that probably wont pay itself back in your lifetime.

There are costs involved in loosing something that comes for free. It cost to harness the suns energy. So why harness it if your just going to waste it by sending it off to heat sump or the likes.

heinbloed

A commentator wrote:

I'm sorry but its not a clear yes. Its nor economical unless you have an abundance of money that you want to spend on this system that probably wont pay itself back in your lifetime.

There are no genuine calculations available to prove that I suppose, just guess work as usual, based on ignorance I'd say .....
Experience show that ST systems are economical for space heating. The Danish company Arcon offers ST energy for a price of € 0.03-0.04 per kWh.Delivered and metered.
Ask your heating system installer to guarantee the price of actually used thermal energy per kwh. If he/she says they can't shop somewhere else.

Economical, metered ST heating system's live data here:

http://www.solar-district-heating.eu/

Here is a tool that can be used to check the economical performance of a ST installation:

http://www.trnsys.com/

heinbloed

A commentator wrote:

I'm sorry but its not a clear yes. Its nor economical unless you have an abundance of money that you want to spend on this system that probably wont pay itself back in your lifetime.

There are no genuine calculations available to prove that I suppose, just guess work as usual, based on ignorance I'd say .....
Experience show that ST systems are economical for space heating. The Danish company Arcon offers ST energy for a price of € 0.03-0.04 per kWh.Delivered and metered.
Ask your heating system installer to guarantee the price of thermal energy per kwh. If he/she says they can't shop somewhere else.

Economical, metered ST heating system's live data here:

http://www.solar-district-heating.eu/

Here is a tool that can be used to check the economical performance of a ST installation:

http://www.trnsys.com/

get_d_hand_in

heinbloed wrote: »

A commentator wrote:


There are no genuine calculations available to prove that I suppose, just guess work as usual, based on ignorance I'd say .....
Experience show that ST systems are economical for space heating. The Danish company Arcon offers ST energy for a price of € 0.03-0.04 per kWh.Delivered and metered.
Ask your heating system installer to guarantee the price of thermal energy per kwh. If he/she says they can't shop somewhere else.

Economical, metered ST heating system's live data here:

http://www.solar-district-heating.eu/

Here is a tool that can be used to check the economical performance of a ST installation:

http://www.trnsys.com/

Jayjus thats very interesting stuff alri, i'm basing my analysis on a once off installation for a single home which i'm presuming the OP was talking about which is not economical.

There are calculations to calculate the efficiency of a system depending on its position, orientation, model being used and end energy usage.

Maybe Ireland should put some a those green field NAMA sites to good use and build one of these power stations if the figures add up.

esox28

championc wrote: »

Qual-Pex Eco-Duo is twin Pre-insulated qual-pex


It's also OK for high temps

from wot i can gather you have a combi oil boiler and an additional domestic hot water store in attic space heated by solar with a spare coil half way up the side of the tank and you want to dump some of the excess heat into your ch systems..ok so far?

I'.m guessing your boiler is not connected to this store. so the most efficient way of connection this to ch is by treating it like any other additional heat source put a non-return valve on the flow of boiler and connect the flow of cylinder into this line after the nrv also put a nrv on the flow coming from the cylinder and connect your returns in this way each heat source will not inter-fear with each other.

to deliver the heat from the store you will need a circulating pump on the flow pipe ( doesn't really matter flow/return in pressurised system) the best way of controlling this pump is to connect power to a thermostat on the store which sends power to a room stat which in turn sends power to the circulating pump. this will give optimum control so if there is no heat in the store and the room stat is calling the cir pump wont be running needlessly.

btw: you wont need the duo piping when installing inside the house this piping runs @ bout €45/mtr, try and keep costs to a min as this set up wont generate huge amounts of heat when you need it.

yoshytoshy

OFF topic ,but thought it would be of interest to people here.
Baxi have a gas boiler that generates 1KW of electricity ,by using a minimal amount of gas.

https://www.youtube.com/watch?v=JpV1w65GSdo

Joey the lips

yoshytoshy wrote: »

What about a wind turbine feeding an immersion ,could the same thing be applied to an electric immersion supplying heat to the cylinder in colder weather ?

Find this fascinating ,I only install gas boilers myself.

There is an interesting thread in the renewables search that actually asks this. The "women" in question asks how it can be done. There is a lot of reasons explained how it should be done but there is also a lot of general information suppied on why economically you would take at least 30 years to make your money back.

The orig op then goes on to ask why the electricity cannot be sold onto the ESB. its then established through the article that the ESB would not find it viable to download wind energy from single houses.

The article then asked why the turbine could not power the house through the day and return to the grid at night. The same arguement of economic viability is given.

i have sold wind turbines. tbh I am not convinced that they are worth while. They require there own post sunk deep in the ground. They will shake a house apart if screwed to the side. They do not produce enough to justifty the money and the maintenance usually requires disassembly which is not an easy tanks.

I also have reservations about solar however to meet the greens requirements it is the cheapest solution on the market.

For my money i think a lot of the future will be in "smart energy" ie There is storage heaters on the market at the moment that consume energy for 15min but heat for 3 hours Granted for a small room like a bathroom these currently cost 600 euro but thats guaranteed heat. I think eventually internal rooms in homes should be room sealed with external one way vents bringing in and taking out air. This way rooms used will only be heated.

Water should be pressurised and heating on demand.

This ability is hear now... just waiting on the greens to realise that renewables are not the be all they think.

championc

esox28 wrote: »

from wot i can gather you have a combi oil boiler and an additional domestic hot water store in attic space heated by solar with a spare coil half way up the side of the tank and you want to dump some of the excess heat into your ch systems..ok so far?

Correct - although the boiler is Gas - a Vaillant 824E

esox28 wrote: »

I'.m guessing your boiler is not connected to this store. so the most efficient way of connection this to ch is by treating it like any other additional heat source put a non-return valve on the flow of boiler and connect the flow of cylinder into this line after the nrv also put a nrv on the flow coming from the cylinder and connect your returns in this way each heat source will not inter-fear with each other.

to deliver the heat from the store you will need a circulating pump on the flow pipe ( doesn't really matter flow/return in pressurised system) the best way of controlling this pump is to connect power to a thermostat on the store which sends power to a room stat which in turn sends power to the circulating pump. this will give optimum control so if there is no heat in the store and the room stat is calling the cir pump wont be running needlessly.

I'll think between this method and that suggested by heinbloed but his method will depend on being able to turn the boiler all the way to zero (which I think it can't - just a min value)

esox28 wrote: »

btw: you wont need the duo piping when installing inside the house this piping runs @ bout €45/mtr, try and keep costs to a min as this set up wont generate huge amounts of heat when you need it.

I didn't realize it was that expensive. So it's two separate runs of qual-pex with €1 per length lagging.

esox28

I'll think between this method and that suggested by heinbloed but his method will depend on being able to turn the boiler all the way to zero (which I think it can't - just a min value

yea I know wot ya mean, but if you include the second pump on the store you wont need to turn the boiler's stat down, if ya leave the store working off the cylinder stat and room stat and leave them set and run boiler as you usually would.

championc

But the only problem with this would be that I couldn't use my CH in the winter to heat water in the store, if I choose to do this. This is the option I am considering. It would seem that using the return loop of the CH to heat the Store (as many people would currently heat their immersion cylinders) might be cheaper than having luke warm pre-heated winter water entering the boiler to be heated instantaneously for the Direct Hot Water. My boiler takes pre-heated water up to 28 deg C. But heating the Store up would mean that water could flow straight from the Store to the tap.

esox28

so what way is it run at the moment, taught of that earlier that your combi wont accept hot water, is the water for combi taken from the solar pre-heated store? try and detail as much as you can we'll c wot we can't come up with.

championc

my setup is exactly as depicted in the diagrams.

1. If solar water 45 deg C or more, them water gets mixed with an appropriate amount of cold water to deliver to the taps at 45 deg C (the anti scald feature)

2. If solar water is less than 28 deg C it simply goes to the combi for heating to temp over 45 and the anti scald will do the safety bit again

3. If solar water less than 45 but more than 28, an appropriate amount of cold is mixed to reduce down to 28 since my boiler spec requires input pre-heated water to be less than 28 deg C

As for my house layout, the solar store is in the attic, the solar mixing valve is under the landing floor outside the bathroom and the boiler is in the kitchen.


C

esox28

actually a kool system set up, you probably had combi and didn't want to change it when solar was installed.

off the top of my head I think you should leave out the connection from the flow and return off boiler and just use the second coil on store as a boost for the ch, what advantage would be gained from connecting boiler f/r to store coil, is the combi not capable of delivering volume needed at temp required?

possibly another way would be to install a divert er valve 3 port, basically you would be shutting off conncetion from boiler to store coil and opening up the ch connection which will have a separate pump on ch side (as I detailed b4) this will reverse the store coil but wont matter as you will have boiler separated.

championc

Combi's are a brilliant system. I really cannot understand many people's reluctance to installing them. For me, a Combi gives you 24 x 7 x 365 Hot Water - no waiting for Immersions. However, more importantly, you only heat the water you use. Even if you use your rads system to heat your water, you're still paying for it indirectly through the fuel used by the boiler to re-heat this water. Water would be cooler than if it just went straight back to the boiler after circulating through your rads, and so requires more fuel to heat up again to the intended temperature. So with a Combi, it also gives you hot water instantaneously during the summer when you won't have the heating on at all.

So where does Solar fit in with all this. Firstly, I shouldn't need to use any Gas during the Summer to heat any hot water. Secondly, during Autumn and Spring, I'll have similar days but in the times when I have little Solar heated water, I'll still be using less Gas because the water starting temperature will be higher than what it would have been if coming directly from the rising main.

So my logic was
a) to pass heat from the Solar to the Rads on days in Late Spring and Early Autumn when I previously would have used the CH for maybe 1 hour to take the chill out of the house in late evenings.

b) to pass heat from the Rads to the Solar during winter to heat the water thus bypassing the need for the Instantaneous water heating function of the Combi. This would only be worthwhile if it's cheaper to heat the water indirectly from the rads rather than heating instantaneously.

So Option a) might be a bit barmy but b) is possibly worthwhile. However, from my data which the system collected last summer (Solar Controller has SD Card), option a) would seem like a decent runner.


C