Heating System - Solar Panels and Solid Fuel?

HoofRocks

Hi All

Just looking for some advice. We are currently trying to decide on a heating system for our 1600 sq ft bungalow.

Would we have sufficent water and home heating from solar panels and a solid fuel stove with a back boiler for rads or would we also need a back up like oil.


We'd rather stay away from oil so would these two systems be enough or is there another alternative. Were not putting in under floor heating.


Thanks for the help.

Outkast_IRE

Yes its entirely possible to have a house completely catered for by solar panels and a solid fuel boiler.

if you want to do it correctly your going to get an architect to do a dwelling energy assessment procedure (deap) im open to correction here guys.

And then you should be able to appropriately size your solar panels and solid fuel back boiler.

If your doing it this way i would personally be looking at a large buffer/accumulator tank. In houses with a oil/gas backup system an average size i see going in is 1000ltrs, if you dont want any backup and wnat to use the buffer for all your heating i would be inclined to size a larger tank again , but this all depends on how much energy your home needs to stay heated.
Get the architect to do the calculations and then work from there.

if your doing it this way , i would instinctively say i would hope that you have a large south facing roof area, and i would personally be looking at installing a high performance tube system for the solar.

As a final note , i would only reccomend using a undefloor heating system from the buffer , and i would hope your aiming for an A rated home. The less heat energy your house loses the less energy you need to input to heat it.

kieranhr

To expand on Outkast's point a bit, the real problem with installing only a solid fuel system for your space heating is the lack of control. You'll get plenty of heat out of it if it's sized properly, but you won't be able to turn off a solid fuel boiler when it gets too warm, and you won't be able to set it to come on automatically. You won't be able to use Thermostatic Radiator Valves either, because you can't shut down a solid fuel boiler automatically, so you have to leave the radiators open to give the hot water somewhere to go.

All of these problems can be solved by providing a buffer tank, provided you get your plumber on board early and he sizes it properly. Then you can fire up the solid fuel stove, heat up the buffer tank and draw hot water off this as required.

quentingargan

I've been living on a solid fuel stove and solar panels for the last 12 years. We mainly burn sitka / ash from our own woods.

If the house is well enough insulated, there isn't much point in spending more money on your heating system than you absolutely need.

We don't have a very large buffer - just a 300L solar cylinder. The surplus goes to radiators. If you are burning timber, then while you need enough heat dump capability in case of a power cut, you don't really have a runaway situation. The fire heats the radiators, and when the house is warm enough, you stop putting logs in.

It isn't for everyone. From the moment you light the fire, until you get a rise in temperature, it takes longer than with oil fired central heating, but if you are home all the time and have the time and energy to live with this system, its cheap to run - just a bit of fuel for the chainsaw.:)

HoofRocks

thanks for all the posts guys very helpful

kieranhr

quentingargan wrote: »

We don't have a very large buffer - just a 300L solar cylinder. The surplus goes to radiators. If you are burning timber, then while you need enough heat dump capability in case of a power cut, you don't really have a runaway situation. The fire heats the radiators, and when the house is warm enough, you stop putting logs in.

A question for you Quentin - do you draw hot water for space heating off your buffer tank, or is it just for domestic hot water?

quentingargan

kieranhr wrote: »

A question for you Quentin - do you draw hot water for space heating off your buffer tank, or is it just for domestic hot water?

Just hot water. IMHO, if you have a reasonably well insulated house with passive solar heating of some sort, there are no times when the solar panel has a useful role in space heating. Its a bit of a mismatch. But maybe with large buffers my views on that could be changed this summer... Q

Outkast_IRE

quentingargan wrote: »

Just hot water. IMHO, if you have a reasonably well insulated house with passive solar heating of some sort, there are no times when the solar panel has a useful role in space heating. Its a bit of a mismatch. But maybe with large buffers my views on that could be changed this summer... Q

I do think a large buffer is a great " peace of mind " component of such a system though for a lot of people.

I think its great the system your using, and its a proven system that works.
But as you say , you need someone around the house to keep her lit when needed etc.

If nobody is around the house during the day, i would sometimes look into the possibility of using a wood gasifiaction boiler , linked to the buffer , with the buffer being topped up/helped by an appropriately sized solar array.

The advantage for a lot of familes being the wood gasifaction may just need to be stocked up once in the morning.

quentingargan

Old Proverb: He who cuts his firewood gets warmed twice.

PeteHeat

Hi,

There is a question on another thread which I suggest you take great heed of, Here second last post.

I have had customers look at me as if I had two heads when I tell them the one side effect of stoves with big boilers is bringing in the fuel needed to get the heat they need, especially as I am supposed to be encouraging them to buy one, take a look at the firebox in stoves with 20 > 30Kw output, honestly you may need a wheel barrow to keep the fuel coming to them.

I suggest if you have a heat requirement above 12 > 14Kw fit a boiler and buffer tank in a boiler house which can be attached to the house but with direct access from outside the house preferably near where you intend storing your fuel.

You can still use a stove with a boiler feeding into the buffer tank and have your solar system heating the buffer as well although the most successful system I know has the solar heating the cylinder first then diverting to the buffer, that way there is no heat dumped just stored for later use.

Don't forget to allow for heat losses and restrictions to the heat requirement figures your Architect / adviser gives you, there are a lot of people wondering why their small boiler was not providing all the heat they needed during our cold winters.

If you are installing heat recovery / mechanical ventilation it is very important that you tell your supplier (maybe even give it to them in writing) that you intend using a solid fuel appliance (stove) in the room because you will need to have a sufficient supply of fresh air for efficient combustion (for your stove to work properly).

I hope the above is of some help to you,

.