Hello all, this is my first post on the forum but I’ve been using the forum as a resource for years so I’d like to thank everyone for contributing – both questions and answers.
On this occasion I’m hoping for some advice on my particular situation and plans.
I’ll try to give quite a full background so thank you in advance for having the patience to read through.
We live in a three bed bungalow on the Isle of Skye, recently moved in (October) and currently have oil fired heating and an electric cooker. We hope to replace a lot of this system with wood fuelled options. We have had wood stoves before, as our sole heating on a narrowboat and as supplementary heating with gas central heating.
There is a redundant fireplace in the living room with a capped chimney and we have 9 radiators in the central heating system including two tiny ones.
Our demand on domestic hot water seems very low, our shower is electric and we usually wash our hands with cold water (the hot takes too long to come through anyway), aside from the occasional bath we just use a bowlful for the washing up in an evening.
I am thinking of putting a wood stove in the living room and a rayburn in the Kitchen for cooking, DHW and central heating. One of the features we’d like to have is to be able to have the central heating on for an hour or so in the mornings so we wake up to a comfortable house and to this end I think a thermal store should suit our needs.
I am not knowledgeable about plumbing and keep getting lost in the technicalities. I didn’t want the living room stove to have a back boiler as I don’t think it’s need in the system and it would just reduce the burn efficiency. I’m planning on retaining the electric cooker as a backup (very few people relying on wood for cooking seem to recommend it as a sole cooking source and we don’t have equal dedication to it in the house).
So I suppose my question is will a thermal store be likely to answer our demands for morning luxury after an evenings burn of the rayburn? Are there any gaping holes in the rest of my plan?
Thank you very much for having the patience to read through if you’ve made it this far, apologies for the scrappy details – it is difficult to know how much is relevant.
Thanks again, Adam.

Are there many trees on Skye?
Cos If paying for "imported" fuel, of necessity, oil is relatively cheap.
After insulation.
m

O.K, tape measure has been out and the area we would hope to heat in the mornings is about 106m2. We have thermostatic radiator valves so we can opt to have different 'zones' heated at different times. I'm pretty confident of the heating meeting our needs in the evenings, it is just whether a burn in the rayburn (probably a second hand fairly modern version - 355sfw for example) from about 4 in the afternoon will charge the thermal store enough to heat that 106m2 of a morning.
We are happy with the level of heat retention in the house, we could always improve of course, but it has the best insulation we have ever had and predict that the fuel consumption and supply will be manegeable. My good access to wood and having the space to season it well are significant factors in wanting to change to wood burning.

Thank you for your reply Peter. This is the bit where I get unsure about the details, I am quite open to a split system but I assume that the size of thermal store required differs to a combined system?
I did realise there would be compromises, part of my query was trying to identify these so thanks for flagging them up. It would not be a great hardship to sacrifice evening central heating to have a warm house in the morning, we mostly live in the kitchen and would have a second stove in the living room to heat that up.
The house has a suspended floor so air supply to the appliances can be provided via this without too much difficulty.
As I said, our DHW demand is very low so I can see a split system working well for us. I haven't attempted to calculate our central heating output, we have the thermostats adjusted to different settings at different times but I'll look into it a bit more and try to be more specific about the proposed system.
To clarify, when I say we want a warm house in the morning, it is more correct to say we would like a 'not cold' house in the morning.

Posted By: weebookboyOne of the features we’d like to have is to be able to have the central heating on for an hour or so in the mornings so we wake up to a comfortable house

Since you live mostly in the kitchen, why not just warm the kitchen, of a morning ?

Perhaps you could easily (and cheaply...) do this by having an infrared radiant heater, on a (mechanical) timer, so that it comes on, say half-an-an hour before you surface...

gg

Rather than try and estimate your heating load from first principles, can you just measure your daily/weekly oil and electrical usage.
Then you can plot that data against a local weather station (Skyewright has one).
Once you have that information, you then just need to compare technologies.

£50/3 months for a scavenging license don't sound like a bargain to me once you add in transport and time.
That would buy you about 800 kWh of thermal energy, via an ASHP, for space heating, which is about the same as 250 kg of dry wood will give you.

Thanks steamy, that was the point i was attempting to articulate, re "costings"
From someone who has left the log gasifier unlit all winter while burning Kero at 30p/litre
I am also running the big Morso between the kitchen and living room, fuelled purely from our own woodland, but not "cheaply" if i costed my labour and investment in the equipment so needed, and put a price on the sq footage needed to store the wood over 2 or 3 seasons.
Hence my comment that heating oil was "cheap".
No heat in the bedroom (at night) merely causes the wife to snuggle tighter, heh heh!

Posted By: weebookboyMore information. The Rayburn's output to water is advertised as 11.7kw

I'm a bit wary of that figure for its output using wood. Get some advice from more experienced users, but my guess is that in practice you'll be hard put to get anything close to that unless it's with coke. We just use ours on wood, and only as a standby for hot water during powercuts.

Thanks for all the comments and advice.
I wasn't expecting the output's of the stoves to be very accurate - I always assumed they were figures more or less plucked out of the air since there are so many variables to take into account. Likewise with the predictions for heat demand. I haven't paid a great deal of attention to it in the past, when we lived on the boat we lit the fire when cold, opened windows when hot and put up with being cold in the morning. In our last house we burned wood if I had scavenged and dried enough, used the gas if the wood wasn't seasoned and in the winter mornings - we had a high efficiency combi - boiler and used 1,129 kWh per year.
I will have to take some more time to look into how best to satisfy regs for air intake.
Insulating the floors is noted - I will also look into getting this done, if we go ahead with the rayburn I will need to build up a plinth for it so it could be a good time to sort underfloor issues.
I kind of gather the wood for for fun, or maybe that isn't quite the right term. I like playing at forrestry, I get to do it a bit at work but I got the scavenger license just so I could get out in the woods of a weekend and use my axes (infrequently) and saws (often) - I gave it all to my parents last year. I suppose I'm trying to get over the sense that my time, storage space, etc don't really register in my mind as being represented by monetery value. I am trying to make the house have as few actual utility costs as possible and to that end I want to avoid biomass, pellets, oil, or anything else I can't process myself.
Incorporating solar thermal to the store would be an option but the very limited daylight through the winter months up here leads me to believe it would contribute little when we need it most.
I will plan to have the thermal store as close to the heat source as possible.
I will investigate Peters suggestion of the rayburn cooking and DHW, and the wood burner to do space heating and TS.
Thanks again.
I'll take a little time to review the feedback.
Adam.

Posted By: weebookboyIncorporating solar thermal to the store would be an option but the very limited daylight through the winter months up here leads me to believe it would contribute little when we need it most.

It's been a while since I looked at it and I never installed it, but I think that you can get a useful amount of heat in winter from a solar thermal system if the panels are mounted almost vertically and south-facing. You will definitely need an alternative though, so perhaps the additional cost is not worth it.

Posted By: an02ewand diffidently put some solar thermal of summer HW

Solar thermal or would PV be better?

<blockquote><cite>Posted By: Peter_in_Hungary</cite>Solar thermal or would PV be better?</blockquote>

Solar thermal, its cheaper, can be self installed by competent person

Posted By: an02ewSolar thermal, its cheaper, can be self installed by competent person

Posted By: an02ewPV is dead! Long live Solar thermal!

I wish I had time to tear that apart

Posted By: Ed DaviesThe disadvantages of PV are, as DJH says, greater area and also the lack of a cheap off-the-shelf solution for heating applications.

Compared to the costs of most other heating solutions, a solar diverter and a fan heater or immersion are very competitive I think.

Posted By: Ed Davies. The disadvantages of PV are, as DJH says, greater area and also the lack of a cheap off-the-shelf solution for heating applications.

Not quite at the fan heater level but I think small air-to-air heatpumps deserve consideration as cheap off-the-shelf solutions, or partial solutions at least. A good fit with PV in shoulder months, and Skye winters are relatively mild and windy, so should be decent COP and plenty of green electricity around in winter. Also good in the event that enthusiasm for forestry/woodburning fades!