There is nothing prettier than an open wood fire but if
you’re trying to be frugal it gives little comfort to know that 80 percent of
the heat it produces disappears up the chimney. A wood burning stove is much
more efficient and effective. For a start it acts more like a radiator than a
fire. The heavy iron casing throws heat into the room and the huge chimney is
reduced to a single small flue. The rest of the chimney can be sealed with
insulation to keep heat in the building.
There was a wood burner here when we bought this house - a ‘Vermont’ cast iron job putting out 8 Kwts of
heat and it was enough to keep the whole
house cosy even during a hard winter.
But as a heater for a second home, a holiday home, it had a
few drawbacks. Firstly, it took about a day and a half to reheat the fabric of
the house, so if you came here for a long weekend, say arriving Friday
afternoon, the house wouldn't feel really warm until Saturday night. Secondly,
because the chimney wasn't used between visits and it hadn't been lined or
capped, rain water came in.
One February night we arrived here, lit the stove and choked
on the smoke which filled the room. Investigations the next morning turned up a
dead pigeon and an owl in the flue. They had obviously fallen in there and died
a horrible cold death. Soon after we had a ‘chapeau’ fitted to the top of the
chimney to prevent further useless deaths – and to help keep out the rain.
But, by then the iron stove had rusted due to the rain and
lack of use. Bits were beginning to fall off. A new stove was called for and it
was one of the first improvements we made when we moved here permanently but if
you’re thinking of getting a wood burner it is important that you do some
thorough research into your needs and circumstances.
In France stoves are described according to the heat they
put out – the measurement is in Kilowatts.
Now a stove is most efficient when she is burning good wood and when she
is stacked reasonable well. It’s difficult to have a small fire in a stove so
you need one that produces enough heat when burning efficiently – but not too
much – otherwise you’ll be opening doors or running half empty which is not
efficient.
To calculate what size stove
you need, begin by obtaining the ‘volume’ of space you want to heat. Measure
the width, length and height of your room and then multiply the three
measurements together, i.e. width 8m x length 4m x height 2.8m = 89.6 cubic
metres.
Now, if your house were a new
build and fitted with very good insulation, you would divide this figure by
25. For a room with average to good insulation you would divide the volume by
15. If the insulation were poor or non existent, then the division of the room’s volume would be by
10. If you are unsure use 15 to get an
idea of the Killowatts you need.
Ok so that is the size of
space you want to heat but if you've got an open staircase in your living room,
heat will rise up it. This may be a good or bad thing, you may want the hot air
to rise through the upstairs of the house – or you may prefer to insulate your
room and use other solutions upstairs. Either way, just remember that heat
rises and bear that in mind when you make your calculations.
Another thing to know is that old stone houses like this one
prefer a fairly constant level of heat and humidity so you need a stove that
will bring the house up to your preferred temperature steadily and then
maintain that temperature at an efficient burn.
Finally
the size, type and quality of your wood matters. Generally any dry hardwood will do but Oak is
one of the most popular because it is very dense, it burns slow and hot, and it
is easy to split. Birch also burns well but it burns fast. Poplar is popular as
is Ash and Elm.
Softwoods
are not so good because they contain a significant amount of resin which can build
up in the flue and, over time, you risk an uncontrolled blaze in the chimney or
flue. The drier and more mature the wood the better. An easy test is to bang
two pieces together; a dry mature log will have a musical note. In this
part of France wood is sold by the Cord a cubic measure of neatly stacked logs
3M x Im x Im. Three Steres make a Cord.
I use about a Cord and a half each year at a cost of about 360E per year.
Generally,
in this part of France wood is sold as 30cm or 50cm logs. 30cm logs are more
expensive because there is more wastage in sawdust. Now, ‘here is the rub’ as
Shakespeare would say, our new log burner is an ‘Invictor’ which takes logs of
45cms! Bit of a pain really, either we pay more for smaller logs or I have to
re-cut every log in my store!
If you have the space, you can save money by sourcing your
own wood, cutting, storing and seasoning it yourself before it will be required, or by purchasing cut logs ‘green’, and seasoning as above but you need to get at
least a year ahead (two years is better still) – purchasing or cutting, stacking
and protecting now for 2015 or later.
Well, in France they say a log warms you up twice – once
when you cut it and again later when you burn it, - but once you find a good
woodman treat him as a family treasure.
If you are thinking of buying a log burning stove, there is a great deal to think about. I used this book and found it a great help in making a good choice
The Log Book: Getting the Best From Your Wood-Burning Stove, 2nd Edition (USA Readers)
the log book (UK Readers)
David