sagraiasolar's activity

I don't have experience of this kit specifically but I'd doubt if it would be worth your while spending too much trying it because: 1/. The tubes are small and trying to remove heat with air as a medium so you are probably looking at extracting about 0.5kW. I say this because with a much bigger back boiler full of water on my Clearview 650 stove I am only getting something like 2kW. 2/. You should consider that if you remove heat from a fire that the efficiency goes DOWN because the lower temperature may not enable some of the heavier creosote type combustibles to burn.  What you could do though, for a lot less, is to get some shiney stainless steel walls made for the fire to reflect heat into the fire and back at you to give better thermal efficiency and extracted heat via radiation.  I once transformed an industial gas oven just by lining the floor with kitchen foil.  If you really want to do the grate thing then why not just make one out of gas barrel fittings - sealed or welded to make sure you don't gas yourself - and give it a trial blow through with a hair dryer on cold. A fun project for about €30 - please report back. Now you have liberated the €1,000 you can buy lots more wood.  Finally about efficiency claims: as open fires can become negatively efficient then ANY heat extracted can produce any amount of efficiency claims you care to print.

I'd comment on the Jotul plug Fillide.  When chosing a stove there is more to it than finding a good brand. If it is to be stand alone without connection to water it will usually need to be physically quite small or it will be too hot for all but the biggest rooms. Connecting to water allows for a 'nice' big stove as some heat is removed to produce domestic hot water and heat for passing round the heating system.  Many of the less expensive stoves in cast iron have their back boilers cast into the stove - when they crack you have to buy and fit another 'less expensive' stove. I won't plug the ones with a stainless steel clip in back boiler because I use them almost exclusively in my designs but the boiler mod is the thing to look out for. Also I like to keep the power down to about 14kW with only half that going to water. After that there is too much log lugging. Nothing at all against Jotuls - just make sure they are fit for the purpose.

... assuming the radiators are already there and you are contemplating a retrofit ... you can swap one or two radiators for fan coil units and then use them for aircon in the summer. If you get hayfever you alleviate it by having plasma filtered fan coils

I agonised over all this for 2 years before a solution appeared. The techies would come round with sensors to point at masts etc and I never knew that they were ignoring rivals masts which were showing loud and clear. We nearly fell for a repeater mast at €2,000 + our own costs when some local guys came round, found their mast and fitted it all up in 30 mins and then left - €100 for fitting. A local friend was stiffed for over €2,000 by our local sat guys and now uses the same firm as me to get a proper service.  The whole side of the valley opposite me gets a relayed signal from my house ... i.e. don't assume you have to see the mast to get the service.  They extend coverage all the time so keep at it.. and good luck. P.S. the phone for €3 a month works really well.

yes qui gia is right - it doesn't dry out easily until cut and split. If you do this before the summer and leave it unstacked to bake in the sun then you can just get away with a one year cycle. My test log lost 20% in the first 6 weeks of sun baking and then settled down.  Strangely, hard woods don't seem to get wet again so easily... I did some tests with a moisture meter on some Ramin and even total immersion did not make much difference - the point is that a shower of rain doesn't matter much. As soon as it drops below freezing and moisture in the air gets frozen out then the wood continues to dry so, weirdly, winter is good for more drying out.

"Do your calculations produce "acceptable" warmth in every room in the house over the year?  What temp would that be by the way??" Annec, The answer is that the figures are for properly heated houses with 21c all through. Your 'pass the parcel' approach is more realistic and as long as the system is properly zoned - so you can turn parts off - the real world situation is much better. The trick is to replace all standard thermostats with programmable ones so that precise timing is allowed... e.g. BTcino L/N/NT 4450   For a real example my box on a hill is 300mq - outside measurements - and €1,200 of wood does the winter with most of the ground floor at 21c +  ... helped with under-floor heating.  Being a 2 layer house the bedroom rads seldom need much more than a brief burst in the evening.  Solar panels cover the summer and the PV car port covers all the bills. For a while it was possible to build ZERO COST systems but PV is pretty much off the menu for a while unless you snuck in really quickly.

... OK lets see if I can get to grips with this. First look at my 'Stacks of power' demand graph exactly shows that 34kW will cope with -5c so that's spot on.  I'm going to assume that a 400mq is 1.6 times bigger than a regular house so the power demand over the season will be 1.6 x 25,000 kW.hrs = 40,000 kW.hrs... plug that into the seasonal Power balance model - first with a GSHP on a COP of 3 and the lower tariff (saving just over €1,000) the energy bill looks like €2,942 a year.     Going over to wood only - and here we get less precise as it cd be wet etc: it would take say 100q to produce 25,000 kW.hrs so 160 for the 40,000 kW.hrs which is €1,920 at best.  However who wants to stack so much wood? A mixed system with 100q of wood would cost €2,636 - only one heat pump needed though.  Interesting result really as it shows that once the upfront costs of the lower tariff are absorbed the cost of running a big heat pump is close to wood. N.B. please excuse the  absurdly precise figures - just reading off the model.

... blimey - calm down folks   lets talk turkey for a minute.  The rates here are €12 and some folks get away with €10.  It is REALLY important to know how dry the wood is for a couple of reasons. 1/. If it's wet you will be buying a lot of water  and 2/. ... the heat output can be as much as 50% less. Wood furnaces in particular are very fussy about dryness. For 500mq I'd say 100 quintale is too little and you'll run out - more like 200 would be the mark... if there is some left over then that's your dry start for next year.  Having said that, although I'm a wood heating enthusiast, I tend to design systems which only use about 120 Quintale on the grounds that any more becomes too much of a chore. 2 wheel barrows a day is enough and so is ONE stove too. After that - sorry to bang the drum again - the next best thing down the energy chain is a heat pump. All this wood should have been split and drying from last May so take care with the wetness.

This is a really low powered device which just makes hot water and rather slowly. ... If you are going to get a heat pump it needs to be properly sized for your whole house requirements.. The system I describe is not the same at all which is simply a large tank fed by heat sources such as stoves, solar, heat pump etc... the hot water, rads, floors etc all get fed by the tank and or the heat pump.    Mixing wood with a heat pump is technically quite hard to get right but it is worth it, I think, because wood is cheap and smaller heat pumps can run on the power of an electric kettle so don't always need any electrical changes.... also domestic PV arrays might be producing 2kW on a winters day so the heat pump runs free and produces around 6kW and if that isn't an engineering miracle I don't know what is.  www.heatweb.com is a good source for info. 

Qui gia - Andy has kindly said it all for me.  Chains make a huge difference in really extreme conditions and Landys can do extreme pretty well - now remembering scraping down a steep gully so steep I had my feet on the windscreen. Yes my Landy is LHD (and has never been scraped down a gully).... did I mention that it comes with a trailer for fetching logs and stuff?