Posts Tagged ‘Wood-Fired Stoves’

Shopping List – latest update

Steadily firming up the shopping list for our new house – here’s the latest list, with links. 

Kitchen

Dining Room

  • Expandable table

Playroom

  • Instant-heat to stand in front of (Gas?)

Lounge

  • Wood-fired stove
  • Central Pendant light in diffusing shade – 12v CFL?
  • Two Standard/Reading Lamps – 12v CFL?

Garden

  • Kitchen Scraps Compost: Black Soldier Fly Composter / Worm Farm 
  • Firewood store, and at least 12m³ of wood
  • Greenhouse with Aquaponics system

Heating & Hot Water

Power & Light

Water

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Using a Wood-Burning Stove in a Smoke-Control Area

esse100seThis is something we need to work out – our new house will be in a smoke control area. To check whether you’re in a smoke control area look up your local authority here. If you are then the only wood or multi-fuel burning stoves you can fit are listed on the exempt appliances list. It also explains what types of fuel you’re allowed to burn in them.

There is a good collection of the usual suspects – Clearview models, the Dunsley Yorkshire range, several Rayburns and Morsos. And some I haven’t looked at before – Dovre, Hwam, some Stovax models, and Westfire. Stoves Online have a great list of their clean-burning stoves, with links to piccies and details

In a surprise, Esse do not have any models on the list, but a quick check of their site shows that they have just launched (9th Feb) a new model that is OK in smoke-free zones. It’s the compact 100SE model – as shown in the photo!

Wood-Fired Ranges in a PassivHaus

In my PassivHaus Renovation post I said that:

Any non-solar water heating to be Gas Condensing boiler or CHP – wood fired stoves are not permitted (this conflicts with my peak-oil resilience planning)

In return I got a comment posted by Andy Simmonds at the AECB stating:

The AECB standards do not proscribe wood stoves, nor does the german version of the PassivHaus standard.

I’ve been back to the AECB standards and here are the sections of the Proscriptive Standard that deal with heating & cooking:

Space heating (Silver Standard):

Normally radiators or underfloor pipes. Fed from SEDBUK A-rated mains gas condensing boiler, CHP or, outside the gas supply area, SEDBUK A-rated LPG or oil condensing boiler, earth-source heat pump (seasonal COP ≥3.0) or cleanburning biomass boiler; i.e, one using liquid or gaseous fuels. Wood pellet boilers are permitted outside the gas supply area but are not encouraged due to the exhaust emissions. Blocks of flats or maisonettes to have a central boiler and/or CHP plant or heat mains connection; i.e. heat distribution within the block rather than individual boilers or electric heating.

Space heating (Gold Standard):

Normally hot water coil(s) in ventilation ductwork. Circulating pump consumption ≤0.1 W per m2 floor area or pro rata; e.g., Grundfos Alpha Pro or equiv. Heat sources as for Silver.

Cooking (Gold Standard):

Hobs gas, LPG, electric induction or clean-burning biomass – liquids or gases only. Ovens gas, LPG or electric A-rated. Electric min. A+ or A++

I don’t see anything in there which suggests a wood-burner would be permitted? I’ll have a chat to Andy and see if he can clarify things for me!

How much firewood should you store?

Good Size Log Store

Good Size Log Store

Huge numbers of people are putting in Wood Burning Stoves, Boilers and Ranges at the moment. They’re doing this for a number of reasons: to beat rising gas and electricity prices, to reduce their carbon footprint,  or to improve the resilience of their heating system in the face of peak-oil based supply issues.  The first challenge appears to be actually getting hold of a stove – apparently Dunsley have a 6-month backlog on orders for some of their stoves, And Stovax reported a 50% increas in orders in the last quarter of 2008. Once you have your stove though, how resilient is it likely to be? Unless you have your own woodland you are dependant on a supplier – so will there be enough wood for everyone who is currently putting in a stove or range?

The Guardian recently discussed the problems there are with firewood supply, and there are some of the facts:

  • Current UK consumption is about 1,180,000 tonnes a year.  Only 1m of those are produced in the UK, so we’re currently importing 15% of our firewood needs.
  • However, if you’re not fussy about what you burn, then there are 2.5m tonnes of burnable wood going to landfill every year – so if you see a skip full of random timber or broken pallets take it home and burn it – you’ll be helping the UK become firewood-independant.
  • Demand is increasing at around 25-30% a year, and resulting shortages resulted in price increases of up to 30% at the end of 2008.
  • The increase in demand is particularly resulting in an increasing supply of green, un-seasoned logs that will need to be stored for at least a year before being burnt.
  • There are wide price variations across the UK firewood is most expensive in the North and West, and cheapest in the South East.
  • The Government is working to bring another 2m tonnes of firewood to market by 2020. They say this will be enough to heat 250,000 homes (an average consumption of 8 tonnes/yr/house).

With the current supply chain under significant stress, the easiest way to ensure that your wood-fired stove or boiler continues to provide heat is to make sure that you have stored enough wood yourself. The general guidance is that wood should be stored for a year to reduce its moisture content from the 70-50% it is when felled down to an ideal <25% for burning. If you haven’t been through a full season with your wood-burner yet the general guidance is that an average house will consume 8 tonnes a year – around 12 m³, depending on your level of insulation, how hot you keep the house, whether it’s also heating your hot water etc. So – how much wood have you got stored? Two months supply? Less?

If your wood-burning stove is essential to your heating/cooking/hot water then you need to take wood storage seriously. Build a wood store – a shelter with a roof (clear if possible), open sides, and use pallets for the base and to divide sections to maximise airflow. Preferably split it into at least two sections so that you can have one section “seasoning” (drying) and one section that you are burning. Store the wood end-on to the airflow after chopping it to the right size for your stove. Make the stack as tall, long and thin as possible to maximise airflow.

Do that, and your wood-burning range can provide a really resilient solution to your heating, hot water and cooking needs.

Resources

Bin your Aga – buy a Rayburn

 

An Esse, not an Aga

An Esse, not an Aga

George Monbiot in the Guardian is launching a campaign against the Aga. He reasons that they use a ridiculous amount of oil, and generate an obscene level of CO2. I have to say that I’m with him on this. You won’t find much about Agas on GentleDescent because once I’d done the basic research and found that you couldn’t get a multi-fuel version I realised they weren’t going to meet my post-peak-oil needs. The decision was helped by articles like this one in The Times about people ditching their Agas

 

If you’ve heard about peak oil at all then surely putting in an oil-fired Aga is profoundly stupid. It’s OIL-FIRED. So when oil runs short or is out of your price range then what are you left with?  A great useless lump of cast iron, and no heating or cooking options – not very resilient! If you have to buy an Aga then at least get a Gas or Electric version, but realise that you’re doing it as a lifestyle choice, it is not a resilient long-term option.

So what should you get? I’m still working that out! The couple in the Times article went for a wood-fired Esse with a back boiler.  Ive looked at some really beautiful wood fired stoves, and the Rayburn, paired with a Solar Thermal system, but I’ve yet to come to a conclusion.

But what should you do if you do have an oil-fired Aga already? Apparently their re-sale valus is terrible, so I guess if you were feeling optimistic you could convert it to Gas, which may last a little longer, and be a little more environmentally friendly. Twyford do official Aga Gas Conversions. Otherwise? Send it for recycling. And buy a Rayburn (probably).

A Passivhaus (Passive House) renovation?

passivhaus_thermogram_gedaemmt_ungedaemmt

The picture on the left is a thermograph – showing the difference in lost heat between a conventional house (on the left) and a house built to PassivHaus standards (on the right). Which house would you rather be living in when Russia cuts gas supplies

The PassivHaus standard, as interpreted for the UK by the AECB, should result in an 80% reduction in a house’s energy consumption. PassivHaus design concentrates on three areas: improving the air-tightness of the house, reducing heat bridges, and, to a lesser extent, considering heat gain from the sun.

In essence, a typical passivhaus is air-tight & super-insulated, with mechanical ventilation with heat recovery (referred to as MVHR) to solve the issue of internal air quality. I had always believed that a PassivHaus needed no extra heating, but apparently that’s not entirely true. While they’ll generally have no radiators or underfloor heating, they often do have a small heating element within the ventilation system. In general they require about 30cm of insulation, and windows that are triple glazed.

Here are some of the key points of interest to me from the AECB version of the standard:

  • Use daylight to displace use of electric light
  • Solar hot water system required to deliver at least 50% of hot water
  • Walls, Floors, and Roof to all have U values of <= 0.15W/m2K
  • Doors (uninstalled) should have a U value of <= 0.6 W/m2K
  • Windows (uninstalled) should have a U value of <= 0.8 W/m2K, with a solar energy transmittance (inc frames) of >= 35% and a visible light transmittance (inc frames) >= 50%
  • Rooflights (uninstalled) should have a U value of <= 1.0 W/m2K
  • All habitable areas to have a glazing area (excl frames) >= 14% floor area
  • Typically space is heated with hot water coils within the MVHR ducts
  • MVHR should recover at least 75% of heat, with a fan using <=1.44W per l/s
  • Any non-solar water heating to be Gas Condensing boiler or CHP – wood fired stoves are not permitted (this conflicts with my peak-oil resilience planning)
  • Insulation on water tanks to be at least 100mm PU foam, all pipes and valves to be insulated with at least 40mm mineral fibre, and all cold pipes to have a vapour barrier
  • Lighting to be >= 50lm/W
  • Use the most efficient appliances – A/A+ minimum. TV to be LCD.
  • Use a heavy-duty membrane to air-proof the house.

In conclusion, this is a great list of targets which I may I don’t think I’d go for PassivHaus certification, even though I like the overall aims – my Peak-Oil resilience planning needs things that are proscribed by the standard – like a wood-fired stove!

 PassivHaus Resources

Beautiful wood-fired stoves, ovens and ranges

A recent thread over at powerswitch unearthed a whole range of really beautiful – and practical – woodburning stoves. Here are some of the pictures, click on them to get more details.

Cucinotta Forno

Cucinotta Forno

Rosetta Maiolica

Rosetta Maiolica

Clearview Pioneer

Clearview Pioneer

 

 

 

 

 

While I love the look of the Cucinotta Forno, I can’t see it being practical to just have a wood-fired oven as a kitchen range. The Rosetta (and their larger Rosa) are still gorgeous, and seem more practical for a wood-burning kitchen range. The odd one out here is the Clearview Pioneer Oven – it could easily fit in a living room rather than the kitchen, but has a small oven – perfect for casseroles and baked potatoes – and a hotplate for a kettle. Might be a great choice as an introduction to wood-burning and an emergency cooking source. None of these have boilers though, so wouldn’t be ideal for our sole heating source.

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