March, 2007
The age of fire has not sputtered out in New Zealand. But new rules and regulations mean you have to plan carefully to realize your wood-burning dreams. Kiwi homes have been under pressure to quit smoking since 1 September 2005, when new national design standards for wood burners came into force. As part of the Government’s National Environmental Standards for Air Quality, the latest rules aim to reduce the pollution being pumped out by our domestic fires.
Today’s wood burner has to be a lean, clean, heating machine. All wood burners installed after that date, on properties less than two hectares, must chuck out less than 1.5 grams of particles for each kilogram of dry wood burnt, or one gram if you are in the Canterbury region. They must also have a thermal efficiency of at least 65 per cent. This means more than two thirds of their fuel must be completely converted into heat.
Local council’s are all fired up about pollution. They will require you to obtain consent to install a burner, and it’s important to check with them if they have other criteria which need to be met. In urban Christchurch, for example, you will only get consent for a wood burner if the place had solid fuel heating before.
What’s the fuss? Every marshmallow toasting opportunity generates carbon dioxide and potentially toxic carbon monoxide – two of the gases on the climate change Most Wanted list. An inefficient fire can also contaminate your home and its surroundings with fine particles of soot, hydrocarbons, formaldehyde and other nasties. These risk human health if inhaled over long periods and could pose a cancer risk.
The rules are a breath of fresh air for Christchurch. About 80 per cent of winter air pollution there comes from open fires and wood or coal burners. On some still days the result is skies in a rather retching shade of smog brown. Nelson and Otago have also found themselves under an artificial cloud.
Are the days of the open fire numbered? Old fashioned open fires throw 80-85 per cent of their heat straight out passed Santa’s welcome mat. They are much less efficient and more polluting than enclosed burners and can leave a draft when unlit. Not to mention the possibility of a flying spark burning your des res to the ground while you are rummaging around in another room, looking for some warmer clothes to put on.
Still want a fire with no door? Open fires are not covered by the national standards. But their installation and use, as well as the installation and use of all solid wood burners on larger property, is subject to the regional plan for the area in which you live. Auckland has set an emission limit of less than 4g/kg for those falling under its jurisdiction. Canterbury’s regional plan has already stopped the use of open fires in its Clean Air Zone 1 around central Christchurch, and will also ban the use of wood burners there which are more than 15 years old in 2008.
You can keep the home fires burning. The Ministry of Environment keeps an online list of wood burner models which meet the national standards (see below). It doesn’t cover everything, and the ministry doesn’t guarantee burners from the list will always pass all regulations if tested. But it is in the process of being independently verified and it’s the safest place to start shopping. Fire dealers too, should be aware of the regulations and will offer information and advice. The approved list currently includes 13 manufacturers and more than 70 models, which should be enough to suit anything from a West Coast batch to a Clevedon mansion.
Fire can be cool. Metro’s Eco Tiny Trad is the most efficient on the list, with just 0.72g/kg emissions and 78 per cent of its fuel converted into 9.5kW of toasty glow. It boasts the smallest floor protector of any New Zealand-made wood fire, and is ideally suited for heating areas up to 100 square metres. It can be bought for about $1,200 and installed for under $2,500, so it should keep a small room nice and cozy without burning a hole in your pocket. The imposing Firenzo’s Lady Kitchener EF will pump out about 23kW when fully loaded, enough to warm 200 square meters, and lighten you bank account by about $4,000 including installation.
You get out what you put in. The Ministry’s list states the authorized fuel as dry wood. It recommends only seasoned unpainted and untreated wood with a moisture content of less than 25 per cent. Reading this now, you should have a full stock of firewood in store from the summer, when prices are cheaper. This also allows enough time for it to be loosely stacked under cover to dry out properly. Chop it up yourself if you want it to warm you twice.