The FlueCube Chimney Cowl
Improving ventilation above wood burning stoves and heaters since 2009
The FlueCube is a new, unique in design chimney cowl that is being observed to relieve symptoms of negative pressure on solid fuel appliances worldwide. These symptoms are typically experienced in the worst winter conditions, especially in heavy inversions; atmospheric conditions that can be observed to contribute to poor combustion and visible smoke/ particulates inside and outside the living area via the exhaust/ ventilation.
In 2008/ 2009, when strict log wood heating appliance labelling laws came to Nelson and other regional councils around New Zealand and Australia, Neville D'Herville developed his stainless steel design which consists of a cubic combustion chamber, spark arrestor - flat mesh top, inverted cone and rain shield. On first trial the positive effect on the home heater operation was immediate and his 'chiminee' cap at $500+ got immediate local interest and demand. It received in addition, resistant controversy from the appliance change-out policy planners. Due to observable results it was suggested it was able to 'correct' smoke problems on 'older' uncertified appliances. It did so in real life - observably, above new emissions certified appliances included, and it did do so as a 'non-inclusion' from regulated appliance standards. The local media used a council manipulated 'insurance scare' follow up article against it even though it had already been assessed as 'safe' through experienced European industry standards and other appropriate independent tests. Without mandate, Some NZ environment officers still suggest it is the only cowl on the market that needs to be lab tested - by them, and on multiple models of their certified appliances.
Legally, the cowl is found in regards to appliance 'emissions' standards a non-inclusion. As a chimney cowl, it is unique in receiving European industry standards. People can rightly be selective on what industry standard ventilation retrofit they place above their certified, consented wood burner and flue installation to relieve down draft/ blow back symptoms. A cowl/ rain hat should not however, negatively affect the upward flow of exhaust gases from the appliance. Nothing has been advertised to consumers in regards to chimney cowl standards/ separate consents applications, and there is no apparatus known available that would be assessing the effects of atmospheric back pressure in normal winter operating conditions, from above the appliance, as an inclusion in laboratory calibrated emissions and efficiency standards.
For our UK and Europe distributor there was no issue getting the design tested and certified to BSRIA standards for its appropriate application - a solid fuel burner's exhaust/ ventilation. In New Zealand, it appeared they had no idea what they were testing. The design is patented under application in 40 countries. It is endorsed by UK and European chimney specialists and chimney sweeps, with many making strong recommendations. Here are some hyperlinks to what others are saying about down draft/ negative pressure: www.solidfuel.co.uk, www.nzhha.co.nz, and here.
So, what's the theory?
Light, warmed air travels upward inside a vertical cylinder. In winter, cold air falls heavily downward on top of it. Without adequate protection on the flue terminal/ chimney, fires can be hard to light - smoke spills outward into the living areas, and regardless of common modern appliance designs, often out the chimney too. Through the primary burn/ heating period combustion can be inconsistent and the overall operation sluggish. A flue without adequate protection cools down faster than the appliance and will cause the fuel to slowly smoulder out. The cowl promotes an overnight burn ability by protecting the flue terminal, not only from wind, rain and snow, but more simply; with pressure differential - from winter's 'cold, heavy air'.
A typical FlueCube experience by consumers is no visible smoke after lighting within 2 - 3 minutes, toward double the burn time conserving their wood fuel, and an odourless - overall cleaner, self sufficient wood heating system - more reliable, and in winter conditions. A well designed appliance with a FlueCube ventilating it can lower common smoky problems - affordably, and without the need for electric fans or filters.
We must do what we can to reduce wood smoke emissions and residential smog. Is it the method at fault or is it only the bi-product? Why is there a National Standard certifying wood burners when the very authorities regulating it are not allowing them in certain council zoned airsheds? Many use it to manipulate a 'greened' fuel/ electric source switch. So what is wrong with the standards? Social marketing/ advertising chooses the 'method' to blame for air quality issues, not it's possible bi-product that technologies can solve. The standards, regulations and their justifications are not keeping up with technological improvements and consumers need to consider health impacts from not having sensible, legal access to safe, affordable log wood heating as a viable 'clean energy' source; sustainable and resilient. Homes need their health protected in power cuts and fuel shortages. These can impact on our ability to cook, warm ourselves and operate hygienically. In my view, self sufficient wood options should be improved using only appropriate science and engineering, the choice mustn't be phased out/ taken away from us politically.
Please Note: Although the FlueCube is easy to install, we do recommend using/ consulting with a registered log burner and flue installer. Flue standards are written into the building code. Installation of the FlueCube should not interfere with those existing flue standards. BRANZ: Flue Installations in Enclosures, BRANZ: Installing Solid Fuel Heaters.
We are available throughout the installation process and welcome your feedback and enquiries to get the most out of your winter wood heating experience. Happy heating.
WHERE ARE COMMONLY EXPERIENCED VENTILATION/ EXHAUST FACTORS
IN APPLIANCE EMISSIONS RESEARCH, STANDARDS/ LOCAL WOOD HEATER RESTRICTIONS?