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For certification of custom fireplaces, every province, state, and sometimes city or county will have their own way of approving custom installations, with varying degrees of emphasis on the different aspects. In our experience, the best way to deal with this process is to have a complete set of schematics, shop drawings and specifications prepared for the installing contractor or mechanical consultant to submit to the authorities for discussion. This can be both a potential protocol for testing and a pre-approval in principle.
In designing a custom fireplace, there are three main areas that have to be addressed for the purposes of approval: The fireplace enclosure and clearances, the burner and valve control train, and the vent system. Ultimately the fireplace must work as a whole, but the issues regarding these three elements are often treated separately.
The firebox enclosure can be the key to a fireplace being approved. While the burner systems are easily site tested and the venting is generally composed of off-the-shelf components, a custom fabricated steel firebox has no rating for clearances to combustibles or surface heat. Vancouver Gas Fireplaces has developed a method for fabricating custom fireboxes in virtually endless sizes and configurations using two fully welded steel skins with a 2100-degree heat barrier blanket and an air space in between the skins. This fabrication method has been independently tested and approved for a number of installations.
Some jurisdictions, if shown the specifications and shop drawings for the firebox, will allow approval based upon site testing. Others will allow the installation of an untested enclosure if installed into a secondary masonry enclosure. Many jurisdictions however will not allow the installation of an untested firebox without testing by an approved agency to an agreed upon standard, which can add thousands of dollars to the project and an increased time line.
An alternate solution to having a custom fabricated firebox is to construct a masonry firebox to the size desired and install a custom gas burner into it. The firebox can be built with a smoke chamber tapering up into a masonry flue or approved metal chimney. Alternately, a fabricated vent collection hood can be designed to taper up into the venting. Most jurisdictions will have little trouble in approving these types of gas installations.
There are several types of burners used in custom installations: Basic log sets, sand pan burners (with logs or any non combustible objects on them), crushed glass burners, manifold burners with holes drilled into a steel plate, simple pipe burners with a row of gas jets, and more. The keys to the approval of these burners are the valves, ignition components, and control devices. The various attached pieces are almost always comprised of components with approved listings. If pre-submitted with a schematic, there is usually little problem obtaining an approval. The only other issue that can come up but seldom does is whether or not the burner burns cleanly. This is usually dealt with in the setup.
Venting the fireplace is the third area in designing and getting a custom fireplace approved. Custom fireplaces, if side wall vented, are almost always power vented, as it is very difficult to get approval for a custom passive direct vent without complete shop testing. We also like to use powered draft inducers on most vertical installations because invariably we are trying to vent a firebox with a large volume of space, with a reduced vent size determined by site conditions. As with the burners, most of the components that go into a vent system, such as the venting, inline power vents, draft inducers, and pressure switches, have their own off-the-shelf approved ratings. Often the collection hood or vent connector will be custom designed and fabricated.
Custom vent system pieces are seldom an issue with getting approval if an adequate gauge of material is allowed for clearance to combustibles. If planning for a custom fireplace, make sure each of the three main areas are adequately thought through and planned. If you present approval authorities with a complete set of specifications covering all aspects, you'll find that any approval issues will be greatly minimized.
Robert Koby owns Vancouver Gas Fireplaces.
Vancouver Gas Fireplaces is North America's leading wholesaler and innovator of custom fireplace design and implementation. VGF provides the most comprehensive fireplace website to architects, builders, designers and renovators.
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