How To Install A Fireplace Damper Plate InstallationSince May 2. Currently, EPA does not regulate masonry heaters and fireplaces. However, the manufacturers are free to adhere to the emission standards of EPA voluntarily. These units are called EPA qualified and are endorsed to ensure more clear burning than the unqualified and older ones. You need to find out with your local or state air quality agency for knowing which wood burning fireplaces are endorsed for use in your locality. Factor 2 Combustion Technology. Well, you have the option to choose either catalytic or non catalytic combustion technology. While both are effective, they differ in terms of performance. In catalytic mechanism, the hazy exhaust gases go through a ceramic honeycomb coated with a catalyst. This honeycomb is placed deep within the unit where the ignition occurs to deliver a steady but long heat output. Windows 7 Key Finder Serial Number on this page. Such units feature a catalyst bypass damper being run by a lever. The catalytic substance disintegrates with time and needs to be replaced. However, its lifespan is mostly how carefully the unit is used. With proper care, the catalyst can live over two years. On the other hand, there is no catalyst in a non catalytic combustion and rather forms a good combustion environment in the firebox. This environment is formed through firebox insulation, pre heated combustion air brought in via small holes from the fireboxs upper part, and a baffle for redirecting gas flow. Non catalytic units usually generate more heat output and are more popular for the beautiful fire. Due to high temperature, a few internal parts including baffle need to be replaced frequently due to heat based deterioration. While the mainstream makers are turning toward non catalytic technology, a few popular high end units still come with catalytic combustion. In terms of efficiency, both burn up to 9. So now, it is the matter of your choice Factor 3 Heat Output. Most makers specify their heat output in BTUs or British Thermal Units BTUs per hour, which in case of most wood burning fireplaces falls in the range of 3,0. Well, you should not always consider the highest possible output, as non stop high firing can cause grave damage to the fireplace internally. Moreover, a home of an average medium size does not need more than 5,0. BTUs of non stop heating power, even in winter. In short in case of wood fireplaces or inserts, bigger is not always better. In case you go for an undersized fireplace, you will not get sufficient heat to warm up the desired amount of space. Similarly, an oversized model can lead to hazards or hassles by overheating the space quickly due to which you may have to open windows frequently or lower down the generation of heat. The latter is dangerous, as slow burning wood leads to more accumulation of creosote. At times, the specified figures can be misleading. For example, a few manufacturers reveal the BTUs after the EPA test using softwood, while others have their own tests using hardwood that usually lead a higher peak output. Similarly, non catalytic units generate a heat output of higher peak but this is not to ensure that they will generate more heat during the burn cycle of eight hours. Therefore, just keep these points in mind and do not compare the ratings, as they are not standardized. Factor 4 Heating Capacity. This factor determines how many square feet of your home will the unit heat up. This is also specified just like the heat output.