EXCALIBER
ArboristSite Guru
Cat stove are not necessarily more energy efficient. They do however burn much longer than a secondary burn stove. Their heating curve is a lot flatter so it keeps radiating heat at a lower level for a long time. The downside of Cat stove is they are huge in order to provide the long burn time and in my estimation they are sinfully bugly!
I agree with most of your points except the 2 above. The only and I mean the only useful piece of information on the EPA label is the g/hr. That's all EPA is concerned about. The BTU's & efficiencies are bogus on the label. Yet they insist we put them there.
So here is the explanation... Remember we are testing for EPA smoke emissions, not efficiencies or BTU's. When the tests are conducted the protocol calls to burn BC fir (softwood) in small QTY and cribbed. So of course if you dont put wood in the stoves your BTU ratings will be low! Since nobody burns like that most MFG conduct their own BTU tests using mixed cordwood.
All EPA labels rate every single stove MFG'd since the 80% at 63% efficiency. That's actually not tested. What EPA is saying in effect is "If this stove is EPA rated, you should expect a minimum of 63% efficiency". It's a benchmark, untested value and is meaningless. However, since EPA is a gobermint agency they force the MFG to put that figure there no matter how meaningless. With the new EPA legislation this label will hopefully be changed to reflect better info.
There are more moving parts in a Cat stove there will ever be in a non-cat. The only time you would ever need to replace the burn tubes is if you had a major overfire which made them sag. Of course by then, other stuff has warped and cracked. The ceramic blanket on top of the baffle is there to provide more insulation. Once its got dirty and matted you can throw it out and dont have to replace it. It makes little difference.
No cat stoves are not necessarily more efficient, that is on a stove by stove basis. As a blanket policy the cat is more efficient though. Actually they list the stoves with different efficiency's right from the EPA:
5. What types of EPA-certified wood stoves are available for sale?
There are three basic types of wood stoves that have received certifications under the wood heater program:
Catalytic wood stoves are equipped with a ceramic or metal honeycomb device, called a combustor or catalyst. The catalyst is coated with a noble metal such as platinum or palladium that reduces the ignition temperature of the unburned volatile organic compounds, P\particulate matter and carbon monoxide in the exhaust gases prior to their exit into the atmosphere thereby reducing particulate matter emissions. As the components of these gases burn, the temperature inside the catalyst increases to the point at which the ignition of the gases is essentially self sustaining. Wood stoves equipped with catalytic combustors are assigned a default efficiency rating of 72%.
Pellet stoves are those wood heating appliances fueled by pellets of sawdust, wood products and other biomass materials pressed into manageable shapes and sizes. These stoves have active air flow systems and unique grate design to accommodate this type of fuel. Some pellet stove models are subject to the wood stove regulations, while others are exempt due to a high air to fuel ratio. Pellet stoves are assigned a default efficiency rate of 78%.
Non catalytic wood stoves are those wood stoves that do not use catalysts but do have emission-reducing technology. Typical emissions-reducing design characteristics for an EPA certified non-catalytic wood stove include baffles and secondary air chambers. Non- catalytic wood stoves are assigned a default efficiency rate of 63%.
Now all the metal secondary tubes in all stoves I have looked at were a wear item as stated by the manufacturers. Slowly loosing efficiency just like a cat over time, eventually needing replaced. They are tiny thin walled tubes reaching repeated super high heat as needed for efficient burning in those style stoves. As anyone knows little tubes, high heat, equals metal fatigue and eventual failure.
I do agree that EPA needs to have all the stoves sold tested instead of using a default efficiency. Right now it is up to the stove manufacturer to have his stove independently tested and many stoves are not tested. Now to me the gram per hour rating is useless, more or less. Lets look at vehicles for a second. A diesel engine is far more efficient than a gas engine is. Now using your gram per hour rating, the diesel will actually have more emissions coming out the exhaust than the gas engine will. However the diesel is more efficient. Same with wood stoves. Efficiency and g/hr are two separate things. You could have one stove at 80% efficient and putting out 6 g/hr, and another stove that is 40% efficient and yet only putting out 2 g/hr. Hard to choose a stove from just one aspect. Here is a list of efficiency's both default and tested from the EPA http://www.epa.gov/Compliance/resources/publications/monitoring/caa/woodstoves/certifiedwood.pdf
You do not need a huge firebox for use in a cat stove. Not sure where you got that from? The reason the blaze king has a huge firebox is longer burn time (more wood more heat, longer), and they are sold in cold climates where hardwood can only be bought as part of an axe or sledge hammer. The west has a choice of pine, aspen, or cottonwood. We do not have the oak, hedge, locust many others do. So less BTU wood means you need more wood to get a all day burn. So large firebox and high efficiency stoves are a must. Well unless you never leave the house? Guys with the hardwoods try filling your stoves with pine and see how long your stove will heat with a load, I am curious. I might actually start at thread like that...hmm.
I fall into the category of try it before you buy it. I am no expert. Bring some wood that you currently burn and find a stove dealer that has one burning and properly installed. Try it out, play with it. Start from a cold firebox to see how hard it is to get a fire going, add a full load of wood to the box and see how long it provides good heat. I did this and that is why I picked a Blaze King. Many stoves were cheaper by a lot, however I plan on having this one a good many decades. Would you buy a car without test driving it? I would never buy a stove I could not burn first. I would hate to spend thousands on a new stove just to get it home and find out my old stove out performed the new one!
Here I typed this whole thing up and you guys beat me to the punch already!!
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