Good points. I think the problem the stove manufacturers are dealing with is two sided. On the one hand they want to extract as much heat as they can out of the wood. On the other hand, they are required to meet EPA regulations. This is a similar problem to what the car manufacturers have to deal with in their engine design balancing power output with emmissions requirements.
I understand your point of using refractory material to line the firebox to reflect the heat. Yes, this helps keep the center of the stove hotter and helps to burn clean. However, you have to be careful here because if you insulate too much all of the heat will exhaust up the flue and nothing will heat up the exterior surfaces of the radiant designed stoves. How much do you need? I don't know, I am not a stove designer, but I imagine the best companies are using a combination of thermal modeling and testing to evaluate new designs. The design needs to able to transfer the heat into the room and not up the chimney.
I am not saying one design is any better than another. They all have their pros and cons. I didn't buy my stove because I thought it was the best or most efficient design. Actually, my reasons for selecting it were (in order) quality, reliability, durability, resale value. (Notice, efficiency of the design was not even a consideration as I don't feel any design currently on the market is significantly superior.) The cons of using only fire brick is that you lose durability and aesthetics. Jotul has chosen to use cast iron panels partially for protection. It makes a more durable stove albeit at a cost.
99% of stove manufacturers are reactionary in their designs. The EPA forced them to change. These space heaters are all still really low technology. I laugh everytime I read an article about a high-tech modern EPA stove. What's high tech? I agree with you that there is plenty of room to grow these designs. 75% efficiency is not impressive. A condensing NG boiler runs at 90-95% and burns so clean you can practically vent into your house. We also have a 250 year supply of NG in our own country, but that is a different issue.
I cringe everytime somebody claims burning wood is clean and carbon neutral. How do they figure? First off you have a living tree acting as a filter for the environment and you cut it down. Great, that makes a lot of sense. Let's cut down all the forests in the world with 2 stroke chainsaws burning oil, move the wood in diesel trucks, and then process the wood with an engine powered splitter. Then let's burn that 'green' fuel in our 'clean' stoves. See what that does to our air quality. Okay, I am exagerating, but you see my point. People burn wood because it is cheaper than burning oil and the fuel is readily available in our country, but it is most definitely not sparkly green, clean, or carbon neutral.
...so to bring this post back on topic, it is for these reasons that the EPA will continue to scrutinize our cough, cough 'clean' wood burners and continue to press manufacturers to develop better solutions. The auto industry didn't add cats and smog pumps to their cars voluntarily either. I like burning wood as much as the next guy, but you have to be honest about its true impact on the environment.
I understand your point of using refractory material to line the firebox to reflect the heat. Yes, this helps keep the center of the stove hotter and helps to burn clean. However, you have to be careful here because if you insulate too much all of the heat will exhaust up the flue and nothing will heat up the exterior surfaces of the radiant designed stoves. How much do you need? I don't know, I am not a stove designer, but I imagine the best companies are using a combination of thermal modeling and testing to evaluate new designs. The design needs to able to transfer the heat into the room and not up the chimney.
I am not saying one design is any better than another. They all have their pros and cons. I didn't buy my stove because I thought it was the best or most efficient design. Actually, my reasons for selecting it were (in order) quality, reliability, durability, resale value. (Notice, efficiency of the design was not even a consideration as I don't feel any design currently on the market is significantly superior.) The cons of using only fire brick is that you lose durability and aesthetics. Jotul has chosen to use cast iron panels partially for protection. It makes a more durable stove albeit at a cost.
99% of stove manufacturers are reactionary in their designs. The EPA forced them to change. These space heaters are all still really low technology. I laugh everytime I read an article about a high-tech modern EPA stove. What's high tech? I agree with you that there is plenty of room to grow these designs. 75% efficiency is not impressive. A condensing NG boiler runs at 90-95% and burns so clean you can practically vent into your house. We also have a 250 year supply of NG in our own country, but that is a different issue.
I cringe everytime somebody claims burning wood is clean and carbon neutral. How do they figure? First off you have a living tree acting as a filter for the environment and you cut it down. Great, that makes a lot of sense. Let's cut down all the forests in the world with 2 stroke chainsaws burning oil, move the wood in diesel trucks, and then process the wood with an engine powered splitter. Then let's burn that 'green' fuel in our 'clean' stoves. See what that does to our air quality. Okay, I am exagerating, but you see my point. People burn wood because it is cheaper than burning oil and the fuel is readily available in our country, but it is most definitely not sparkly green, clean, or carbon neutral.
...so to bring this post back on topic, it is for these reasons that the EPA will continue to scrutinize our cough, cough 'clean' wood burners and continue to press manufacturers to develop better solutions. The auto industry didn't add cats and smog pumps to their cars voluntarily either. I like burning wood as much as the next guy, but you have to be honest about its true impact on the environment.