Welcome to the forum Chait13. Well, I am no expert in thermodynamics or physics in general, I just acquire a bit of practical experience in wood stove heaters from trial and error! I wish I would have some more measurement equipment to make some tests to my stoves, but hey, I do this as a hobby...At least I have one of those "cheapo" laser gun thermometers. What you can find in this forum is a lot of different ideas about the rocket stove used as a heater, probably some of these ideas can be adapted to cookstoves. There are here a couple of ideas as a cookstove as well. I think there is a big difference between a rocket stove heater and a rocket cookstove. Both intend to get high efficiency from wood burning but in the first you can achieve this goal throughout all the stove components and you want heat dissipation to the environment, on the second type, you want heat concentrated in a particular spot, in other words, under the cooking pot. For example, I am not sure that a vortex is a good technology to incorporate in a cookstove, but secondary air may be a good idea (a vortex extends the distance that fire burns and you want fire under th e cooking pot). Probably if you use a shorter risertube, even a vortex is a good idea. I do not know, only by experimenting... If you go to youtube you can also see lots of good ideas for rocket stoves.