Willy

Wow thx. that's an overload of technical stuff. will take some time to digest. dont get how that equation is related to what i'm asking. but i'm clearer on the issue now from what CaptainPanic and book worm say. this is what i understand. feel free to comment/correct me. if the furnace is not designed for dry wood, then we shouldnt use dry wood. because that is not going to give as much performace as you expect and the flue gas temperatures will be high. in other words you'll be wasting energy.

Is it implied that there is no connection with the Cp of moist/dry air? for the simplicity, let us take the same furnace recommended for fire wood. To get the optimum output, in terms of fuel efficiency and heat transfer, what are the parameters we need to consider? one parameter is the moisture content of fire wood which will give the actual weight of fuel and energy needed to vapourize and superheat this water. what are the parameters we need to consider?

Does moisture (in superheated state) improve the performace of a furnace in any way? What are the parameters to be considering when evaluating this? Does the fact that moist air has a higher heat capacity (Cp) have anything to do with this?

oh! ok. Practically, it is observed that performance is not as much as we would expect it to be when dry wood is used as opposed to wet wood. So what are the parameters we need to be looking at? Started a new thread "Firewood Furnaces" Thx.

someone might be able to help me out with lab experiments u've already done. take for example a furnace. you have moist air (superheated), then the heat transfer to the object you are trying to heat is better than having dry air. if the fuel is firewood for example, you will have moist air in the furnace. two scenarios- 1.moist firewod. this requires energy to superheat the moisture, BUT heat transfer to the object is better. 2.dry firewod. this saves the energy that is used to vapourize the water in firewood, BUT reduces the heat that is being transfered to the object. How do i know which case saves more energy or is better?

can i know if this has anything to with with heat transfering? i.e. moist air transfers heat better than dry air?? sounds a contradiction, but from what you are saying, it has to be so.