There are two responses to this problem: improved devices for
using biomass fuels, or the use of alternative fuels and devices for
providing these energy services. An improved wood-burning cookstove
improves efficiency by controlling the flow of air into the
combustion process and by improving heat transfer from the fuel
and hot combustion gases to the cookstove. Some improved stoves
also have a chimney to remove the combustion products from the
kitchen.