Some of my favorite lung herbs are nettle leaf, watercress and mullein leaf. If their is mucous in the lungs then fenugreek can help break up the mucous and horehound or osha' can be used as an expectorant.
Can you see these all in one formula (of ground herbs)
taken as a supplement (in the raw: a spoonful)through the 'air-con' season?
These can be combined. Mullein leaf though is rather "hairy" so it is hard to get down in powder form unless in a capsule. Otherwise the little hairs tend to get stuck in the throat. And osha' is hard to find, especially in powder form. You can always leave these out since the other herbs will provide the same benefits. I would go with 4 parts nettle leaf, 2 parts fenugreek seed and one part each of watercress and horehound.