How much can a hot air balloon lift?

How much can a hot air balloon lift?

If you heat that air by 100 degrees F, it weighs about 7 grams less. Therefore, each cubic foot of air contained in a hot air balloon can lift about 7 grams. That’s not much, and this is why hot air balloons are so huge — to lift 1,000 pounds, you need about 65,000 cubic feet of hot air.

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