Does energy from burning of gas in a hot air balloon transfer to the air around it?

The air inside a hot air balloon is heated by burning fuel (usually propane). The air is kept inside the balloon so it doesn't readily mix with the cold air outside the balloon, but there is of course energy transfer from the hot air to the fabric and then to the surrounding colder air. This is why a balloon needs to fire the burner periodically, to reheat the air that has cooled or been lost through venting (to cause the balloon to rotate or fly lower)