I ran my 7500w gen ten ft outside my house, my Co alarm tripped as the
wind was blowing fumes back in. Running it in an attached space is high
risk even with doors open. Best is a sepatate shed- garage with 20 -30+
ft proper cable.
Generators are inneficent engines and can at full load consume the same
15 hp it takes to power a small car at 55mph. Also most homeowner gens
run at a less efficient 3600 rpm rather than a cars, apx 1800 at 55 mph.