A person with no knowledge of the potential for carbon monoxide poisoning brings their generator onto an enclosed porch during a power outage following a hurricane. The porch has a volume of 7,000 ft3 and a ventilation rate of 0.5 ach. The ambient and initial indoor CO concentrations are both zero. After one (1) hour, the CO concentration is 80 mg/m3. Calculate the emission rate of CO from the generator in mg/minute.