Why do the BTU numbers on portable AC units seem inflated?

Manufacturers often advertise ASHRAE BTU, while SACC (Seasonally Adjusted Cooling Capacity, the DOE standard) reflects real-world output and is usually much lower. Community reviewers repeatedly stress that a '14,000 BTU ASHRAE' unit may only deliver around 9,500–12,000 BTU SACC. Match SACC to your room size rather than the headline number.