Building Flush out for naturally ventilated building

Hi Pratik, you'll need to use temporary equipment to complete the flush out. Page 387 of the Reference Guide says the following: "The flush-out procedure assumes the use of the building’s HVAC system, but alternatives are acceptable provided they meet the air quantity, temperature, and humidity requirements. One approach is to place temporary supply and exhaust systems in windows or other openings. The EPA’s Indoor Air Quality for Schools website provides helpful information on exhaust and spot ventilation during construction activities (see Resources, below)." However, I'd also note that interior painting alone does not meet the definition of a "facility alteration or addition". See the FAQ above. If you're just painting during the performance period you can still earn this credit - you'd need to develop a compliant IAQ Plan but would not need to perform a flush out.