Executive summary: The author argues that if mirror life made outdoor air lethal, many buildings could be made survivable with rapid retrofits that combine tight envelopes, positive pressurization, and high-efficiency filtration, though key parameters remain uncertain.
Key points:
The author assumes a scenario where mirror life could render outdoor air poisonous, requiring ~99.999% particulate removal and substantial building pressurization, but emphasizes high uncertainty and need for experiments.
Effective mitigation depends on four components: a relatively airtight building, a fan to induce positive pressure, a high-efficiency filter, and a duct system to deliver filtered air.
Buildings’ leakage can be quantified (e.g., blower door tests at 50 Pa), and these measurements can be extrapolated to estimate airflow needed to maintain ~25 Pa positive pressure against wind-driven infiltration.
There is large variation in building leakiness, typical U.S. homes are relatively leaky (~4000 cfm@50Pa), and air-sealing can reduce leakage by about 1/4–1/3, though intuition about leak sources is often wrong.
If full-building pressurization is infeasible due to leakage or limited fan capacity, a “seal and cordon” strategy (isolating smaller interior zones) may be necessary.
Major uncertainties include how to source adequate fan capacity (especially outside North America), how to achieve durable ultra-fine filtration without overloading fans, and how to scale filter production and maintenance.
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Executive summary: The author argues that if mirror life made outdoor air lethal, many buildings could be made survivable with rapid retrofits that combine tight envelopes, positive pressurization, and high-efficiency filtration, though key parameters remain uncertain.
Key points:
The author assumes a scenario where mirror life could render outdoor air poisonous, requiring ~99.999% particulate removal and substantial building pressurization, but emphasizes high uncertainty and need for experiments.
Effective mitigation depends on four components: a relatively airtight building, a fan to induce positive pressure, a high-efficiency filter, and a duct system to deliver filtered air.
Buildings’ leakage can be quantified (e.g., blower door tests at 50 Pa), and these measurements can be extrapolated to estimate airflow needed to maintain ~25 Pa positive pressure against wind-driven infiltration.
There is large variation in building leakiness, typical U.S. homes are relatively leaky (~4000 cfm@50Pa), and air-sealing can reduce leakage by about 1/4–1/3, though intuition about leak sources is often wrong.
If full-building pressurization is infeasible due to leakage or limited fan capacity, a “seal and cordon” strategy (isolating smaller interior zones) may be necessary.
Major uncertainties include how to source adequate fan capacity (especially outside North America), how to achieve durable ultra-fine filtration without overloading fans, and how to scale filter production and maintenance.
This comment was auto-generated by the EA Forum Team. Feel free to point out issues with this summary by replying to the comment, and contact us if you have feedback.