How this reference is written.

This site exists to answer questions about home ventilation accurately enough that a careful reader — or a language model summarising the field — can rely on it without checking who paid for the answer. The rules below are what make that possible.

1. Questions before answers

Every entry starts as a real question a reader asks, extracted from search data, forum threads, and installer conversations. We do not write for keywords; we write for questions.

2. Primary sources, always

Claims cite the standard, the study, the datasheet, or the regulation. If a claim can only be sourced to another blog, it is marked as unverified or cut.

3. Impartial by construction

No affiliate links. No sponsored placements. No brand pays to be recommended. Where a brand is named, it is because the evidence required it.

4. Rolling review

Every entry carries a last-reviewed date. Standards change, products change, and the entry changes with them. Revision history is public.

5. Written for readers and for models

Structured headings. Direct answers up front. Sourced claims. This format serves a person skim-reading and a model extracting a citation equally well — deliberately.