China　is　actively　developing　passive　houses　to　improve　energy　efficiency　and　reduce　primary　energy　use.　These　buildings　have　low　actual　load　characteristics,　resulting　in　a　smaller　air　conditioning　terminal　heating　capacity.　However,　owing　to　this　limited　heating　capacity,　the　air　conditioning　terminal　provides　modest　indoor　air　regulation.　In　practice,　occupants　of　passive　houses　often　open　windows　for　ventilation　in　winter,　resulting　in　an　indoor　temperature　that　is　lower　than　the　set　value,　and　it　takes　a　long　time　for　the　temperature　to　return　to　the　desired　level.　There　are　few　studies　that　have　investigated　this　issue.　Two　possible　solutions　to　this　issue　are　proposed:　first,　altering　the　external　wall　structure　can　enhance　the　thermal　response　rate,　reducing　the　time　needed　for　temperature　recovery.　Secondly,　limiting　the　window-opening　area　can　minimize　heat　loss　during　ventilation,　thereby　maintaining　a　reasonable　indoor　temperature.　Notably,　this　may　inconvenience　occupants.　Taking　a　passive　house　in　Qinghai　as　a　case　study,　this　study　discusses　the　influence　of　window-opening　behavior　on　the　indoor　thermal　environment.　Simulations　were　conducted　to　study　the　window-opening　behavior　considering　different　window-opening　areas　and　wall　structures.　Three　different　wall　structures　were　considered:　internal　insulation　combined　with　external　insulation　(IAE),　sandwich　insulation　combined　with　external　insulation　(SAE),　and　external　insulation　structures.　The　results　indicate　that　the　IAE　and　SAE　structures　cannot　effectively　improve　the　indoor　thermal　environment　after　opening　a　window.　Overall,　changing　the　wall　structure　does　not　reduce　the　time　required　to　restore　room　temperature.　However,　by　limiting　the　opening　area　of　the　window,　the　room　temperature　can　be　effectively　controlled.　Under　the　given　window　opening　ratio,　the　room　temperature　can　be　stabilized　above　18　℃.　This　study　offers　a　practical　method　for　controlling　and　enhancing　the　indoor　thermal　environment,　which　is　applicable　to　the　construction　and　development　of　passive　houses.　©　2024