Can we open only one window for ventilation

Opening only one window for ventilation usually has limited effectiveness. It is recommended to open the opposite window at the same time to create convection. The effect of window ventilation is mainly related to factors such as air convection intensity, outdoor air quality, indoor space layout, seasonal climate conditions, and pollutant concentration. When opening windows for ventilation, only opening single-sided windows can cause slow air flow and lower indoor and outdoor air exchange efficiency. In this case, the speed of fresh air entering the room is slow, making it difficult to quickly dilute indoor pollutants such as carbon dioxide and formaldehyde. Especially in newly renovated rooms or densely populated areas, single-sided windows may not meet the ventilation needs. But if the outdoor wind is strong or the window is located on the windward side of the building, a single-sided window can also achieve a certain ventilation effect. When there is a large temperature difference between inside and outside the room, opening the opposite window can create a through draft, using the principle of hot air rising to accelerate air circulation. This convection method can complete indoor air renewal in a short period of time, significantly reducing the risk of respiratory infectious disease transmission and eliminating cooking fumes. But in hazy weather or street facing rooms, it is necessary to use air purification equipment to prevent outdoor pollutants from entering.

It is recommended to prioritize fresh air in the morning and evening for daily ventilation, with each ventilation session lasting around half an hour. During winter ventilation, it is advisable to reduce the window area but increase the frequency to avoid sudden drops in indoor temperature. For poorly ventilated rooms, exhaust fans or fresh air systems can be used in conjunction to enhance ventilation efficiency. Special populations such as asthma patients should avoid direct contact with cold air and intermittent ventilation can be used.