During scorching heat waves, maintaining a cool home becomes a priority. One effective yet often overlooked method is plugging the chimney. Chimneys, designed to vent smoke, can act as open conduits for hot air to enter and cool air to escape, undermining efforts to keep indoor spaces comfortable. By sealing the chimney, homeowners can significantly reduce unwanted airflow, helping to maintain a cooler indoor environment.
Plugging the chimney offers multiple benefits beyond temperature control. A key advantage is the reduction of air changes within the home. During hot weather, chimneys can facilitate the influx of warm, humid air, forcing air conditioners to work harder. By sealing the chimney with a breathable Chimney Sheep, airflow is minimized, stabilizing indoor temperatures and reducing energy costs. This also enhances the efficiency of cooling systems, as less hot air infiltrates the home.
The University of Liverpool found that an open chimney can result in a 63% increase in discomfort hours during summer in a refurbished house compared to the same house with either a Chimney Sheep or a blocked chimney. Discomfort hours are a measure of how many hours during a period of time internal temperatures exceeded 26.8°C i.e. the duration of discomfort. As they say in their report: "Not only can an open fireplace let heat escape through the chimney in winter, but that it can also, in the summer, allow warm air to enter the occupied space. Therefore, sealing the chimney during summer is just as important as blocking it during the winter".
Another critical benefit is the reduction of indoor pollution. Heat waves often exacerbate air quality issues, with higher levels of dust, pollen, and pollutants circulating outdoors. An open chimney increases the number of air changes, thereby increasing the amount of polluted air that enters the home. By plugging the chimney, homeowners can limit the entry of these pollutants, maintaining cleaner indoor air and protecting household health.
In addition to sealing the chimney, several other strategies can help keep homes cool during a heat wave. Closing blinds or curtains during the day blocks solar heat gain, while using fans strategically can improve air circulation without relying solely on air conditioning. Insulating walls and the attic prevents heat from seeping in, and sealing gaps around windows and doors further reduces hot air infiltration. Finally, cooking using appliances like microwaves instead of ovens minimizes indoor heat generation, and of course we can eat more salads and foods that need less cooking.
By combining chimney sealing with these cooling strategies, homeowners can create a more comfortable, energy-efficient, and healthier living environment during extreme heat. Taking proactive steps not only enhances comfort but also mitigates the challenges posed by heat waves, ensuring homes remain a cool sanctuary.
