On behalf of the Umwelt- und Gesundheitsschutz Zürich (UGZ), we calculated the environmental footprint of various heaters such as patio heaters/ mushroom heater with gas or pellets, electric radiators, heatable seat cushions and blankets. The following findings were derived: Blankets are the most environmentally friendly under the assumption that they only need to be replaced and washed once a week. If heating is to be used in the outdoor areas of catering establishments, it should be with electric radiators powered by certified eco-power or with seat cushions. Heating with pellet heating mushrooms is less convincing. Heating with liquid gas mushroom heaters or electric heaters powered by Swiss electricity mix is not recommended.
Note regarding legal basis and choice of variants: Outdoor heaters are only permitted in the Canton of Zurich if they are powered by renewable energy or waste heat that cannot be used in any other way. The recommendations made herein refer only to the ecological assessment and not to legal framework conditions.
In the factsheet Heating options for outdoor catering, only the life cycle assessment results are based on our study, while legal and economic aspects were assessed by the UGZ itself.