IDAF - What is your heat source? 5. May 2022 Soumaya-Khreiss VZ21 Zurich Wetzikon, My heat source (0) Task 2 We have an outdated heating system at home that runs on oil. Because the oil costs are extremely high, we never heat it in the summer. Another way would be to use less energy would be to ventilate the house. Soumaya
