src: Large amounts of exhaust air movements cause large amounts of energy for the ventilation systems as well as serious heating costs during the winter, not to mention the carbon CO2 emissions.
tgt: Große Mengen an Abluft verursachen einen hohen Energieverbrauch der Lüftungsanlagen, sowie erhebliche Heizkosten im Winter, ganz zu schweigen von den CO2-Emissionen.