“Perhaps the landlord will be open to discussion if the heat builds up unbearably in the house and consider converting to a central system,” says Schossig. The large systems, such as those found in office buildings and hospitals, are usually not as bad as their reputation suggests. “They often release the heat into the groundwater or soil via a geothermal probe,” says Schossig. More and more users are also relying on using the heat and cold of the air conditioning units equally, for example in hospitals. Waste heat is excellent for sterilizing surgical instruments or for heating water in the laundry.
Refrigerants are a major problem for the climate and the environment
It sounds as if Willis Carrier thought up a miracle machine rather than a hell machine back then – doesn’t it? Soon after being granted his patent in 1906, Carrier set about developing his invention further. Instead of using cold water, he then used ammonia as the circulating refrigerant. But ammonia has one major disadvantage: it smells pungent and is poisonous.
In the 1930s, synthetic refrigerants based on halogenated hydrocarbons were therefore increasingly used. They are non-toxic, flame retardant and cheap to produce. However, it quickly became apparent that chlorofluorocarbons (CFCs) destroy the protective ozone layer, and depending on the substance, hydrofluorocarbons (HFCs) have a greenhouse gas potential that is up to 24,000 times higher than that of carbon dioxide, expressed as GWP (Global Warming Potential). “The refrigerants currently used in over 95 percent of air conditioning systems are extremely harmful to the climate,” writes the Federal Environment Agency.
Although the gases usually only escape from the cooling circuits in small quantities, “Synthetic refrigerants and outdated systems cause significant greenhouse gas emissions – eight million tons of CO2equivalents in 2020,” said the President of the Federal Environment Agency, Dirk Messner, recently. While CFCs have been banned in the EU since 1995, the use of HFCs has only been gradually restricted since 2015.
Peter Schossig praises the European Commission’s so-called F-Gas Regulation. “The regulation is very effective, but so far this determination has been limited to the EU,” he says. By gradually reducing the quantities of HFCs available on the market, their emissions are to be reduced to 35 million tons of CO2-Equivalent to decrease by 2030. A text amendment to the regulation presented in April provides for the measure to be tightened even further.
The idea behind it: getting the industry to develop – and use – alternatives. However, with the recent amendment to the Montreal Protocol, an international agreement, many other countries have also committed to progressively reducing HFC production. “Technically, it would already be feasible to use natural refrigerants in many applications with a GWP of 0 to 4 instead of 4000 or more,” says Schossig. In addition to ammonia, these natural alternatives also include CO2, hydrocarbons such as propane and isobutane, air and water. “However, they all have some disadvantage – they are either toxic, flammable, less compressible or freeze at 0 degrees.”