A cooling challenge in a warming world

In a warmer,  richer world,   the demand for air conditioning will  skyrocket.    From 900 million room air conditioners 

in 2015, the global stock is expected to grow to 2.5 billion units in 2050.  In many partsof the developing world, cool 

dehumidified air is not only a matter of comfort but also one of publichealth and safety. Cooling makes possible eco

 - nomic growth and prosperity.     The challenge we have beforeus is how to deliver that cooling sustainably to more 

people.

Most of the cooling equipment that will be in place in 2030 has yet to be manufactured, sold, and installed.With an ex

 -pectedamendment to   the  Montreal  Protocol      requiring that countries ramp down their use of hydrofluorocarbon 

(HFC) refrigerants,  the future of cooling must be one of greater energy  efficiency and climate-friendly refrigerants.

Heat pump just use such climate-friendly refrigerants . One important characteristic of refrigerants is the environmen

-tal impact that is caused if they are released or  leaked from the heat pump.   To estimate this,   indicators as ODP, 

GWPand TEWI are commonly used.  In the operation of heat pump systems,  there are direct contributions of green

-house gases from refrigerant leakage and indirect contributions resulting from the energy supply required to run the 

systems over their normal lives.    The sum of the direct and indirect emissions of greenhouse gases represents  the 

Total Equivalent Warming Impact  (TEWI)  ofthe technologies being compared.    The calculated TEWI is sensitive to 

assumptions on the system lifetime,   emission losses,  and the integration time chosen to calculate the GWP values

and, of course, the use of drive energy.