
Modern vapor compression systems are green technology for a number of reasons like utilizing eco-friendly refrigerants and their higher operating efficiency. It is a well-known fact that vapor compression systems are the most efficient means of cooling. Every increase in efficiency reduces the amount of energy used and, by extension, reduces the carbon footprint of the device being used. Efficiency in every system matters. Coal-fired power plants will release 2.1 pounds of CO2 into the environment for every kWh of energy produced. This means that every increase in efficiency directly translates to a reduction in greenhouse gas production.
Let’s compare a small-sized thermoelectric and vapor compression system to determine the environmental impact of the devices. In this example, we compare two 500-watt cooling systems. The vapor compression system has a Coefficient of Performance (COP) of 2 and the thermoelectric system has a COP of 0.4. These are typical values. The power draw of the compressor-based system is 5 times less than its TEC-based counterpart. In one hour, this means that the TEC-based system will consume 1kWh of energy. The Compressor-based system will only consume 250 kWh of energy. Over an expected product life of 5 years, the TEC-based system will release over 27 thousand pounds of CO2 into the environment. This is 21,800 more pounds of CO2 released into the environment than caused by the compressor-based system over the same timeframe. The compressor-based system would need to run for 25 years before releasing that amount of greenhouse gas. This difference gets even greater if a 10-year product life is assumed. The fact is that the inefficiency of TEC-based cooling causes the excessive and recurring release of greenhouse gases into the environment. The typical difference in greenhouse gas release is 5 times that of a vapor compression-based system performing the same cooling task. Two other factors make vapor compression the cooling system of choice when “Going Green.”:
1) Compressor-based systems undergo a refrigerant recovery process at the end of life, preventing the release of refrigerant to the environment
2) With the current switch to low Global Warming Potential (GWP) refrigerants happening worldwide, there is no longer a defensible argument that compressor-based systems harm the environment. It is apparent that vapor compression is the green technology for the foreseeable future.

For notes on how Aspen Systems assures no leakage of refrigerant from our systems, see our blog on reliability.