In a case study published in GUIDE to Natural Refrigerants in North America - State of the Industry 2015 Embraco emphasised the use of hydrocarbon refrigerants and variable speed compressor technology in light commercial refrigeration systems. The study showed both the simplicity and benefits of substituting HFC refrigerants with hydrocarbons by analysing the substitution of a HFC compressor with a conventional on-off propane compressor as well as replacing a conventional HFC compressor with a propane compressor with variable cooling capacity.
Both studies analysed energy consumption levels of plug-in vertical freezers. The first example is a glass-door vertical freezer with 14 cubic feet (0.4 m3) of internal volume and the second one is a solid door vertical freezer manufactured from stainless steel with an internal volume of 20 cubic feet (0.6 m3); both are used as cooling equipment for retail stores, supermarkets and restaurants. The selected systems were originally manufactured with Embraco compressor models NT2178GK (using R404A) and NEK2150GK (using R507).
R290 was selected as the substitute for both original refrigerants. The configurations of all the refrigeration systems tested were almost identical, with compressor and filter dryers changed for the comparative testing. In analysing the difference between HFC and hydrocarbon refrigerants (as shown further in Table 1 and Table 2), the systems using hydrocarbon refrigerants show an improved performance in all parameters.
By replacing the NT2178GK HFC compressor with one using propane in a glass door vertical freezer, the test saw a 37.5% reduction in energy consumption, while replacing the NEK2150GK HFC compressor with a propane compressor in a solid door vertical freezer yielded a 42.9% reduction in energy consumption. In addition, CO2 emissions were reduced by 41-46%.
<a href="http://refcatalog.com/wp-content/uploads/2015/10/embraco_tab1.gif"><img class="alignnone size-full wp-image-518" src="http://refcatalog.com/wp-content/uploads/2015/10/embraco_tab1.gif" alt="embraco_tab1" width="482" height="353" /></a>
<a href="http://refcatalog.com/wp-content/uploads/2015/10/embraco_tab2.gif"><img class="alignnone size-full wp-image-519" src="http://refcatalog.com/wp-content/uploads/2015/10/embraco_tab2.gif" alt="embraco_tab2" width="486" height="348" /></a>
Source: <a href="http://www.hydrocarbons21.com/articles/6687/r290_provides_significant_reductions_in_energy_consumption_over_hfcs" target="_blank">hydrocarbons21.com</a>