Three Planets
Today humanity uses the equivalent of 1.6 planets to provide the resources we use and to absorb our waste.
Moderate UN scenarios suggest that if current population and consumption trends continue, by the 2030s, we will need the equivalent of two Earths to support us.
Should the global population reach 9.6 billion by 2050, the equivalent of almost three planets could be required to provide the natural resources needed to sustain current lifestyles. All of us bear the responsibility for the terrible legacy we are leaving to our grandchildren.
The refrigeration sector (including air conditioning) currently consumes about 17% of the overall electricity used worldwide. Of this, industrial refrigeration accounts for about 16% globally or almost 3% of world energy consumption. Globally, 440 kWh/year/capita are spent for refrigeration purposes. This figure varies from 76 in Sub-Saharan Africa to 2,697 in North America. Around 20% of the global-warming impact of refrigeration systems is due to direct emissions (leakage) of fluorocarbons while the remaining 80% is due to indirect emissions originating from the electricity production of fossil fuel power plants required to power the systems
We can all play a part in improving the lot of our grandchildren:
- Resist the temptation to build the “lowest priced” systems. Invariably these are the highest cost ecologically and, in fact, financially when the 10 or 20 year life cycle cost is calculated.
- Avoid the use of higher GWP refrigerants most of which will soon be phased out of production. - Work toward developing more natural refrigerant solutions and refining the ones we have.
- Continue to develop the industrial heat pump market & to refine our designs.
- Develop sales and communication tools to clearly and simply point out the very real financial advantages of energy efficiency.
- Take every opportunity to educate ourselves about new developments & improved technologies.
- Critically analyze all of our projects both pre and post sales with an eye to improving energy efficiency as well as reducing the “real” cost to the owner.
o An economizer will almost always improve the performance of any screw compressor system and can be financially viable even at air conditioning temperatures.
o Often, addition of an economizer will result in the possibility of using a smaller compressor for the same duty thus making the addition first cost almost neutral.
o Consider the advantages of parallel compression and new technologies such as ejectors in CO2 systems.
o Floating head pressure control always provides attractive paybacks.
o Reduce approach temperatures on both fluid cooled condensers and chiller evaporators to 3 – 4 ⁰C. This can sometimes lead to selection of smaller compressors and/or pump motors making the larger heat exchangers almost cost neutral.
o Select evaporative condensers for lowest motor kW/kW heat rejected and lowest reasonable approach to Wb temperature (usually 6 -7 ⁰C in warmer climates and up to 10 ⁰C in colder seasonal climates)
o Consider air cooled condensers or a combination of air cooled and evaporative condensers with unit mounted pumps in cooler climates or anywhere water is a premium resource.
o Look seriously at the mobile fleet. Consider lighter, more efficient cars, smaller service vans or diesel fueled service trucks. Look at hybrid vehicles for inner city duty and/or utility trailers for the times we need to carry larger items. Clearly, we as refrigeration experts working in in the most energy intensive market in the world have an opportunity or, in fact, an obligation to improve the energy efficiency of the systems we design and build so as not to leave our grandchildren a legacy of a depleted planet with a drastically reduced quality of life as compared to ours.
C. M. Noseworthy P. Eng.