AC and Climate Change

Air conditioning and climate change – how can future improvements help our environment? Efforts to reduce the impact of air conditioning on climate change continue with focus on new refrigerants, increased efficiency, and new technologies. A recent National Geographic article caught my eye because it predicts that deadly heat waves could affect ¾ of the world’s population by the year 2100. Deadly heat wave are not new – we have seen them recently across the world. For instance, more than 70,000 people died in Europe in the 2003 heat wave, and many of the world’s large cities (including New York City) have experienced lethal heat. The very old and very young are most vulnerable to the effects of extreme heat. The danger due to a small increase in temperature is worse in humid environments. While 1 degree Celsius seems like a small increase in global average temperature, it results in environments that are uncomfortable, and even unsafe, without air conditioning. In places like California, Washington, and Oregon, where residential air conditioning use has historically not been widespread, the number of households with some type of air conditioning (central or window units) has doubled since the 1990s.

It’s clear that air conditioner use will continue to increase. As I mentioned in an earlier blog, the projection is for 1.6 billion new AC units to be in use by 2050 throughout the world. One area of focus for the air conditioning industry is to find more environmentally friendly replacements for our current refrigerants that deplete the ozone and/or emit greenhouse gases. The ideal refrigerant will be safe, nonflammable, not deplete the ozone, not be a greenhouse gas, and will be cost effective to produce and use. The search continues!

Another area of focus for the air conditioner industry is increased efficiency of air conditioning units. Those 1.6 billion new AC units will require new coal burning, greenhouse gas emitting power plants to operate them. Increasing efficiency will mean fewer plants will be built. Currently, air conditioner operation consumes about 14% of energy used in the United States. Most air conditioners built before 2006 have SEER ratings of 10 or lower, but newer units come with better ratings. (SEER stands for Seasonal Energy Efficiency Ratio, and measures cooling output in relation to electrical energy input to achieve that cooling. The higher the SEER, the more efficient the unit is.) Trane’s most efficient air conditioner can achieve up to 22 SEER, with savings of 64% in energy cost. It is expected that air conditioners will continue to increase in efficiency.

Research also continues into innovative cooling techniques. Perhaps future air conditioners will use a completely different technology than today’s air conditioner, which removes heat from the air by blowing it across coils cooled by refrigerant. Researchers at the National Renewable Energy Lab (NREL) in Golden, CO, have working demonstrations of a new technology called DEVAP that uses desiccants to dry humid air which is then cooled through evaporation. This process completely eliminates the use of conventional refrigerants. Removing humidity is key to comfort, and that is something that today’s air conditioners don’t do very efficiently. Savings of up to 30-80% less energy over today’s most-efficient air conditioners are possible because DEVAP only has to power small, efficient fans and pumps. Likely, this new technology would be licensed to the HVAC industry with commercial products developed first, followed by products for homes.

As cooling season winds down in Boulder County, Colorado, there’s still a little bit of time to make sure your air conditioner is running well. Remember that it is important to our environment to make sure your AC unit is running as efficiently as possible with no leaks. We can squeeze in a few more tune ups before the fall chill hits. This is also a great time to think about whether your furnace is ready for winter. If you haven’t scheduled a furnace tune up yet, please schedule here or call 303-435-8141.