How Many U.S. Households Don’t Have Air Conditioning?
With rising adoption, nearly 90% of American homes have air conditioning, but almost 30% in California are still without it.
And, once again, the U.S. is gripped by sweltering heat and humidity. Higher-than-average summer temperatures are everywhere, even in places like Portland, Oregon, which topped 100 degrees last weekend and in Boston, Massachusetts which declared a heat emergency in early August.
These high temperatures in the Northwest and Northeast are particularly interesting and concerning because these are the few parts of the country where many people do not have air conditioning. The percentage of U.S. households with air conditioning has been steadily increasing for decades, and today nearly 90% of households have some type of air conditioning.
But for today’s post, I want to look at the other 10%. Where are the households without air conditioning? Which states have the most households without? These patterns are important because households without air conditioning are more at risk from dangerous temperature spikes, and because this is where there is likely to be increased adoption in future years.
Keeping it Cool
The map below plots the percentage of households with air conditioning by state. This information comes from the newly-released 2020 Residential Energy Consumption Survey (RECS). Conducted approximately every 4 years by the U.S. Department of Energy, the RECS provides lots of energy-related information about U.S. households.
As the map indicates, the United States really likes air conditioning. In forty states, 80%+ of households have air conditioning. In thirty-two states, 90%+ have air conditioning, and thirteen states, 95%+ have air conditioning. Despite not being a particularly hot country by international standards, the United States has long vigorously embraced air conditioning.
Sweating it Out
Still, the map also highlights several states with lower levels of air conditioning. The table below lists the ten states with the lowest percent of households with air conditioning. Alaska is in a category by itself with only 7% of households with air conditioning. Otherwise, the percentage of households with air conditioning ranges from 53% (Washington) to 77% (New Hampshire).
There is a clear regional pattern here. New England is heavily represented (Vermont, Maine, and New Hampshire), but also the Mountain West (Wyoming and Montana), and the Pacific (Alaska, Hawaii, Washington, Oregon, and California).
These data imply that nationwide there are 14 million households without air conditioning. Of these, 3.7 million are in California. No other state comes close in terms of the total number of households without air conditioning, so the state is likely to be particularly sensitive to health impacts from temperature spikes, and is a state where we are likely to see rapid increases in air conditioning in the coming years.
Climate Correlation
As you probably already inferred from looking at the map, there is a strong correlation between air conditioning and climate. The scatterplot below explores this correlation using cooling degree days (CDDs), a widely used measure of cooling demand which reflects both the number of hot days as well as the intensity of heat on those days.
Air conditioning is ubiquitous in states with 1500+ cooling degree days per year. This makes sense. There are fixed costs of buying and maintaining an air conditioner, and households choose to bear these costs when they live in a place that exceeds a particular climate threshold.
For the same reason, virtually all of the least air-conditioned states have less than 1500 cooling degree days per year. Alaska is again a clear outlier, but Montana, Vermont, Maine, Wyoming, and Oregon, for example, are all relatively cool states where there are few enough hot days each year that many households choose to forego air conditioning.
Hawaii is a fascinating exception. The average household in Hawaii experiences 3,500 CDDs annually making it the hottest U.S. state by this measure, yet only 57% of households have air conditioning. Readers can weigh in with their preferred explanations, but I suspect the lack of air conditioning in Hawaii has to do with the housing stock. Because it tends not to get very cold in Hawaii, homes are built with less insulation, making air conditioning less effective and more expensive, particularly given Hawaii’s high retail electricity prices.
The Final Frontier for U.S. Air Conditioning
These data were collected just before the record-breaking heat wave experienced in Oregon and Washington during July 2021. It got so hot in the Pacific Northwest that people waited in long lines for a chance to buy an air conditioner, and stores like Home Depot, Lowe’s, and Walmart completely sold out. So even though these data are relatively recent, they already likely understate the current level of air conditioning in some states.
In the United States and other rich countries, household incomes are typically not the limiting factor. Instead, air conditioning adoption in the U.S. is more about climate, and about when and where average temperatures rise high enough to justify the cost and hassle of installing air conditioning.
This “air conditioning frontier” will continue to move over time with climate change. Since the 1950s, average annual cooling degrees in the United States have increased 30%. Over time, U.S. households are experiencing more hot days and higher intensity of heat on those days, making air conditioning more attractive. The U.S. is already a country with high levels of air conditioning, but there will be fewer and fewer exceptions, with widespread air conditioning even in places that didn’t have it historically.
Keep up with Energy Institute blogs, research, and events on Twitter @energyathaas.
Suggested citation: Davis, Lucas, “How Many U.S. Households Don’t Have Air Conditioning?”, Energy Institute Blog, UC Berkeley, August 15, 2022, https://energyathaas.wordpress.com/2022/08/15/how-many-u-s-households-dont-have-air-conditioning/
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Lucas Davis View All
Lucas Davis is the Jeffrey A. Jacobs Distinguished Professor in Business and Technology at the Haas School of Business at the University of California, Berkeley. He is a Faculty Affiliate at the Energy Institute at Haas, a coeditor at the American Economic Journal: Economic Policy, and a Research Associate at the National Bureau of Economic Research. He received a BA from Amherst College and a PhD in Economics from the University of Wisconsin. His research focuses on energy and environmental markets, and in particular, on electricity and natural gas regulation, pricing in competitive and non-competitive markets, and the economic and business impacts of environmental policy.
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Hawaii has less air conditioning because it seldom gets over 90 and the last time it got over 100 was 1931. It is usually in the high 70s or mid 80s. The trade winds blow most of the time. People open their windows to get a cooling breeze. While they have a huge number of degree days, people who are used to the climate seldom feel uncomfortable.
The Hawaii outlier (and in some respects California too) exposes an issue with using base 65 cooling degree days (CDD) for residential air conditioning load. Base 65 may work okay for commercial buildings (which have large solar loads, and thus a high balance point) but it is not appropriate for residential buildings in mild climates. Think about a theoretical climate that is constantly 70 degrees. This would have 1825 base 65 CDD, but would be very comfortable without air conditioning. Hawaii isn’t quite like that, but it is close, with dry bulb temperatures rarely above 75 or 80, but also rarely below 65. It would be interesting to try your plot using CDD with a 70 or 75 degree base, but RECS doesn’t have that.
Much of California’s population lives along the Pacific Coast and has very mild summer temperatures. Once you get 10 miles or more from the pacific coast, summer temperatures rise, and the use of air conditioning becomes more prevalent. 10 to 15 miles from the coast, small window air conditioners will keep one comfortable and it is only when one gets more than 15 miles from the Pacific Coast that full house air conditioning comes the standard. Our natural on shore flow, from the Alaskan gulf stream current, that has a water temperature of 54 degrees, most of the year, keeps us cooler in the summer and warmer in the winter than areas more inland. Perfect for replacing natural Gas furnaces with heat pumps and that provision has been made in the Federal legislation on tax credits up to $8,000.00 for homes where the Houshold income is less than $140,000.00 per year.
“Once the code goes into effect in January 2023, most new homes and buildings statewide will either need to be equipped with at least one highly-efficient heat pump for either space heating or water heating, or face higher energy efficiency requirements — a move that will deliver considerable climate and air quality benefits. The new code also sets stronger ventilation standards for gas stoves, after the California Air Resources Board found last year that they were a major health risk…Aug 11, 2021.” https://www.nrdc.org/media/2021/210811-0
“so the state is likely to be particularly sensitive to health impacts from temperature spikes, and is a state where we are likely to see rapid increases in air conditioning in the coming years”. This is spreading FUD.
HI Lucas: Two comments
1. Surely, humidity is a factor in how bearable heat is (I’m writing from the UK, where we recently have had two record-breaking hot spells, but low humidity, which made it bearable). Did you account for this at all?
2. It may also be important to account for the extent to which people rent their dwelling, rather than owning it. Germany stands out as one country with a high proportion of people renting, so air conditioning may not be an item that the occupant can affect.
Earlier this summer my niece bought her first house. She moved her portable air conditioners from her rental. They get turned on when the humidity level and temperature make her local northern Ohio climate feel sticky- kind of like how it is all summer long in parts of the southeast.
We bought a couple portable heat pumps this spring to dry out some of the interior spaces in our 158 year old house. Bell, Boots-our 5?year old tiger stripped cat, and the humans stay indoors a lot when things get really sticky outside. Our border collie puts the breaks on during walks when the dew point is above 60 with an air temperature around 80F.
In California the push for electrification is likely to increase the percentage of households with air conditioning, though by how much it’s hard to say. New homes built in coastal areas with moderate climates that might in the past have had gas furnaces but opted to go without air conditioning will have it by default if they are built with heat pumps. Likewise existing homes that are retrofitted with heat pumps to replace other forms of space heating will also have air conditioning by default.
Lucas, thanks so much for this study and information. You’ve presented answers to some important questions about how the US is responding to a warmer climate; getting around the problem by staying indoors. Having just returned from a couple weeks in the Scottish Highlands, I find there is very little air conditioning there. Nevertheless, when temperatures get into the mid-70’s, Scots begin to complain about it being too hot! I suppose they’ll begin installing AC too.