Keep an eye on that AC

picture of central air conditioner outside a home
Our central AC unit.

Yes, we have central air-conditioning in our home, a modest, three-bedroom, 1,600 foot home in Aurora, Colorado, where, unfortunately, the last decade or so, summers have typically seen long, extreme hot spells, for instance, up to five weeks in a row of daily highs that exceed 90 degrees Fahrenheit, as well as a considerable number of days that top 100.

This means that especially on our second floor temperatures can push the upper 80s, even at night.

Outside air temperatures typically drop fairly quickly to reasonably cool levels on Colorado’s Front Range, even on 90-degree and 100-degree days, usually falling into the 60s or even 50s.

So, why would we “need” air conditioning?

Unfortunately, because our home – and especially our attic — like pretty much everyone else’s, acts as giant heat sponge during the day. And it takes hours and hours for that heat to radiate back off the house at night.

So, even when the temperatures outside are perfectly comfortable, say, in the mid-to-upper 60s, and even with fans in the windows, it takes hours and hours to cool the interior of the house to something approaching the very comfortable outside temperature.

AC only when it’s truly hot
We “need” air conditioning on those days on which the high reaches about 97 degrees or higher mostly so that we – and our two young children – can fall asleep reasonably easily.

Typically, we don’t turn on our home’s AC until the temperature on the first floor reaches 80 degrees, and the temperature upstairs is about 83 degrees.

This summer – which, amazingly, is one I’ve heard some people complain about – we have not turned on our central AC unit a single time.

Not once.

That’s because, for the first time since I can remember – and we’ve lived along Colorado’s Front Range (which includes Pueblo, Colorado Springs, Denver, BoulderFort Collins, or around three million people) for 13 summers now, we have had, “temperature wise”, a truly average summer. and

This fact – and it is a fact – seems to have been lost on those Front Rangers who have complained about the “cool” summer and who apparently live for 98-degree heat.

graphic of average annual temperatures for aurora, COIn fact, the average daily high in Denver should be 83 degrees in June, 90 degrees in July, and 87 degrees in August.

Thankfully, these types of average temperatures are pretty much what we’ve seen during the summer of 2009 – which, again, contrasts starkly, and positively — with previous summers.

Pretty much for all of the 12 summers we’ve been here, I remember long, extended, ridiculous hot snaps of much-higher-than-average daily high temperatures

Front Range summer of 2009 an AC free one for us
The arrival – finally – of an average Colorado Front Range summer has allowed us to go AC free so far, and I know we’ll make it through the entire summer of 2009 without turning it on once.

Yes, there have been a few moments of minor discomfort. But these have been brief.

In fact, the question of when to turn AC on, for how long, to what temperature, etc., revolves largely around the issues of discomfort and “need”, and for what seem to be a minority, the cost of the electricity.

Apparently, for some, anything above 72, or maybe 73 degrees is completely intolerable. Many of our neighbors – who’ve been regularly running their central AC this summer – appear to be among this group.

I do understand that different homes have different sun exposures. Our home, ironically, with a giant, solar-friendly south-facing roof, is actually relatively cooler in the summer than some others. This is largely because we have no south-facing windows that allow direct sunlight to enter the house during the summer.

Still, when the outside air temperature is in the low 80s, or even high 70s and I walk outside and hear my neighbors’ AC units cranking, I wonder:


Roaring AC units – even on cool nights
Their AC units often roar late into the night, even as the outside temperatures drop into the 60s and 50s!

It seems like such an incredible waste.

Open the windows!

And, if you need to, pop a fan in, suck in the breezy, cool air – and save a ton of energy, not to mention money!

Of course, I’ve never actually discussed my ideas with neighbors. That’s a bit too pushy – even for an activist like me.

Suffice to say, the less you run your home’s AC, and the more attention you pay to outside weather conditions, which, in many places such as the Mountain West, can change very quickly, the better.

If you pay attention to shifts in weather, and temperature, you can turn off the AC as soon as you don’t “need” it anymore and pop a fan into your window.

Turn off the AC – and save more for the Ride
Believe me, this will save a lot of your annual solar-generated electricity so that you have more  to charge your EV “Ride”.

You can also turn your thermostat up a degree, or two, or three – depending on your “needs.” Every degree you turn it up will result in significant energy, and money, savings to you.

You don’t need to be “extreme”  in terms of your AC or swamp cooler to save electricity and money, like some claim.

In dry places like Colorado, you can go with a so-called “swamp cooler” rather than an AC unit. Swamp coolers are quite a bit more energy efficient than AC, and they work effectively in places with dry air, such as Colorado – and Nevada, New Mexico, Arizona, etc.

We “go” with AC because our house’s previous owners put in a new unit 2004. At least it’s an efficient unit, and they signed up for the Xcel Energy “switch-off.” This sees Xcel power down your AC unit for five or 10 minutes during peak periods of electricity demand so that its overall system capacity isn’t over-taxed. In return, we receive a $40 annual rebate from Xcel.

You don’t need to be “extreme”  in terms of your AC or swamp cooler to save electricity and money, like some claim.

Being energy conscious doesn’t mean being uncomfortable
This claim really irritates me, the contention by some that anyone who takes any sort of energy efficiency measures such as turning up the thermostat in the summer and the heat down in the winter is some sort of “enviro extremist” who, by taking this sort of action, threatens to send the world back to the Middle Ages.

When it’s truly hot in our house, we run our AC to cool the downstairs to 77 during the day, and 75 at night.

The thermostat powers the AC on at 1 p.m. – if the downstairs temperature is higher than 77, and it turns the AC off at 12:30 a.m. At which point, it’s plenty cool outside to open up the windows and pull in lots of cool air with fans, even during the hottest of hot Colorado summer heat streaks.

You can survive 78 degrees in your home, or higher – and you won’t be extremely uncomfortable. And you won’t be sending the modern world back 400 years with the few beads of sweat your body might produce.

How’s that for the ultimate contradiction? The more you cool things off at home, the hotter they get globally, and the more you need to cool things off at home!

I’d say you’ll be doing just the opposite  if you turn down the AC, and, as often as possible, forego AC entirely: You’ll be pushing the world ahead.

That’s because turning down the AC also turns down global warming.

Ironically, global warming contributes to the high temperatures which “require” one to turn up the AC in the first place.

In other words, our cooling machines are heating up the earth’s atmosphere, requiring us to cool off even more – and heat the atmosphere even more.

How’s that for the ultimate contradiction? The more you cool things off at home, the hotter they get globally, and the more you need to cool things off at home!

Of course, we could eliminate this contradiction if, instead of using fossil fuels to fire those air conditioners, we used sun, wind and other renewables.

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