# The World’s Most Efficient Air-Conditioner

## By Mr. Money Mustache

## Thu, 14 Jun 2012 17:39:16 +0000

Well, I’m finally done building that fence I’ve been meaning to build for the last few years. It came out great, and now we at last have the nice, private yard that this house of ours deserves. But as with every do-it-yourself project, other unexpected benefits were revealed as well, and one of them was that I ended up with a free air conditioner of unsurpassed efficiency.

To get this fence built Mustache-style, I didn’t whip out my cell phone and credit card and call a fence contractor. I had to do it myself, and since it was my first large-scale fence (about 180 linear feet at 6 feet of height), I kept track of some of the stats.

I had to set 25 posts of treated lumber into the ground. The posts were each 8 feet long, weighing 30 pounds each and set into about 80 pounds of concrete. Of course, before setting each post I had to carefully line up and carve a 2-foot-deep hole in the rocky, dry Colorado hardpan soil. Each of those 80-pound piles of excavated soil and rocks was the result of several minutes of wrestling with a burly electric drill equipped with a 3″ soil auger (a very useful invention!) followed about 100 blows with a manual post-hole digger, and occasional attacks with a sawzall to cut through roots, a diamond blade grinder to cut through concrete, and a handheld jackhammer to chip away anything that remained. And all those holes were just to get me to the point of hand-mixing over 2000 pounds of concrete, manually tailoring, drilling and screwing over 100 cross pieces, and nailgunning in 500 cedar planks, cutting and bending each to coax their naturally-curvy demeanor into the extremely tight and straight fence that I wanted.

All in all, it was about 69 hours of work, and it was done through a period of record temperatures in my area. Some days topped out at over 100 degrees Fahrenheit (37C), and few were below 80. Half of the fence is in full sun, leaving me with only SPF 80 sunscreen and my sun hat for shelter.

But a strange thing happened as the days went on and the fence sections were completed, one after another. I stopped noticing the heat, and started feeling downright comfortable. The improvement was so dramatic that I thought it was the weather that was changing rather than me. Often I’d walk past my outdoor thermometer on the way to refill my water mug, and be shocked to see another mid-nineties reading, when I felt like it was under 80. And at the end of each day, I’d find myself inside the house feeling comfortable even with a shirt on, noticing an indoor thermometer reading above 85. In previous years, I had felt the need to turn on the air conditioner at around the 80 mark. Morning house temperatures in the high 60s suddenly felt bone-chilling to me, even though in the winter I normally curse the stuffy house and go outside to get some fresh air if someone turns the thermostat above 67.

What I had done with all this work in the heat is given myself the gift of Heat Acclimation. This is a form of Badassity that is not just something made up by the most spartan of Mustachians. It’s a real and scientifically measurable body adaptation – a gift of comfort that YOU should give yourself this summer, because the benefits are enormous.

To get some of this goodness for yourself, it helps to understand what it is.

When a normal office worker encounters unusual heat, his body tries to cool itself by sweating. The body also circulates heated blood out near the skin’s surface, allowing heat to radiate and convect through the skin and evaporating water. That’s why overheated people often appear more reddish in color.

The problem is that this leaves less blood in the core of the body where the muscles are working, and it requires a higher heart rate for any given volume of work. In short, you slow down at whatever you are doing, and if you push too hard you start feeling like shit and just want to lie down in the shade.

But when you’re out in the heat, your body is starting to wise up to the situation. It creates more blood, the endurance of your sweat glands increases, and the ability to sweat efficiently at the first sign of heat increases. You really do become a Badass Heat Survival machine, and research indicates that you’ll see significant results within just one week of spending an hour or so outside in the heat doing light exercise like walking or biking. I’d estimate that my own acclimation has sliced about 12 percieved degrees Fahrenheit off of this summer’s heat.

The more you do it, the better you get, as witnessed by the Phoenix-area MMM readers who insist that they can easily bike to work year-round in that hot desert city where daytime highs are rarely below 40C (104F) for months on end. This also explains the amazing abilities of my Mexican concrete subcontractors back in the house-building days. These guys would often work alongside me on searing-hot days in black jeans and long-sleeved Denver Broncos sweatshirts, while I could barely survive with a white t-shirt, dark sunglasses, and enormous straw sombrero.

In other words, when someone says, “You can’t spend time outside where I live, it’s TOO HOT!”, it’s really equivalent to saying, “You can’t bike to the grocery store where I live, IT’S FOUR MILES AWAY!” – it’s not a question of impossibility, just of acclimation.

But this post isn’t really about extreme heat survival, like those 120F Phoenix days. It’s about a much easier and more relaxing kind of heat acclimation – making the most out of your own climate in the summer months.

During the peak of the last hot season, I wrote a rant called “How Not To Use Your Air Conditioner“, where I railed on the excessive use of A/C by modern people. This year, I’m doing it again, but with the added perspective of this new experience of extreme heat acclimation, because it works better than I thought.

Here’s an interesting fact: because my house is fairly well insulated and captures a lot of winter sunlight, it acts as a significant buffer against weather changes. I’ve measured that even without a furnace and with no air conditioner, the temperature in here would never go below 40-50F in the winter, or above 86F in summer. In other words, if I were badass enough to put up with the full range of those temperatures, I could run with zero heating and cooling costs indefinitely. 100% of my costs (about $450 per year) are to fine-tune that temperature to allow my family a more luxurious lifestyle.

So as your wimpiness increases, so do your heating and cooling costs. At the extreme end of the spectrum, some people are such heat wimps that they cool their house to the meat-locker temperature of 72F in the heat of summer. You can spend $200 per month keeping a house that cold, even while the house’s natural temperature without cooling might be barely above 80.

Gaining heat acclimation in the summer (and cold acclimation in winter) is about more than just utility bills. It also opens the world back up to you, allowing you to get out and do things that you’d normally wimp out of doing.

A common lament across America these days is this one:

> “I know Mr. Money Mustache taught me I have to get my groceries with a bike trailer, and I’ve been doing it all spring. But now it’s just so hot out there, and he doesn’t know where I live so he won’t see me… so I think I’m just going to sneak out and use my air conditioned car until the hot season ends”.

When Junior Mustaches pull stunts like that, they think they are fooling Mr. Money Mustache, but they are really just fooling themselves. Riding around in your climate-controlled car is just like taking another shot of heroin to prolong a lifetime habit. Instead, you can kick the addiction to comfort, go through the necessary downtime, and be free for life (see: Trainspotting).

So let’s just try this experiment: get yourself out in the heat for at least a few minutes every day. Not just walking to the car, but seriously out in the heat. Go for a walk, try a run if you’re a runner, bike to work, even go out fishing. Drink loads of water (during my fence work I went through about 4 32-ounce jugs of icy water every day). And eat a banana or two to help replace electrolytes lost through sweating.

Instead of increasing your suffering, you’ll actually be building your ability to stop suffering. Take it up to an hour a day. Increase your A/C temperature by one degree every day or two. Watch your need for air conditioning drop drastically. Watch your enjoyment of the outdoors increase. Watch your Money Mustache grow.

A cautionary statement, not that people like MMM readers need these things: heat CAN be dangerous. Your body does need to keep its core temperature within a certain range, otherwise bad things happen. As physical fitness decreases and age increases, so does the risk of overheating. That’s why when record heat waves strike, you always read about a bunch of elderly people kicking the bucket in their non-air-conditioned apartments.

On the other hand, if you carefully and gradually push your comfort boundaries, just as with any form of other exercise or badassity training, you tend to extend those boundaries in a positive way. I try to spend at least an hour a day doing something at least mildly uncomfortable. Just as I once suggested that we should all learn to appreciate mild hunger, it is also nice to appreciate mild discomfort. Without it, you are on the slippery slope to lifetime wimpiness, a place much worse than mild discomfort!

I can see it’s back up in the nineties outside there today. Full sun and no wind. It’s far too comfortable down here in my basement office, so I’m going out for a ride!