AC Apocalypse. Whatcha gonna do?

20+ year old a/c unit, 90-100º forecast for days… need I say what happened over the weekend? I’ve been around for a while, namely since before a/c was common. Boy, how quickly we forget how pampered is our rich-world life.

On a related note, I saw Texas Reliability forecast blackouts down there and urged folks to turn off the AC, riiight.

So just a thread to think about heat related actions if not preps. According to Wiki in most years, more people succumb to excessive heat than any other weather related cause. Obviously GW is causing anomalous heat waves (like in the PNW last year) and especially prolonged heat events are dangerous because warm nights prevent the cooling respite more fragile bodies need.

Just a few random things:

If you are in a dry climate, evaporating water, however you can get that to happen, is the natural solution. Water changing from liquid to vapor absorbs heat, cooling it’s surrounding. But in humid climes you need other plans. We live in Missouri now, dry in the winter and wet—er in the summer. Here a summer breeze is as likely as not to be so saturated that not only is your efforts to evaporate water for cooling inefficient but your own perspiration is much less effective. Be especially cautious when the dew point is high, 65º ot higher because your natural cooling is less effective.

Warmer air holds more water, to a point. The dew point is the temperature at which the air is saturated, below that temperature the moisture in the air condenses—forms dew. Think of a cold drink glass with beads of water on the outside, the glass is colder than the dew point so moisture from the air condenses on it. But on the flip side, with a high dew point the air is already near-saturation and perspiration or a wet kerchief is less effective as cooling because water won’t evaporate into near-saturated air so won’t absorb heat in changing phase.

So, getting out of those weeds, we live in an old house 150 years maybe. Old houses had lots of cooling strategies we can implement in an emergency. Our house s 12′ ceilings and windows that go up almost to 10′. Open down the top sash and open up the bottom at night and automatically a convection current sweeps out the hot air at the top, pulling in cool air at the bottom—even with no breeze. That is if the air cools off at night. The US SE may not be uninhabitable in a warmed future because humidity holds heat, preventing night time cooling. 

Houses once employed breezeways to, you know, catch the prevailing breeze. Also they did pay attention ot orientation. Here in SW MO the prevailing wind is from the NW in winter but the summer breeze usually comes from West or SW. So the old houses keep their backs to the NW and their sitting porch to the SW—to catch the summer breeze and shade the summer evening sun that is WNW about now. 

Of course you can’t reorient your house in an A/C apocalypse but you can think about those natural angles. Say leaving the drapes closed on the East in the morning and west/north in the afternoon. In the evening, open the windows and go outside as soon as outside is cooler, the SE side will have been in the shade longest at 9P so will be coolest, everything else equal.

Anyway long enough rant for now. I fixed the AC so gotta go enjoy it. What strategies do you have for dealing with AC Apocalypse? 


  • Comments (16)

    • 3


      Thanks for the reminders. I grew up in Pennsylvania without AC many moons ago. It’s not as pleasant as AC but I wasn’t traumatized by it either. If it’s what you know you adjust and live with it until the fall season.

      Our old house had a covered porch – 2 bedrooms were right above – and the porch floor was smooth concrete 4′ thick. Trees completely shaded it too. That concrete was cool anytime in the summer. It felt great barefooted. It was screened in summer and had 4’x6′ window frames in the winter. My parents loved it after dinner with a small fan on low.

      I don’t have that now and the heat affects my wife more now so our ‘Plan B’ will be to go to the basement if AC goes out for long.

      Power went off Saturday for about 90 minutes throughout town and we filled a few insulated 32 oz. cups with ice and water. If it went much longer we were going to take cool showers and put on looser clothing.

    • 1

      Popsicles or other frozen desserts are my go to way of staying cool. Cool yourself down from the inside out. 

      Putting my head under the cold water of a faucet or shower is also nice as it evaporates from my hair.

    • 2

      Our house is old but was never really designed as a home, where we live is up in the hills where it gets hot in the summer but very cold in the winter. to get around its overheating during the summer we fitted porches along the South facing elevation to shade the windows which reduced passive gain when the sun is high and some velux windows in the attic roofs to increase ventilation. We have also insulated the place as much as we can.

      Wales doesn’t have the extremes of temperature that you guys describe but with global warming it is likely that we will see more extremes.

      • 1

        Or much colder if the Atlantic current collapses? May have to tear down the porch roofs and burn em.

        Here’s hoping not!

    • 2

      One strategy is to have plenty of mosquito netting.  With the AC out, one has to open up the house to the outside, to get airflow & cooler evening breezes.  Living in Mississippi, I keep lots of netting and mosquito spray… just in case.

      My house has 3 central air units, so as long as we have power, I can stay cool.  But in a power out situation, one has to adapt.  It helps that I spend so much time out in our extreme heat.  

      • 1

        Very good! A sleeping porch too.

      • 2

        Yes, in the old days in the south, folks slept on their porches at night.  Most homes back then had wrap around porches with many screened to keep the bugs out.  Our back porch is screened but the big porches out front aren’t.  Thus the possible need for mosquito netting.

    • 2

      Here’s a new product that was shared with us from another user. It’s a wearable portable AC unit that you place on your back underneath your shirt. If it does work well, this could easily be powered by a small portable solar panel after a power outage rather than the energy hog that a full house AC unit would be and require a large gasoline powered generator.

      Sony Releases Wearable Air Conditioners To Keep You Cool for Hours on the Go

    • 4

      We keep a spare capacitor for the AC in our pantry. Our neighborhood experiences power surges fairly regularly, and those will blow out the capacitor. This year it happened on July 2, when temps were over 100 and everyone was closed for the holiday. Took my husband 20 minutes to replace the capacitor and get the AC back up and running.

      This is probably the 3rd or 4th time it’s happened in 5-10 years. Capacitors are cheap, and the electrical connections straightforward.

      • 2

        Now that is being prepared! Knowing the part most likely to fail and having backups on hand for when they do.

      • 3

        Couldn’t agree more! Both of the A/C outages I’ve had in the last 6 years (including last week) were simply due to the starter capacitor dying in the outside fan unit. Just as Nuqneh said, it requires only hand tools & 20 minutes to replace the capacitor. Having the $35 part on hand saved a $300 service call. If you’re modestly handy, you can make the repair.

      • 2

        Correct me if I’m wrong, but a capacitor stores power and retains that voltage when the unit is turned off.  If you don’t know what you are doing, a charged capacitor can deliver a shock, even when the unit you are working on has been isolated from its power source.

        I’m no electrician but that is what I’ve been told.

      • 1

        That’s my understanding as well Redneck. 

        Some components devices can carry lethal doses of electricity and you have to be careful when disassembling. A microwave oven can be turned into a DIY welder, but it can also kill you if you don’t modify it correctly.

      • 2

        Yes. A capacitor is like a battery that discharges super fast, that’s how it kick-starts a motor, drives a sub-woofer, etc. Not only can they hurt you if you accidentally short them even after power has been disconnected, they can do damage to equipment when re-connecting power to a discharged capacitor, because they charge as fast as they discharge.

        For example, when connecting a battery bank to a large inverter that has large capacitors (there to power surge demands) you can do real damage to your equipment from arcing if you aren’t careful.

        The way to be careful is to put some kind of resistance between the capacitor and the power source to charge or between the poles of the capacitor to discharge rather than just shorting the poles or connecting the cables.

        Use a small resistor, or a light bulb, I saw a vid where a guy used a pencil lead—because those things provide resistance that slows down the flow so nothing (including you) is damaged.

        Here’s a vid

      • 2

        Redneck, you are correct and some simple safety precautions are in order:

        You MUST first turn off the power to the AC unit (I’m talking about the big outside compressor unit) before changing the capacitor. In the US, there is commonly an electrical disconnect box specifically for the AC unit that is located on the house wall next to the unit. Inside this box is a blade-type fuse which simply pulls straight out. Pulling this fuse will disconnect the unit from power.

        If you can’t disconnect the power to the AC unit, don’t attempt anything else. Stop and call a service person.

        With the power disconnected, you can verify the capacitor is discharged by checking for voltage across the terminals using a multimeter. A dead capacitor will have little or no voltage on it.

    • 3

      On the capacitor front, I did check mine and it was weak according to my fancy milli-farad meter. However, after replacing the cap, turned out that wasn’t the problem. It was an internal problem in the t-stat that sent enough of a signal to show on the meter but not to fire the condenser. Took a tech almost two hours to figure it out after I gave up. It is something I’ll check next time but I’m sure there are a multitude of similar little gotchas.

      Oh, and I do have a spare cap now, LOL

    • 1

      AC? What’s that?

      I kid, but I live in old adobe so it’s one of the modern amenities I live without, along with a microwave, bed and automatic ice maker.

      Normally keeping the house cool involves keeping all the windows closed but the mother, as always cannot handle keeping the windows closed because “the air isn’t moving”.

      So it’s usually hot,, but a nice passive heat reduction is that IR and heat blocking film you can stick or soap seal to the windows.

      In another forum post about the heat, I mentioned the sniper veil, a coarse cotton mesh that cools extremely well in dryer conditions.

      Cooling centers while wearing n95 or p100 respirators would probably be a reasonable last ditch, but damn.

      Maybe keeping a cheap or empty Styrofoam cooler specially for small snacks and daily drinking water so it actually stays cool when the heat is up would be helpful, even in Nalgenes my water can be lukewarm in hot weather even if it’s sitting right next to me. Grab a bag of ice from the gas station if the power goes out and toss it in there and it’ll keep water icey without having to let the cold out of the fridge.maybe a few plastic covered ice cream snacks too to keep up the energy.

      Otherwise I personally enjoy the modern convenience of lithium rechargeable batteries. Multiple battery packs for my phone with wireless, one for lights and small size rechargeable batteries. And the other for recharging the rechargeable fans over night and during use. Solar panels are a given.

      I was considering this fan for pulling air in at night. 

      I think it would work but I’m not sure because it’s a bit steep for my budget.

      My mom and I both have 8 inch fans from Opolar, hers ossilates, has a timer and has a removable battery pack. Mine is on its second summer and it runs almost constantly,I run it at night over my legs cuz where I sleep has zero air movement, and during the day. It runs while charging so I run it off battery during the day and charge at night, conceptually when the power is less likely to go out, so it’ll be full the next day if the power goes out.Quiet and effective.

      Plus dollar store hand fans, they work great after you glue the fabric back on.

      We also have tape on the side of the fridge prepped to tape it closed so we don’t open it when the power is out. It saved us the last time making dinner when the power went out.

      I need to get some wireless fridge thermometers, there’s some relatively cheap that seem to be a good balance, and run a long time on accessible batteries.

      There was another forum post about it, but staying used to the heat is also important