# A/C unit running 24/7 .. 365 days a year... in the Midwest! why?? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [November 28, 2011, 7:52am UTC](https://boards.straightdope.com/t/a-c-unit-running-24-7-365-days-a-year-in-the-midwest-why/604324 "2011-11-28T07:52:06Z")\ **Posts on this page:** 10\ **Page:** 2
**Author:** ![Wile\_E](https://avatars.discourse-cdn.com/v4/letter/w/c37758/32.png) [@Wile\_E](https://boards.straightdope.com/u/Wile_E)\ **Post date:** [November 28, 2011, 5:59pm UTC](https://boards.straightdope.com/t/a-c-unit-running-24-7-365-days-a-year-in-the-midwest-why/604324/21 "2011-11-28T17:59:16Z")
I think the important question is … What is the brand of the A/C that can run 24/7 for five years? ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [November 28, 2011, 6:17pm UTC](https://boards.straightdope.com/t/a-c-unit-running-24-7-365-days-a-year-in-the-midwest-why/604324/22 "2011-11-28T18:17:40Z")
> [@Wile\_E](#): > > I think the important question is … > > What is the brand of the A/C that can run 24/7 for five years? If it’s on all the time, then it would stay a more constant temperature than if it cycled on and off. It might be better for the unit that way. ---
**Author:** ![Skywatcher](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/skywatcher/32/254_2.png) [@Skywatcher](https://boards.straightdope.com/u/Skywatcher)\ **Post date:** [November 28, 2011, 6:29pm UTC](https://boards.straightdope.com/t/a-c-unit-running-24-7-365-days-a-year-in-the-midwest-why/604324/23 "2011-11-28T18:29:40Z")
> [@TruCelt](#): > > Huge windows can produce a lot of passive heat. Also, I read about an apartment that literally baked (plastic dishes melting, etc.) after a building across the street installed a reflective faux front that sent tons of sunlight through the windows. I want to say it was a Gehry building? > > ETA: found it [Walt Disney Concert Hall - Wikipedia](http://en.wikipedia.org/wiki/Walt_Disney_Concert_Hall) althought the dish story seems to have been hyperbolic. Or [conflated with a similar story in Vegas](http://www.kypost.com/dpps/news/local_news/water_cooler/vegas-hotel-has-melting-%27death-ray%27_5176983). ---
**Author:** ![Munch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/munch/32/5281_2.png) [@Munch](https://boards.straightdope.com/u/Munch)\ **Post date:** [November 28, 2011, 6:55pm UTC](https://boards.straightdope.com/t/a-c-unit-running-24-7-365-days-a-year-in-the-midwest-why/604324/24 "2011-11-28T18:55:54Z")
> [@carnivorousplant](#): > > Perhaps it is a heat pump. This is my guess as well. ---
**Author:** ![Mtgman](https://avatars.discourse-cdn.com/v4/letter/m/b5a626/32.png) [@Mtgman](https://boards.straightdope.com/u/Mtgman)\ **Post date:** [November 29, 2011, 5:10pm UTC](https://boards.straightdope.com/t/a-c-unit-running-24-7-365-days-a-year-in-the-midwest-why/604324/25 "2011-11-29T17:10:46Z")
[Confirmation Bias](http://en.wikipedia.org/wiki/Confirmation_bias)? What data do you have to support the 24/7/365 assertion? Surely you haven’t spent the past five years, at least, watching this unit run? Every time you’ve passed it, which would be a very small subset of the full past five years, it’s been running. Or at least every time you’ve noticed it when you passed it? Maybe you haven’t noticed it when it wasn’t running. Maybe you saw it on a handful of days when it was running when you didn’t expect it and started thinking of it as “that AC that’s always on” so every time you notice it running you mentally fill in the blanks for all the rest of the time, even when you didn’t see it. This is really a very common attribute of human beings. We love things to be predictable and fit into pretty patterns. [Slate did a whole series on how memory can be manipulated or otherwise falliable](http://www.slate.com/articles/health_and_science/the_memory_doctor.html) and it produced some very damning results for human memory, The main thing we take for granted as reliable. This excerpt is from [Leading the Witness](http://www.slate.com/articles/health_and_science/the_memory_doctor/2010/05/leading_the_witness.single.html), one of the articles in the series. > [@](#): > > For example, when eyewitnesses were shown lineups of possible culprits, they sometimes selected a face that was familiar for a different reason. Loftus demonstrated this by showing experimental subjects six photos while they listened to a crime story. One photo depicted the culprit; the others depicted innocent characters in the story. Three days later, she showed the same subjects a photo of one of the innocent characters along with three photos of other people. From these four pictures, she asked them to pick the criminal. Twenty-four percent of the subjects correctly refused to pick a photo. Sixteen percent picked one of the three new photos. Sixty percent picked the photo of the innocent character. They remembered it from the crime story but confused it with the perpetrator. > > Police lineups worsened this confusion. In another experiment, after watching a mock crime, subjects were offered a lineup that didn’t include the perpetrator. One-third of them picked somebody anyway. But when the cops conveyed extra confidence—“We have the culprit and he’s in the lineup”—78 percent of the subjects picked somebody My guess is the AC unit hasn’t been running 24/7/365, it just seems like it. The main noise we notice from an AC is the compressor. The fan really isn’t very loud. If the compressor, more specifically the suction line, is exposed to the elements and it gets below about 40 degrees Fahrenheit outside, then the freon would condense inside the suction line, before it gets to the compressor. Then the compressor would try to compress liquid freon, which doesn’t compress as much as gaseous freon. In the real world when this happens it causes the compressor to burn out and the unit would be dead. If there have been sub 40 degree Fahrenheit temps in the past five years, and the AC isn’t dead, then it’s almost a sure thing that the compressor wasn’t running during that time. Maybe take a piece of paper with you whenever you’re walking by the unit in the future with a column for on and off and tick off both states to see if you’re misremembering the frequency of the unit running. Also make a point of going by there on a sub 40 degree day. Enjoy, Steven ---
**Author:** ![gaffa](https://avatars.discourse-cdn.com/v4/letter/g/e68b1a/32.png) [@gaffa](https://boards.straightdope.com/u/gaffa)\ **Post date:** [November 30, 2011, 4:16am UTC](https://boards.straightdope.com/t/a-c-unit-running-24-7-365-days-a-year-in-the-midwest-why/604324/26 "2011-11-30T04:16:27Z")
> [@carnivorousplant](#): > > Perhaps it is a heat pump. Exactly. The “Air Conditioner” in the yard of my apartment here in Kansas City is running right now, and will continue until it drops below freezing. I worked at a video editing facility where we had to have air conditioning year round to cool the racks of equipment. We couldn’t just let in outside air because it was too moist. ---
**Author:** ![diggerwam](https://avatars.discourse-cdn.com/v4/letter/d/919ad9/32.png) [@diggerwam](https://boards.straightdope.com/u/diggerwam)\ **Post date:** [November 30, 2011, 12:31pm UTC](https://boards.straightdope.com/t/a-c-unit-running-24-7-365-days-a-year-in-the-midwest-why/604324/27 "2011-11-30T12:31:26Z")
My mother had COPD and really couldn’t stand untreated air, too humid, too warm. Maybe the person in that room has some sort of breathing illness. ---
**Author:** ![EvilTOJ](https://avatars.discourse-cdn.com/v4/letter/e/ee59a6/32.png) [@EvilTOJ](https://boards.straightdope.com/u/EvilTOJ)\ **Post date:** [November 30, 2011, 1:11pm UTC](https://boards.straightdope.com/t/a-c-unit-running-24-7-365-days-a-year-in-the-midwest-why/604324/28 "2011-11-30T13:11:04Z")
> [@friedo](#): > > Low-rent server farm? Sort of. Obviously he’s a [hardcore WoW player](http://nbnl.globalwhelming.com/wp-content/uploads/2008/10/prepared.jpg). I read somewhere a regular PC puts out the same amount of heat as a human, so if there’s even half a dozen PCs in one room it’ll make it really warm. In the winter I bet just the fan portion is running. ---
**Author:** ![mack](https://avatars.discourse-cdn.com/v4/letter/m/b19c9b/32.png) [@mack](https://boards.straightdope.com/u/mack)\ **Post date:** [December 22, 2011, 6:30pm UTC](https://boards.straightdope.com/t/a-c-unit-running-24-7-365-days-a-year-in-the-midwest-why/604324/29 "2011-12-22T18:30:11Z")
We live in NYC in a ground floor apartment over the building’s boilers. We run the window unit a/c year-round. ---
**Author:** ![kyrio](https://avatars.discourse-cdn.com/v4/letter/k/e9bcb4/32.png) [@kyrio](https://boards.straightdope.com/u/kyrio)\ **Post date:** [December 22, 2011, 6:55pm UTC](https://boards.straightdope.com/t/a-c-unit-running-24-7-365-days-a-year-in-the-midwest-why/604324/30 "2011-12-22T18:55:33Z")
I had to have my A/C on all year round because it was hot in the summer and boiling in the winter. You can’t have granny feeling chill and there was no per unit control of the heat. [Previous page](https://boards.straightdope.com/t/a-c-unit-running-24-7-365-days-a-year-in-the-midwest-why/604324.md?page=1)