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I'm a native of a cold (or maybe I can be generous and say temperate) place, but about a year ago I moved to the tropics to go to graduate school. Coming from a place where there's hardly anyone using a/c, I don't understand what the deal is with A/C here, especially in big buildings like on our campus. Our classrooms are so cold, all the time, even when the weather outside is perfect. Depending on the building we sometimes are able to mess with the thermostat, but we can never actually turn it off, just down, and sometimes it displays some bullshit like that it is set to 77 degrees but reports the current temperature as 65, and is still blowing ice cold air at full power. Talking to my other friends who live in hot places, this appears universal. Inside people's homes they set the a/c reasonably, but any other building will be freezing. I'm writing this now because I'm a member of the graduate student council here and earlier tonight a member was talking about their energy saving plans for the university. It was cold as all get out in the room we were in, despite it being 7pm and already starting to get slightly chilly outside. I raised my hand and asked of reducing A/C was part of anyone's plan to reduce energy. He told me that the campus already HAD put a plan in motion to reduce A/C use a few years ago, that it was in effect right now...as we are all freezing our asses off. We all laughed about the irony of the situation as the girl next to me zipped up her sweatshirt. So anyway, maybe this is a stupid question and someone knows an obvious answer, but what's going on here? Is it some technical thing like, if some rooms of the building aren't massively cold then others will get to hot? Or is it some maintenance thing were running the a/c all the time is actually easier on the machines than turning them off? Or is it some cultural thing? It's been a bother the entire time I've been here, and I know it's not just me, and it's not just people from cold places either. Does anyone know anything? edit: none of the windows are open-able ever either.
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| # ? Mar 16, 2012 06:30 |
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| # ? May 21, 2013 22:00 |
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Samurai Sanders posted:Depending on the building we sometimes are able to mess with the thermostat, but we can never actually turn it off, just down, and sometimes it displays some bullshit like that it is set to 77 degrees but reports the current temperature as 65, and is still blowing ice cold air at full power. Talking to my other friends who live in hot places, this appears universal. Inside people's homes they set the a/c reasonably, but any other building will be freezing. I have no idea why the temperature is set that low though, that's sounds terrible (and terribly wasteful).
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| # ? Mar 16, 2012 07:22 |
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Well I don't have a DIRECT answer but I could brainstorm a lil. You were correct in your assumption that running for a bit longer is better than the compressors turning on and off constantly. Since the temperature is generally higher in the area, the thermostats may not all be controlled from remote locations. In a larger building, they may be linked so that each thermostat has an input, and only when the coldest temp is at the limit it switches the compressors on and off. There's also another issue, which is what's called the "dead band" of the thermostat. If it's set at 77, it's not going to cycle the compressor at 76 and 78. There'll be a deadband of X number of degrees. Could be 2, like the lovely one in my apartment, or it could be 10 cold and 2 hot, or anything like that. Honestly every building generally has something a little bit different than the next. If you can't open the windows you should work out more.
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| # ? Mar 16, 2012 07:23 |
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Odd posted:If you can't open the windows you should work out more. Yeah, the temp is almost certainly set centrally, but I wish I knew why so low. I even asked one of the building maintenance guys once, he didn't know who set the temp and had no idea who did.
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| # ? Mar 16, 2012 07:24 |
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Class rooms are kept cool/cold to keep everybody inside awake.
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| # ? Mar 16, 2012 07:29 |
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Samurai Sanders posted:They're sealed all the way around. Try a hammer. If the maintenance guys don't know, your university might contract their HVAC to an outside company. They'll come around one every few months and change out the air filters and run diagnostics on the big A/C machines on the roofs and such. If you see a van that says "BOB'S HEATING AND COOLING" or something like that, ask one of them guys. If there's a central control, it'll be in a locked utility closet, or physical plant if the building is large enough.
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| # ? Mar 16, 2012 07:29 |
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Illumination posted:Class rooms are kept cool/cold to keep everybody inside awake. It's really part of a bigger issue though. When I go to Tokyo in the summer I see that all the ground-level retail shops have their a/c on and the doors open, wasting untold kilowatts of power every day. After the disaster last year the PM came on and asked home owners to help conserve power by using less a/c in the summer. The online reaction over there was "give us a loving break and go after retailers, they're the ones wasting a/c". edit: the exact words of that representative I mentioned in the OP were something like "*sigh* it's a long story but since the university changed its a/c policy, it's cold as hell MORE EFFICIENTLY than before. That's all I can say for now." We had a dozen more things on the agenda so I couldn't ask him about it any more. Again, growing up in a place that doesn't need A/C, I don't understand, there's some kind of cultural thing going on here that I don't understand. To me, the weather outside is perfect almost all the time, I don't understand why anyone would want to change that when they go inside. Lots of people wear sweatshirts in the building and then take them off when they go outside. It's...perverse.
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| # ? Mar 16, 2012 07:39 |
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My workplace is always cold as hell, and I hate it. I always bring a jacket to work to put on when I get inside. I blame the increasing number of lardasses who come to work in the dead of winter wearing shorts.
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| # ? Mar 16, 2012 07:50 |
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I've always wondered the same thing about why it has to be so drat hot in winter. The temperature in my office hovers around 78 degrees in winter (I brought my own thermometer in to measure). If I close the door it easily gets over 80.
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| # ? Mar 16, 2012 08:47 |
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Another thing you have to consider is that people are walking space heaters. When you get 30-40 people in a room, it can easily heat up faster than the A/C can cool it down. When you remove all those people, the temperature can easily drop 10 degrees. The best solution would probably be to have thermostats hooked up to a mechanism that can impede the airflow into the area. That way, the A/C can continue to run for a while and rooms with few people in them don't start forming ice crystals inside.
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| # ? Mar 16, 2012 09:22 |
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Illumination posted:Class rooms are kept cool/cold to keep everybody inside awake. That makes no sense since coldness induces drowsiness.
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| # ? Mar 16, 2012 13:20 |
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Correct answer is when it comes time to trim the cost of a building proposal HVAC gets cut to the bone. Systems are built as cheaply as possible which limits the quality of the temperature control. They need that money to pay for gold plated toilets in the football teams locker room.
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| # ? Mar 16, 2012 14:18 |
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Trump posted:That makes no sense since coldness induces drowsiness. Yeah when your talking about going into hypothermia. Having worked in schools for a few years now I can promise you that a lot more gets done on a cooler day than a hot day. Most teachers resort to videos on hot days. Onto the AC: 1. The thermostats are hosed, they do break, but people see it set to 21oc and assume that means the room is exactly 21oc. 2. Positioning of the thermostats makes a HUGE difference. If it's located in an area of airflow it will be constantly reading under temperature and trying to make the room warmer. If it's located in sunlight it will be constantly reading over and trying to make the room colder. If it's in a room without any AC (you see this quite a bit) it will try cool the room down, which it can't. Measuring temperature in a larger environment is very hard, and most people will bitch about the AC system when really it's an environmental factor. People sitting under a vent will complain about it being to cold, people sitting near windows bitch about it being to warm, people in the middle bitch about everyone bitching about the AC. 3. It's normally cheaper to keep everything at the same temperature than trying to change it all the time. Walls, especially concrete walls hold a lot of heat. As do carpets, desks, air. The energy required to cool everything down is very big, but to keep it cool is rather small. 4. People and equipment give off a lot of heat. Think about a lecture hall full of people, all using their laptops and the projection equipment spews out heat. That's a whole lot of heat to remove, more heat means more air needs to be chilled. Compounded with the fact that the thermostat is probably broken, set wrong and in a room with no airflow. 5. Acclimatisation. I used to work in an up market gaming centre, we had 3 huge ACs to deal with the massive amount of heat generated by 35 top of the line gaming machines, 4-5 servers, network hardware, 15 xboxs, fridges, and about 60 people. We also had fresh air induction systems to deal with the stink of the customers. On a hot day (45oc) people would come in and find it nice and cool (initial relief),and then too cold(to big a change), after a while they would complain about it getting too warm (getting used to it), go outside for a smoke and then come back in and thank you for fixing the temperature(initial relief). All the while not a single thing had changed.
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| # ? Mar 16, 2012 14:42 |
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Trump posted:That makes no sense since coldness induces drowsiness. If you are dying of hypothermia yes, cool room no. edit: of course.
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| # ? Mar 16, 2012 14:47 |
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oRenj9 posted:The best solution would probably be to have thermostats hooked up to a mechanism that can impede the airflow into the area. That way, the A/C can continue to run for a while and rooms with few people in them don't start forming ice crystals inside. This is how individual offices on a floor work in a building that does not suck, there are dampers that open and close in the vents based on the temp in each room.
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| # ? Mar 16, 2012 15:34 |
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mrmacomouto posted:Yeah when your talking about going into hypothermia. Having worked in schools for a few years now I can promise you that a lot more gets done on a cooler day than a hot day. Most teachers resort to videos on hot days. It's not about the difference between 65F/18C and 95F/35C, it's the difference between 65F/18C and 72F/22C. And it makes no sense to say that there's an advantage at 65F/18C. You'll be distracted by the feeling of cold, type slower and less accurately, and minimise how much you move to reduce the amount of cool air hitting your body (of course we should have a big old study to find the optimal temperature for working environments, it might not be 72F/22C). Women would be more acutely affected in general than men. So I don't think this is the reason, as someone wildly guessed earlier in the thread.
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| # ? Mar 16, 2012 15:47 |
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The Wizard of Oz posted:It's not about the difference between 65F/18C and 95F/35C, it's the difference between 65F/18C and 72F/22C. And it makes no sense to say that there's an advantage at 65F/18C. You'll be distracted by the feeling of cold, type slower and less accurately, and minimise how much you move to reduce the amount of cool air hitting your body (of course we should have a big old study to find the optimal temperature for working environments, it might not be 72F/22C). Women would be more acutely affected in general than men. So I don't think this is the reason, as someone wildly guessed earlier in the thread. It's not that cold temperatures are optimal, it's just that if you've got lovely climate controls it's better to err on the side of too cold. Studies generally show that 21-22 C is ideal, but higher temperatures lead to worse performance than lower ones.
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| # ? Mar 16, 2012 16:22 |
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Ah, so due to technical reasons/cheap equipment it will never be the temperature people actually WANT, so given that it has to be too warm or too cold they chose too cold. I can believe that.
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| # ? Mar 16, 2012 17:13 |
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Samurai Sanders posted:Or is it some cultural thing? People are loving stupid when it comes to heating / cooling, see also for example: instead of warming up their houses at a comfy 20C more or less continuously when it's cold (and only slightly less when you're not home / at night), I know many who drop the day temperature to however low the house will go with the heating completely off, then pump up boiling hot water in the radiators when they get home, resulting in poo poo thermal comfort since everything you touch/sit on is freezing cold (oh god the toilet seat help me), but the air is quickly too warm. It also kills your boiler faster, and is less efficient. I also can't tell you how many thermostat I've seen installed right next to thermostatic mixing valves on a radiator, and when it's too hot people just close the valve... And the thermostat keeps telling the boiler to make hotter water since it can't reach the desired temperature. The thermostatic valve setting on the thermostat, what could it be for ? Edit: I forgot the universal principle of "it will cool down / heat up faster if I turn the dial way beyond the temperature I actually want". Yes but there is an hopefully functional thermostat to sense that and send more cold air... \/\/\/\/\/\/\/\/\/\/
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| # ? Mar 16, 2012 17:52 |
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Pretty much everywhere errs on the side of too cold because people being in the area warm it up just by being there. If you set it too warm, 30+ people in the room will make it even warmer & therefore even more uncomfortable.
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| # ? Mar 16, 2012 17:56 |
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The classrooms in the building I am in most of the time don't have a thermostat, they have a fan control that you can turn up and down (but not off). Interestingly it is sometimes inside of a locked clear plastic box, but we use a toothpick to reach inside and adjust the fan anyway. Whenever we adjust it its always set to max and we're always turning it down and never up, are we somehow wasting energy by doing that? Why wouldn't they want us adjusting it?
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| # ? Mar 16, 2012 18:05 |
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In my experience in Texas, people expect a cold building if it's even a little warm outside; doubly so if it's humid. People will say it's stuffy and complain if the air isn't cool. Ironically, the whiners are often the very same people who eventually put on a sweater. They would rather be able to do that than suffer in a warm building. The other part of it is, once you're used to air conditioning it's very hard to acclimatize fully to the heat outside, or vice versa. This past summer I knew I'd be spending way more time outdoors than usual in what was 100°+ weather, and to help with that, I kept my home temp close to 80 and drove all summer without the AC on in my car. Because I got used to the heat, it didn't bother me nearly as much as it did in the past, and cold buildings were a lot less tolerable. Meanwhile almost everyone I knew was melting and avoiding going outside, and I doubt it was ever cool enough for them indoors.
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| # ? Mar 16, 2012 18:06 |
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Went through this with a building I used to work at and figured out the problem with the hvac there (forced air system with ceiling return). On large buildings, the main thermostat controls the hvac system's output and surprisingly it's quite stable (except for when it started to die, but that's a different issue). The individual room problem was that each thermostat controlled a damper off the main distribution feed to control how much air was sent into the room. A good 50%+ of those damper motors had failed/burned out so the thermostat really did nothing to help out. Since no one bothered to check the motors, people started to move around the venting and completely screwed the proper placement of the in/out vents making it even worse. I think the building is still debating on whether to spend the $100k+ to fix it or not.
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| # ? Mar 16, 2012 19:51 |
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I know in Hong Kong they keep public buildings, restaurants etc near 16-17C which is pretty drat cool inside, to keep humidity down, preventing mold etc.
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| # ? Mar 16, 2012 20:52 |
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unknown posted:Went through this with a building I used to work at and figured out the problem with the hvac there (forced air system with ceiling return). This is more likely to be the issue than some of the other ideas. Many large buildings use what is called a "VAV system". Small areas (like a room or a couple of rooms) will share a "VAV Box" that is basically just a damper. The boxes are served by a central air handler that delivers constant cold air throughout the year (even in winter). Large buildings do not require as much heat, and many of these boxes do not have heat in them (by design). My first guess would be that an actuator or whatever controlling the damper broke and the damper is just fully open(blowing cold air). There are many other possibilities though. If the building has a computerized control system, there are a ton of things related to the system that could be causing the problem (bad programming, communication failure, user error etc). Also, maybe the temperature is ok in the room, but the registers blow air right on the occupants making it feel colder. Check to make sure there is no heat source near the thermostat (if you can find it nearby) that could make it think the room is hotter than it really is. Whatever the system or issue, I don't think anyone is keeping it cold for energy reasons in a tropical environment. The idea that your equipment uses more energy when you turn it off for part of the day is a myth. There is probably some time where it does not make sense, but almost every large building will have times where equipment is scheduled off when the building is unoccupied. It's standard practice because it saves large amounts of energy. Note that it usually doesn't completely shut down, but it will maintain a different temperature setpoint (85F instead of 74F for instance).
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| # ? Mar 16, 2012 22:50 |
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I'm just chiming in to say I have just about never been in the perfect temperature uni room. It is always too cold or too hot. It is never just right.
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| # ? Mar 17, 2012 00:29 |
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ChuckHead posted:If you are dying of hypothermia yes, cool room no. That's not the way it works for me. I can only sleep when it's cold, and when I'm in a cold room I get very sleepy. If it's warm I'm OK. If I start sweating I get restless and can't do poo poo or concentrate on poo poo.
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| # ? Mar 17, 2012 03:29 |
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feld posted:That's not the way it works for me. I can only sleep when it's cold, and when I'm in a cold room I get very sleepy. If it's warm I'm OK. If I start sweating I get restless and can't do poo poo or concentrate on poo poo.
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| # ? Mar 17, 2012 03:36 |
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Yeah this always bugs me during summer in Texas. There seem to be many reasons, but I think it's mostly to prevent molding- which would be much more expensive to repair than the A/C costs. Modern buildings remain relatively closed-off from air flow with the external environment, and because of this humidity builds up inside buildings. Lower temperatures reduce the capacity for air to carry moisture, that moist air is conductive to mold growth and rotting, and therefore you get huge buildings blowing tons of money on their A/C bills. Fans would help, but it's rare to see any large public buildings with fans. But this is why you see the same thing in museums, they typically have strict climate control to be under 73 F or so to prevent rot in the exhibits.
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| # ? Mar 17, 2012 08:37 |
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I live in a hot and humid climate, and I hate how everyone overrelies on the airconditioner. From personal experience, though, I will say that you are almost forced to run it all the time, because even if you don't mind your house being 90 degrees, mold like takes over. Like somebody else said, I'm sure it would be better if we built our houses in a way that naturally circulated better and avoided carpeting, upholstery, etc. That being said, I've also lived in freezing cold climates, and it drives me crazy when you're in eight layers and you have to rip them all off as soon as you walk inside because the heat has been turned up to 80, so I wonder how much of this is just the human condition.
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| # ? Mar 17, 2012 17:11 |
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if you are cold you can put on more clothes. There is only so much someone who is hot can take off. Given that last piece, also factor in body odor from sweating people.
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| # ? Mar 17, 2012 20:22 |
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adorai posted:if you are cold you can put on more clothes. There is only so much someone who is hot can take off. Given that last piece, also factor in body odor from sweating people.
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| # ? Mar 17, 2012 20:37 |
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As someone who designs HVAC systems amongst other things, maybe I should chime in. Around 20% of people will complain that it's too hot/cold regardless. Yes, I specify the controls to be put into the room - but they aren't wired in. It just makes people feel better to crank up the heat when they come in from a cold morning, then turn it down a little after an hour or so. Pure placebo effect - it's all controlled by a BEMS (Building Energy Management System), which is programmed either by the building owner, or in the case of Government buildings, controlled centrally by "Those cunts" who actually have readouts of temperatures etc. on screens in their happy little offices 100 miles away. Common things to do if it's too cold are to find a working thermostat (it won't have an adjustable dial) and hang a damp cloth over it. So the thermostat thinks it's cold, and heats the place up more. The opposite applies if it's too hot - drape it in a hot, damp cloth, it'll think the place is too hot, and cool it down more. That 20% are still going to be unhappy regardless, though...
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| # ? Mar 17, 2012 22:27 |
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There is also the fact that in a humid climate, centralized chilled-water-loop air conditioning is more efficient if set to a lower temperature. The way it works is a multi-step process. First, the incoming air is chilled to the desired dew-point temperature to dehumidify it. Then, the air is re-heated to the desired temperature. The less re-heating you do, the more efficiency there is. What you need to do is ask for more humidity and the temperature will follow.
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| # ? Mar 18, 2012 01:50 |
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In my college dorm room it was 85-90 fahrenheit in the winter sometimes, so I just unscrewed the vent and plugged most of it with cardboard. I tried taping over it with duct tape, but the heat made the tape sticky stuff melt. As an added bonus, the cardboard was pretty much unnoticeable and thus didn't get removed during the periodic maintenance checks. Also, it didn't burn the place down. Sheet metal might have been a better choice for that situation. :P
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| # ? Mar 18, 2012 02:22 |
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OP, where do you live, and also where do you come from?
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| # ? Mar 18, 2012 02:43 |
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Lolcano Eruption posted:OP, where do you live, and also where do you come from?
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| # ? Mar 18, 2012 03:04 |
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mrmacomouto posted:Most teachers resort to videos on hot days. This sounds like a really lovely school.
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| # ? Mar 18, 2012 05:15 |
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See, I can't loving stand the heat, so I am -one hundred percent okay- with overly air conditioned scenarios. Although I would prefer to live someplace that never goes above seventy degrees in the first place. So of course I've spent nearly my whole life in Texas and Arizona.
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| # ? Mar 18, 2012 15:04 |
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| # ? May 21, 2013 22:00 |
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feld posted:That's not the way it works for me. I can only sleep when it's cold, and when I'm in a cold room I get very sleepy. If it's warm I'm OK. If I start sweating I get restless and can't do poo poo or concentrate on poo poo. I'm the opposite! I always get drowsy in warm cars and can't sleep or work when it's too cold because that's all I can focus on. Just yesterday, I was doing an event at the comic store and forgot that it's always cold in there and didn't wear thick enough socks or a warm enough sweater and it was bothering me for the better part of the day. Once my mom came and brought me warm socks and an extra sweater, I was fine. Even up here in Canada, the air conditioning can be a bit too much. I have to bring sweaters everywhere in the summer because malls and movie theaters are bound to be freezing cold.
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| # ? Mar 18, 2012 16:11 |
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