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Post by the light works on Sept 16, 2015 15:34:47 GMT
let's be clear - this isn't a "will my Toyota Prion drown polar bears?" thread. this is a "was dad telling the truth when he said leaving the doors open would heat the outdoors?" thread.
None of it is really empirically testable, but I've always had a bit of curiosity how much our own indoor climate control efforts effect the local conditions. does refrigerating our houses and extracting humidity from the air to dump down the drain make the outdoors warmer and drier in comparison to using swamp coolers to make our indoors more comfortable? does paving half the surface of a town with black asphalt make a difference on summer daytime temperatures? you can see it is untestable because of the magnitude of the scale involved, but theoretically, is it possible that in making indoors more comfortable, we are making outdoors less comfortable in the local area?
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Post by GTCGreg on Sept 16, 2015 16:02:37 GMT
Considering the scale involved, I doubt that cooling or dehumidifying your house has much effect on the immediate outside environment. Of course, someone living next to a power plant may disagree. The paving issue could have an effect. All that black surface area could convert a lot of sunlight to heat. And considering the large areas involved, I could see it increasing outside temperature.
As far as "swamp coolers", I see a problem. These coolers evaporate a LOT of water. The only environment they actually work well in is very hot and dry climates. These are the very locations where there are usually concerns about water shortages.
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Post by the light works on Sept 16, 2015 16:28:25 GMT
Considering the scale involved, I doubt that cooling or dehumidifying your house has much effect on the immediate outside environment. Of course, someone living next to a power plant may disagree. The paving issue could have an effect. All that black surface area could convert a lot of sunlight to heat. And considering the large areas involved, I could see it increasing outside temperature. As far as "swamp coolers", I see a problem. These coolers evaporate a LOT of water. The only environment they actually work well in is very hot and dry climates. These are the very locations where there are usually concerns about water shortages. doing one house won't make much difference, but in a high density area where more than half the square footage of the area is house? and since a swamp cooler's side effect is increasing humidity, wouldn't that serve to both absorb heat and moisten the dry climate? all conjecture, of course. |
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Post by GTCGreg on Sept 16, 2015 17:38:39 GMT
doing one house won't make much difference, but in a high density area where more than half the square footage of the area is house? Crunching a few numbers, let's see where we come out. A cooling system, for typical 2500 sq ft home, dumps about 48,000 BTU of heat into the environment. Out of that, 36,000 is actually cooling the inside of your home. But most of that cooling is leaking back out into the environment through the walls and windows. That's why your A/C has to run almost continuously on a hot day. So the A/C is actually only adding about 12,000 BTU of new heat to the outside environment. Now compare that to what the sun is doing. Bright sunlight give about 4700 BTU of heat per M 2 of area. If you have a 1/4 acre lot, that's about 1000 M 2. Multiply 1000 M 2 by 4700 BTU per M 2 and you get 4.7 million BTU of heat from the sun. Now compare that to the measly 12,000 BTU your A/C system is contributing. Let's look at it another way. If you have a 50 foot long driveway that is 20 feet wide, that's 1000 Sq feet or 93 M 2. If just 1/2 of the sun's energy falling on your driveway is converted to heat, that would be 218,550 BTU of heat just from your driveway. Not sure if my math is entirely correct here, but if it's not, I'm sure the math police will be letting me know. Anyway, I don't see the additional 12,000 BTU your A/C unit is dumping into the environment as having that much effect. |
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Post by the light works on Sept 16, 2015 17:51:43 GMT
doing one house won't make much difference, but in a high density area where more than half the square footage of the area is house? Crunching a few numbers, let's see where we come out. A cooling system, for typical 2500 sq ft home, dumps about 40,000 BTU of heat into the environment. Out of that, 36,000 is actually cooling the inside of your home. But most of that cooling is leaking back out into the environment through the walls and windows. That's why your A/C has to run almost continuously on a hot day. So the A/C is actually only adding about 4,000 BTU of new heat to the outside environment. Now compare that to what the sun is doing. Bright sunlight give about 4700 BTU of heat per M 2 of area. If you have a 1/4 acre lot, that's about 1000 M 2. Multiply 1000 M 2 by 4700 BTU per M 2 and you get 4.7 million BTU of heat from the sun. Now compare that to the measly 4,000 BTU your A/C system is contributing, and you have less than a 0.01% increase in heat caused by your A/C unit. Let's look at it another way. If you have a 50 foot long driveway that is 20 feet wide, that's 1000 Sq feet or 93 M 2. If just 1/2 of the sun's energy falling on your driveway is converted to heat, that would be 218,550 BTU of heat just from your driveway. Not sure if my math is entirely correct here, but if it's not, I'm sure the math police will be letting me know. Anyway, I don't see the additional 4000 BTU your A/C unit is dumping into the environment as having that much effect. I am certainly not a math whiz, so I'm not going to challenge your numbers. but the AC is also condensing moisture out of the air which is essentially skipping the raining step of the water cycle. most AC units I know of release the water into the ground, so it might be no net difference, but it might reduce precipitation in an area. part of my curiosity is whether we are engaging in a self-defeating cycle, where we are contributing to the very conditions we are trying to remedy. I know one of the benefits of watering my garden in the evening has been having a cool breeze coming into the windows at the back of the house - it almost compensates for the warm air released by the dehumidifiers Mrs TLW runs even though the windows are all open. |
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Post by GTCGreg on Sept 16, 2015 18:02:12 GMT
In a humid environment, a central A/C may remove about 5 to 10 gallons of water per day. About the same a flushing your toilet a few extra times. And, like you say, the water is usually just dumped back outside, the net change is zero. Even if the water is dumped into the sewer system, we're not really talking about that much water.
I do think the pavement thing could be an issue though. Back in the 60's, they moved the official Chicago weather reporting station from Midway Airport, which was in the heart of the city, to O'Hare airport which, at the time, was surrounded by nothing but farm land. Even though the airports were only about 15 miles apart, the average temperature for Chicago dropped about 3 degrees. As the area around O'Hare built up, so did the average temperature. It's now back to where it was when the station was at Midway. And, no, it's not global warming. It's regional paving.
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Post by the light works on Sept 16, 2015 18:39:11 GMT
In a humid environment, a central A/C may remove about 5 to 10 gallons of water per day. About the same a flushing your toilet a few extra times. And, like you say, the water is usually just dumped back outside, the net change is zero. Even if the water is dumped into the sewer system, we're not really talking about that much water. I do think the pavement thing could be an issue though. Back in the 60's, they moved the official Chicago weather reporting station from Midway Airport, which was in the heart of the city, to O'Hare airport which, at the time, was surrounded by nothing but farm land. Even though the airports were only about 15 miles apart, the average temperature for Chicago dropped about 3 degrees. As the area around O'Hare built up, so did the average temperature. It's now back to where it was when the station was at Midway. And, no, it's not global warming. It's regional paving. but flushing your toilet takes the water from a surface or aquifer supply whereas the AC removes it from the atmosphere. |
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Post by OziRiS on Sept 16, 2015 19:25:50 GMT
Let's look at it another way. If you have a 50 foot long driveway that is 20 feet wide, that's 1000 Sq feet or 93 M 2. If just 1/2 of the sun's energy falling on your driveway is converted to heat, that would be 218,550 BTU of heat just from your driveway. Is it me, or does that calculation (assuming it's correct - and I'm not math geek enough to tell if it is) lend credence to the asphalt thing? Most driveways aren't even paved with asphalt but with some sort of stone, so how much heat would that same driveway reflect if it was all black? And how does that translate to the huge amounts of asphalt used all over the world? This might actually be an important question to answer. I wonder if anyone else has ever thought of it...? |
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Post by GTCGreg on Sept 16, 2015 19:31:46 GMT
In a humid environment, a central A/C may remove about 5 to 10 gallons of water per day. About the same a flushing your toilet a few extra times. And, like you say, the water is usually just dumped back outside, the net change is zero. Even if the water is dumped into the sewer system, we're not really talking about that much water. I do think the pavement thing could be an issue though. Back in the 60's, they moved the official Chicago weather reporting station from Midway Airport, which was in the heart of the city, to O'Hare airport which, at the time, was surrounded by nothing but farm land. Even though the airports were only about 15 miles apart, the average temperature for Chicago dropped about 3 degrees. As the area around O'Hare built up, so did the average temperature. It's now back to where it was when the station was at Midway. And, no, it's not global warming. It's regional paving. but flushing your toilet takes the water from a surface or aquifer supply whereas the AC removes it from the atmosphere. And you have to wonder how much a swimming pool affects it. I have a 18X35 foot pool. On a hot day, it can lose up to an inch of water. The last time I calculated it out, I believe that was about 300 gallons. So on a hot day, my pool puts more moisture into the environment than about 50 of my neighbors A/C units remove. And again, that's assuming the A/C units are flushing the water down the drain. Most don't. I know mine doesn't. The A/C unit drains into the basement sump which then pumps it out into the yard when the sump gets full. There, the water evaporates back into the air, reenters the house, gets removed by the A/C., gets pumped out to the yard, and the cycle repeats. Now were A/C units may affect the environment is around power plants. Each A/C unit contributes a 3 to 5 kW load on the plant. Depending on what's fueling the power plant, I'm sure that will have some effect on the environment. |
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Post by the light works on Sept 16, 2015 19:52:44 GMT
but flushing your toilet takes the water from a surface or aquifer supply whereas the AC removes it from the atmosphere. And you have to wonder how much a swimming pool affects it. I have a 18X35 foot pool. On a hot day, it can lose up to an inch of water. The last time I calculated it out, I believe that was about 300 gallons. So on a hot day, my pool puts more moisture into the environment than about 50 of my neighbors A/C units remove. And again, that's assuming the A/C units are flushing the water down the drain. Most don't. I know mine doesn't. The A/C unit drains into the basement sump which then pumps it out into the yard when the sump gets full. There, the water evaporates back into the air, reenters the house, gets removed by the A/C., gets pumped out to the yard, and the cycle repeats. Now were A/C units may affect the environment is around power plants. Each A/C unit contributes a 3 to 5 kW load on the plant. Depending on what's fueling the power plant, I'm sure that will have some effect on the environment. I wonder if anyone formal and official has promoted the theory that the fountains in Rome also served as a form of air conditioning, as well as a (relatively) clean reliable water source. you don't truly appreciate evaporative cooling until you have been downwind of a dam with an open spillway on a hot day. |
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Post by GTCGreg on Sept 16, 2015 20:06:24 GMT
I wonder if anyone formal and official has promoted the theory that the fountains in Rome also served as a form of air conditioning, as well as a (relatively) clean reliable water source. you don't truly appreciate evaporative cooling until you have been downwind of a dam with an open spillway on a hot day. And hence the popularity of those "mister" stations at amusement parks. That is, if you have a good water supply. I doubt they're used that much in California anymore. |
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Post by the light works on Sept 16, 2015 20:09:47 GMT
I wonder if anyone formal and official has promoted the theory that the fountains in Rome also served as a form of air conditioning, as well as a (relatively) clean reliable water source. you don't truly appreciate evaporative cooling until you have been downwind of a dam with an open spillway on a hot day. And hence the popularity of those "mister" stations at amusement parks. That is, if you have a good water supply. I doubt they're used that much in California anymore. not at the momnet, though I understand they are relatively thrifty with water. |
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Post by silverdragon on Sept 17, 2015 7:33:40 GMT
The weather reports alone are evidence, frost reports "at night" will state minus 2 in rural areas, maybe just about zero in towns and cities, or just above zero. "Some say" that we built the towns and cities in warmer areas anyway.... Thats bunkum. Proof would be those bloody patio heaters... why people have them is beyond me. Anyway, further proof is the concept that the exhaust fumes, all that hot air, just disappears.... Of COURSE exhaust fumes have a significant warming effect in high density areas. Has anoune here ever had a thermal camera?.. and taken a look at windows?... You can spot Double glazing/Triple glazing a mile away just by the heat signature, where triple glazing os often better insulation that the surrounding wall, unless that house has gone all super insulated. [Remembering that that camera is a visual representation in colour of heat, and you can set the sensitivity that high that even a small .5degC can produce huge colour changes.] But we do waste a LOT of heat... But then take that camera to say an active volcano. It will blind you. Here is a NOT active volcano....  Thermal imaging of a heard of cows?... more than your average house. Horse?...  At this moment in time, El Ninio is massing with the earth's weather systems. Its a once-every-so-many-years phenomenon, but that alone is creating more heat mass on the west side of America that the whole of America's human population, from what I can find. Do we influence the weather?... Hell yeah. But forest fires occurring naturally do as well. And as some forest plants ONLY flourish after a forest fire, and lay dormant in between, we can only presume this is natural anyway. I have yet to see concrete evidence that humanity alone is solely responsible for the weather.... And then there is the night side. On the night side of the planet, heat escapes to space. MORE heat, More escapes...... We are sitting on a planet that has a MOLTEN core, somehow, I know the earth breathes, but I think it is well used to looking after its self?... Can we do more to minimalise our footprint?.. Yes. Of course we can. |
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Post by GTCGreg on Sept 17, 2015 9:16:53 GMT
while I agree with most of your views, I believe TLW was speaking more on a local level.
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Post by the light works on Sept 17, 2015 14:07:30 GMT
right: sort of a "take two exactly identical towns on two parallel worlds, use heat pumps to heat an cool one, and use gas furnaces and swamp coolers to heat and cool the other and see what the difference in local weather is in a few years" thing.
does what we do have a cumulative effect on our global climate? yes. should we live in caves and subsist on roots and berries because of it? no. should we at least not be stupidly wasteful? absolutely. stupidly wasteful is a bad thing. but this question is whether every kid in town leaving the door open will make a difference in the outdoor temperature.
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Post by GTCGreg on Sept 17, 2015 15:10:52 GMT
Well if you had asked my dad, the answer would've been a resounding yes. He was so repetitive that our bird, which was not a known speaking variety, would say "close the door" every time someone left the house.
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Post by the light works on Sept 17, 2015 15:37:36 GMT
Well if you had asked my dad, the answer would've been a resounding yes. He was so repetitive that our bird, which was not a known speaking variety, would say "close the door" every time someone left the house. I think the point that I turned off the breakers on the heaters was the point that I walked into the kitchen and found the windows open and the thermostat set to 80. the only heater that is still turned on is in the laundry/bird room, and that is set at 60, with a pin to keep it from being turned up. |
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Post by GTCGreg on Sept 17, 2015 15:41:46 GMT
Well if you had asked my dad, the answer would've been a resounding yes. He was so repetitive that our bird, which was not a known speaking variety, would say "close the door" every time someone left the house. I think the point that I turned off the breakers on the heaters was the point that I walked into the kitchen and found the windows open and the thermostat set to 80. the only heater that is still turned on is in the laundry/bird room, and that is set at 60, with a pin to keep it from being turned up. Maybe you need bird proof locking thermostat covers. (works for wives too) |
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Post by the light works on Sept 17, 2015 15:43:48 GMT
I think the point that I turned off the breakers on the heaters was the point that I walked into the kitchen and found the windows open and the thermostat set to 80. the only heater that is still turned on is in the laundry/bird room, and that is set at 60, with a pin to keep it from being turned up. Maybe you need bird proof locking thermostat covers. (works for wives too) I need powered self closing windows. my brother's beach house does not have thermostats. the central computer decides when to turn the heat on and off based on thermocouples inside secure boxes in the walls. |
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Post by GTCGreg on Sept 17, 2015 15:47:08 GMT
Maybe you need bird proof locking thermostat covers. (works for wives too) I need powered self closing windows. my brother's beach house does not have thermostats. the central computer decides when to turn the heat on and off based on thermocouples inside secure boxes in the walls. And I'm sure it's very comfortable... Inside the walls. |
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