A thread about saving the planet, in Off Topic and not Urban Planning because it has nothing to do with roads.
When I lived at my previous house, the central air conditioning didn't work (it did when the house was built but stopped), so we had a room air conditioner. It worked mostly fine. While not optimal for comfort, it was decent enough, and it reduced electricity usage during summer months by about 30%. The two following conditions are necessary for this tradeoff to be worth it:
1. It must be in a climate where such is doable. I live in northeastern Massachusetts; other places where it can be done include New York City, Chicago, and places in between, plus Seattle and Portland. It is essential that nighttime temperatures are below 70°F.
2. Certain rooms must be used more than others, since room conditioners don't work on the whole house that well. If it's a family of six people each with their own room, plus a shared living room with a TV/gaming console, it won't work well.
Side note 1: When it did reach 97°F or so, the house did not feel hot the first day. It was only when there were two hot days in a row that I started to feel mildly uncomfortable. The area I live in is always tolerable outdoors after 9 PM or so; if you remember the heat wave in Washington that killed people a few years ago, the issue wasn't the daytime heat but rather that it didn't get cool enough at night, which meant that the indoor heat kept building up.
Side note 2: Europe doesn't have that much air conditioning, and they seem to do fine.
As an estimate: 30% savings × 1/4 of the population × 1/3 of the year × 21% of overall electricity used by homes = 0.5%, maybe 0.6-0.7% if you consider that less energy is currently used in months where the weather is already good. Less than 1% seems low, but it can be doubled or tripled if people farther south voluntarily choose not to use central air conditioning when the temperatures are in the 80s and switch to central when it gets hotter than that.
I used as much as 900 KW of monthly energy in a home with just 2 air conditioners.
In my current house with central air, I've never exceeded 750 KW.
These homes are nearly identical (1600-ish sq feet, two floors, 3 bedrooms).
Your mileage may vary, buy my data point is that central air uses less, not more.
I just looked it up, and it appears that you're right. Now that I think about it, the 30% was compared to the average home, not compared to what it previously was. My home was pretty small, which would explain the difference.
In wattage I don't know off the top of my head but it did save us about $300 dollars a month during the summer last year when the coolant line needed to be replaced. Problem was it was consistently 92-95F in the house when sundown hit. Granted that's Fresno and an extreme example given we got close to 110F a bunch of times last year.
Quote from: 1 on May 03, 2022, 08:48:27 AM
Side note 2: Europe doesn't have that much air conditioning, and they seem to do fine.
Maybe they're not reporting European heat related deaths on your local news in the states, but when you narrow down the search, they're not doing fine...
https://www.google.com/amp/s/www.bbc.com/news/world-europe-49628275.amp
https://www.google.com/amp/s/english.elpais.com/science-tech/2021-07-28/the-spanish-heat-paradox-temperatures-soar-but-related-deaths-drop.html%3foutputType=amp
In the US there tends to be a lot of reporting by state, not by country, but comparably speaking we're on par if not better than European countries when it comes to heat-relates deaths.
I think the better question might be "how much energy could be saved if every single HVAC unit was properly tuned and maintained," since eliminating central AC wouldn't be too terribly popular.
And my own anecdotal evidence seems to indicate that central AC is more efficient than a series of window units.
I don't have proof of this, but just an uneducated guess: you can configure your central a/c so the fan runs constantly whether or not the outdoor unit is running, which (to me) would seem to help, by keeping the air moving around, thus causing the outdoor unit to run less..
maybe?
of course, I live in colorado, and in the mountains to boot, so nighttime lows here are usually 55-65. A swamp cooler does me fine.
Quote from: zachary_amaryllis on May 03, 2022, 10:42:42 AMI don't have proof of this, but just an uneducated guess: you can configure your central a/c so the fan runs constantly whether or not the outdoor unit is running, which (to me) would seem to help, by keeping the air moving around, thus causing the outdoor unit to run less..
It should definitely be doing that anyway if you have a smart thermostat, not sure if it also does that if you have a "dumb" thermostat.
I live in Palm Springs. Central AC is pretty much a necessity. That said, I rarely use my AC except between July 4 and Labor Day. I also have an evaporative cooler, aka swamp cooler. They work great when the air is extremely dry like here in the desert. Many snowbirds only have swamp coolers. I've probably saved a few thousand since I installed mine four years ago.
I find these comments about "necessity" a bit amusing, having spent so much time in the desert climate of northern Mexico–where the large majority of houses have neither heat nor a/c.
I was today years old when I learned that swamp coolers exist.
Quote from: kphoger on May 03, 2022, 04:25:49 PM
I find these comments about "necessity" a bit amusing, having spent so much time in the desert climate of northern Mexico–where the large majority of houses have neither heat nor a/c.
But those homes are generally built with that in mind. The open air design of most brick Adobe style buildings tending to mitigate trapped heat very well. I think living in an open air environment like that would be shocking to the senses for way too many Americans.
Quote from: Max Rockatansky on May 03, 2022, 04:29:49 PM
Quote from: kphoger on May 03, 2022, 04:25:49 PM
I find these comments about "necessity" a bit amusing, having spent so much time in the desert climate of northern Mexico–where the large majority of houses have neither heat nor a/c.
But those homes are generally built with that in mind. The open air design of most brick Adobe style buildings tending to mitigate trapped heat very well. I think living in an open air environment like that would be shocking to the senses for way too many Americans.
or... Every house is a giant oven, and the walls and ceiling radiate the heat they've absorbed well into the night.
Quote from: kphoger on May 03, 2022, 04:33:50 PM
Quote from: Max Rockatansky on May 03, 2022, 04:29:49 PM
Quote from: kphoger on May 03, 2022, 04:25:49 PM
I find these comments about "necessity" a bit amusing, having spent so much time in the desert climate of northern Mexico–where the large majority of houses have neither heat nor a/c.
But those homes are generally built with that in mind. The open air design of most brick Adobe style buildings tending to mitigate trapped heat very well. I think living in an open air environment like that would be shocking to the senses for way too many Americans.
or... Every house is a giant oven, and the walls and ceiling radiate the heat they've absorbed well into the night.
I do love those heavy Mexican blankets on cold nights though. We take ours (obtained at a Mercado in Jalisco) camping every year in the Sierra Nevada Mountains.
In Mexico during the summer, I start out naked on top of the covers and still sweating, and sometime around 4 am I put on pants and a shirt and maybe a jacket and burrow under the blankets.
Quote from: abefroman329 on May 03, 2022, 04:27:49 PM
I was today years old when I learned that swamp coolers exist.
I'd say about 20% of houses out here have them. They only work in non-humid climates, so Chicagolanders likely wouldn't have ever heard of them.
Quote from: JayhawkCO on May 03, 2022, 04:46:14 PM
Quote from: abefroman329 on May 03, 2022, 04:27:49 PM
I was today years old when I learned that swamp coolers exist.
I'd say about 20% of houses out here have them. They only work in non-humid climates, so Chicagolanders likely wouldn't have ever heard of them.
They are incredibly common in older homes in the Phoenix Metro Area. I have a portable one I used in my garage in 2020 when I had to convert it to a gym.
Quote from: JayhawkCO on May 03, 2022, 04:46:14 PM
Quote from: abefroman329 on May 03, 2022, 04:27:49 PM
I was today years old when I learned that swamp coolers exist.
I'd say about 20% of houses out here have them. They only work in non-humid climates, so Chicagolanders likely wouldn't have ever heard of them.
Yeah, it looks like they're the equivalent of heat pumps.
Another alternative to central HVAC is a mini-split heat pump system. You have an AC system that has the condenser outside, as per usual. But instead of running it to an air exchanger that leads to ductwork, you pipe the refrigerant to an evaporator head in each room. The neat thing about this is that each head has its own thermostat, so you can set the temperature differently in every room, and turn it off entirely in rooms you don't need cooled for the time being. Since you're pumping pure refrigerant around, the energy losses are much less than through ductwork (since a fair bit of energy is expended keeping the internal surface of the duct the same temperature as the air inside).
The really neat thing about this sort of system is in winter, you just flip a switch and it runs in reverse, essentially air conditioning the outside and radiating heat inside. It ends up being way, way more efficient than burning fuel in a furnace. Now, this doesn't work super well in very cold climates–I imagine the Northeast would be a bit much for it–but it can handle climates as cold as Chicago.
Quote from: Max Rockatansky on May 03, 2022, 04:47:21 PMQuote from: JayhawkCO on May 03, 2022, 04:46:14 PMQuote from: abefroman329 on May 03, 2022, 04:27:49 PMI was today years old when I learned that swamp coolers exist.
I'd say about 20% of houses out here have them. They only work in non-humid climates, so Chicagolanders likely wouldn't have ever heard of them.
They are incredibly common in older homes in the Phoenix Metro Area. I have a portable one I used in my garage in 2020 when I had to convert it to a gym.
In Wichita, which has humid summers, swamp coolers used to be common until they were displaced by A/C (window units in older houses and central in newer ones) beginning around the early to mid-1960's. People simply tolerated a lower standard of comfort in the summer.
Huge variables in the efficiency of central A/C include location, type, and density of insulation; extent of passive solar gain through unshaded windows and the like; and number of full air changes per hour.
Quote from: Scott5114 on May 03, 2022, 05:45:08 PM
The really neat thing about this sort of system is in winter, you just flip a switch and it runs in reverse, essentially air conditioning the outside and radiating heat inside. It ends up being way, way more efficient than burning fuel in a furnace. Now, this doesn't work super well in very cold climates–I imagine the Northeast would be a bit much for it–but it can handle climates as cold as Chicago.
Chicago is colder then a good chunk of the Northeast. I have a heatpump here in NJ and it handles winters fine. It's also broken at the moment so this thread hits home.
My apartment does not have central air conditioning, but I figured a several years ago that it would cost me about $100/month for the energy to run the unit that is in it. Since truly hot/gooey days are usually no more than 4-5/year in this area, I just leave the windows open in good weather.
Nike
Quote from: NJRoadfan on May 03, 2022, 09:13:43 PM
Quote from: Scott5114 on May 03, 2022, 05:45:08 PM
The really neat thing about this sort of system is in winter, you just flip a switch and it runs in reverse, essentially air conditioning the outside and radiating heat inside. It ends up being way, way more efficient than burning fuel in a furnace. Now, this doesn't work super well in very cold climates–I imagine the Northeast would be a bit much for it–but it can handle climates as cold as Chicago.
Chicago is colder then a good chunk of the Northeast. I have a heatpump here in NJ and it handles winters fine. It's also broken at the moment so this thread hits home.
The last apartment I rented in DC (where the winters are milder than they are in NJ or Chicago) had a heat pump and it would stay in emergency mode for most of the winter. It cost me a fortune in electricity bills.
In Arkansas, there would be about a quarter of the population if not for AC, even in the Northwest corner. We have large deciduous trees on the south, southwest, and west of our house rather close in, so their shade keeps our electric bill in the summer below $150 for a 2365 sq ft house. It's the winter that gets us, to the tune of $275 at its worst. We have an all electric house, so we have 2 heat pumps for the different areas of the house. The lower unit is a 2 ton older package unit that keeps the lower (40%) part of the house climate controlled fairly well, although it runs a lot more than the upper part of the house, which was the original part and seems better insulated. The upper split 2.5 ton unit had to be replaced last year, so we went with a higher efficiency 2-stage 3 ton unit to replace the old failed one, and it didn't have to run much at all this winter to keep up with the heating needs of the upper 60% of the house. All this to say, there's a lot that can be done to reduce power usage for climate control, but doing without AC/heat pumps in any non-coastal/southern zone is not a reasonable premise to continued habitability or growth.
Quote from: Max Rockatansky on May 03, 2022, 04:47:21 PM
Quote from: JayhawkCO on May 03, 2022, 04:46:14 PM
Quote from: abefroman329 on May 03, 2022, 04:27:49 PM
I was today years old when I learned that swamp coolers exist.
I'd say about 20% of houses out here have them. They only work in non-humid climates, so Chicagolanders likely wouldn't have ever heard of them.
They are incredibly common in older homes in the Phoenix Metro Area. I have a portable one I used in my garage in 2020 when I had to convert it to a gym.
They tend to be more common in the Tucson area than Phoenix. In Phoenix, more often than not, they are used as a supplement to AC for days that are not too hot.
I live in North Dallas, Texas, and yes, it gets hot here during summer. Not as bad as Houston because of the humidity.
Here's what bothers me. R-22 Freon was phased out in 2020 entirely because of the harm it was causing to the O Zone layer. It's replacement, R410A Puron, is more environmentally friendly, but isn't as efficient, thus you need a more powerful A/C unit to produce the same amount of cooling. Thus, more electric power. :pan: At least when I replaced the air conditioning unit two years ago in my home, it was replaced with a variable-speed unit and a smart thermostat. What next? The energy consumption from residential pool pumps?
Of course, guess what uses plenty of air conditioning? Data centers. Where do you think all of your streaming entertainment comes from?
Quote from: ZLoth on May 05, 2022, 06:16:17 PM
I live in North Dallas, Texas, and yes, it gets hot here during summer. Not as bad as Houston because of the humidity.
Here's what bothers me. R-22 Freon was phased out in 2020 entirely because of the harm it was causing to the O Zone layer. It's replacement, R410A Puron, is more environmentally friendly, but isn't as efficient, thus you need a more powerful A/C unit to produce the same amount of cooling. Thus, more electric power. :pan: At least when I replaced the air conditioning unit two years ago in my home, it was replaced with a variable-speed unit and a smart thermostat. What next? The energy consumption from residential pool pumps?
Of course, guess what uses plenty of air conditioning? Data centers. Where do you think all of your streaming entertainment comes from?
Some flavor of geothermal, using ground as a heat and cold storage. You need to look at a local climate to tell how feasible that is, but should be about right in most of US. Better home insulation is another side of the deal.
Quote from: kalvado on May 05, 2022, 07:22:45 PM
Quote from: ZLoth on May 05, 2022, 06:16:17 PM
I live in North Dallas, Texas, and yes, it gets hot here during summer. Not as bad as Houston because of the humidity.
Here's what bothers me. R-22 Freon was phased out in 2020 entirely because of the harm it was causing to the O Zone layer. It's replacement, R410A Puron, is more environmentally friendly, but isn't as efficient, thus you need a more powerful A/C unit to produce the same amount of cooling. Thus, more electric power. :pan: At least when I replaced the air conditioning unit two years ago in my home, it was replaced with a variable-speed unit and a smart thermostat. What next? The energy consumption from residential pool pumps?
Of course, guess what uses plenty of air conditioning? Data centers. Where do you think all of your streaming entertainment comes from?
Some flavor of geothermal, using ground as a heat and cold storage. You need to look at a local climate to tell how feasible that is, but should be about right in most of US. Better home insulation is another side of the deal.
Lets see here...
Moved to Texas in early 2019
Replaced all the windows in late 2019
Replaced the air conditioner in early 2020
Added home insulation in early 2021
Replacing all the patio doors (in progress)
Anything I'm missing besides solar-powered roof fans to pull out the hot air from the attic?
Quote from: ZLoth on May 05, 2022, 07:33:25 PM
Quote from: kalvado on May 05, 2022, 07:22:45 PM
Quote from: ZLoth on May 05, 2022, 06:16:17 PM
I live in North Dallas, Texas, and yes, it gets hot here during summer. Not as bad as Houston because of the humidity.
Here's what bothers me. R-22 Freon was phased out in 2020 entirely because of the harm it was causing to the O Zone layer. It's replacement, R410A Puron, is more environmentally friendly, but isn't as efficient, thus you need a more powerful A/C unit to produce the same amount of cooling. Thus, more electric power. :pan: At least when I replaced the air conditioning unit two years ago in my home, it was replaced with a variable-speed unit and a smart thermostat. What next? The energy consumption from residential pool pumps?
Of course, guess what uses plenty of air conditioning? Data centers. Where do you think all of your streaming entertainment comes from?
Some flavor of geothermal, using ground as a heat and cold storage. You need to look at a local climate to tell how feasible that is, but should be about right in most of US. Better home insulation is another side of the deal.
Lets see here...
Moved to Texas in early 2019
Replaced all the windows in late 2019
Replaced the air conditioner in early 2020
Added home insulation in early 2021
Replacing all the patio doors (in progress)
Anything I'm missing besides solar-powered roof fans to pull out the hot air from the attic?
Oh, attic fans seem to be surprisingly controversial thing. Intuition tells me it's a great idea, but a lot of writeups disagree with the approach.
IR inspection of the house and blow test may tell you something else.
Quote from: abefroman329 on May 05, 2022, 12:07:25 PM
The last apartment I rented in DC (where the winters are milder than they are in NJ or Chicago) had a heat pump and it would stay in emergency mode for most of the winter. It cost me a fortune in electricity bills.
Your heatpump and/or thermostat was broken or your place had zero insulation. Even the bottom of the barrel system I have can maintain the setpoint without the heating strips coming on well below freezing.
Quote from: NJRoadfan on May 05, 2022, 08:37:08 PM
Quote from: abefroman329 on May 05, 2022, 12:07:25 PM
The last apartment I rented in DC (where the winters are milder than they are in NJ or Chicago) had a heat pump and it would stay in emergency mode for most of the winter. It cost me a fortune in electricity bills.
Your heatpump and/or thermostat was broken or your place had zero insulation. Even the bottom of the barrel system I have can maintain the setpoint without the heating strips coming on well below freezing.
" Zero insulation" would be my guess - when they renovated the building, they didn't spend very much time or money on the exterior walls. We would also get a comprehensive rat infestation every few months