Shortage of air conditioner parts expected this summer(kswo.com)
kswo.com
Shortage of air conditioner parts expected this summer
https://www.kswo.com/2021/05/28/shortage-of-air-conditioner-parts-expected-this-summer/
171 comments
We really need to move towards passive solar design. Expending energy to cool the house that heats the planet is so counterproductive, especially as human populations climb and human-caused climate change escalates.
Some tried. And failed. [0]
Thankfully, they got lucky and built right next to a trillion dollar company's headquarters, so they will still be able to sell at a premium.
[0] http://archive.kuow.org/post/modern-seattle-building-doesn-t...
Thankfully, they got lucky and built right next to a trillion dollar company's headquarters, so they will still be able to sell at a premium.
[0] http://archive.kuow.org/post/modern-seattle-building-doesn-t...
Thermodynamics bud.
Yeah, but the backwards compatibility is a pain. There's so much housing stock that can't just be torn down and rebuilt. We will probably move to that but considering how slow housing changes move, it will take a century.
All the more reason to start now.
I also think just doing things like living more spartan can help but I don't know how to sell people on that idea.
I also think just doing things like living more spartan can help but I don't know how to sell people on that idea.
>Expending energy to cool the house that heats the planet is so counterproductive
Please don't spread this anti-environmental claptrap. Expending energy does not "heat the planet", as a quick consideration of the night side of Mercury would reveal. It's greenhouse gases in the atmosphere that heat the planet, and they'd do so even if humanity vanished tomorrow. To the extent that "energy consumption" is at all related it's purely in terms of externalities in energy generation, but we have the tools to deal with those.
There has long been this strain of moral Puritanism in environmentalist movements wherein people must suffer and "return to nature" and such to be Green. But more often then not no, we don't. So I consider that to be an anti-environmental, counterproductive stance since it creates a false choice wherein people are told everyone must give up often key parts of their lives entirely or else they're bad. Given that, it's not surprising many will plump for the status quo. But in reality it's completely fine from an environmental point of view for everyone to spend their luxury energy budget as they wish, and indeed gaining/growing that is a key bit of human progress. What needs to be done is ensure that energy budget, unlike today, is actually environmentally (and in particular GHG) neutral. Societies can work from there.
Please don't spread this anti-environmental claptrap. Expending energy does not "heat the planet", as a quick consideration of the night side of Mercury would reveal. It's greenhouse gases in the atmosphere that heat the planet, and they'd do so even if humanity vanished tomorrow. To the extent that "energy consumption" is at all related it's purely in terms of externalities in energy generation, but we have the tools to deal with those.
There has long been this strain of moral Puritanism in environmentalist movements wherein people must suffer and "return to nature" and such to be Green. But more often then not no, we don't. So I consider that to be an anti-environmental, counterproductive stance since it creates a false choice wherein people are told everyone must give up often key parts of their lives entirely or else they're bad. Given that, it's not surprising many will plump for the status quo. But in reality it's completely fine from an environmental point of view for everyone to spend their luxury energy budget as they wish, and indeed gaining/growing that is a key bit of human progress. What needs to be done is ensure that energy budget, unlike today, is actually environmentally (and in particular GHG) neutral. Societies can work from there.
Charles C. Mann would describe that strain of moralist, prosperity = ruin, return-to-nature type thinking as a “Prophet” mindset, traceable back to even before William Vogt and the early 1900s of, among other things, eugenics, Malthusianism, and an unshakeable fear of the masses in e.g. Delhi (but not Paris!).
On the other side, and especially here on HN and the like, the tech building, win-win seeking, prosperity maximalist “Wizards” essentially just keep trying to build their way out of problems, e.g. massive gains in ag productivity of pesticide treated, fossil fuel fertilized, genetically modified high yielding, mono cropped strains that have already saved a billion.
Cannot recommend “The Wizard and the Prophet” enough, a great history of environmentalism in the 20th century and how this split evolved, and it’s not nearly as biased as I am (though still clearly leaning “Wizard” in its text).
https://www.goodreads.com/book/show/34959327-the-wizard-and-...
On the other side, and especially here on HN and the like, the tech building, win-win seeking, prosperity maximalist “Wizards” essentially just keep trying to build their way out of problems, e.g. massive gains in ag productivity of pesticide treated, fossil fuel fertilized, genetically modified high yielding, mono cropped strains that have already saved a billion.
Cannot recommend “The Wizard and the Prophet” enough, a great history of environmentalism in the 20th century and how this split evolved, and it’s not nearly as biased as I am (though still clearly leaning “Wizard” in its text).
https://www.goodreads.com/book/show/34959327-the-wizard-and-...
I share the larger point but it seems like you're reading a LOT more into that comment. They didn't say anything about, say, giving up cool houses — simply a preference for passive rather than active cooling. The last part is especially relevant in cities where poorly-designed AC units dumping heat into crowded environments increases the ambient temperature and thus AC load.
While you're not always wrong to say that expending energy doesn't have to heat the planet, it's wrong in practice for the substantial percentage of the world where energy production emits greenhouse gases. Until that percentage is zero, there is a considerable amount of good which can be done by using less energy and we have enormous efficiency wins possible without any real suffering.
As a simple example, a geothermal heat pump system will require less power than a convention gas heater and AC system even if your thermostat is set to the exact same levels. A building which is designed with passive cooling (heavy earth walls, use of ground/water cooling) or windows placed to optimize for winter sun angles but not summer will require less power to maintain a comfortable temperature. As long as your power is not completely emission free, that's probably a win — and if you are trying to fit within the solar/wind/etc. power you can generate on-site the lower usage will make that easier.
While you're not always wrong to say that expending energy doesn't have to heat the planet, it's wrong in practice for the substantial percentage of the world where energy production emits greenhouse gases. Until that percentage is zero, there is a considerable amount of good which can be done by using less energy and we have enormous efficiency wins possible without any real suffering.
As a simple example, a geothermal heat pump system will require less power than a convention gas heater and AC system even if your thermostat is set to the exact same levels. A building which is designed with passive cooling (heavy earth walls, use of ground/water cooling) or windows placed to optimize for winter sun angles but not summer will require less power to maintain a comfortable temperature. As long as your power is not completely emission free, that's probably a win — and if you are trying to fit within the solar/wind/etc. power you can generate on-site the lower usage will make that easier.
[deleted]
This may end up a good thing for some people. About 5 years ago, I had a heating/cooling contractor come out to repair my A/C unit. It had failed just coming into a very hot night, I called a local company which told me "first thing in the morning".
It got hot.
I went to YouTube and found a few videos -- I had already known about the two fuses leading to the A/C unit, mine were fine. I hadn't known about a capacitor that was used to assist the fan in starting and discovered that taking a stick off the ground, starting the A/C and whacking the fan was enough to make it run[0]. I ordered the replacement from Amazon[1].
I had forgotten to cancel my appointment and the gentleman with the company arrived mid-morning. Being that the unit was all of 5 years old, and I had a good understanding what was wrong, I wondered what I'd be told so I acted dumb. Wouldn't you know it? It turns out that "the compressor is no good", and that "the kind of compressor used in this isn't made any longer"[2]. I told him, "Ah, that's too bad, I guess I'll have to have my Dad come out and replace it" and sent him on his way. Two days later I installed the first of the two capacitors I purchased and had working A/C until early this summer. This time when it failed, I took the panel off, saw the cap was bulging, and replaced it. Fixed. For those keeping score, that's 10 years on an A/C unit that apparently had a bad compressor and required replacement 5 years ago.
The moral of the story is that a few minutes of time on YouTube can save a lot of money and literal sweat. If you have a professional that you trust, great -- if you don't, get a second opinion before dropping a large amount of money simply because the A/C repair company sent a sales-person out when what was needed was a technician.
[0] It wouldn't start on its own, but I could get the house down a few degrees below comfortable and leave it off for the night, at least.
[1] I called a few places the following morning and nobody carried capacitors that size, locally; Amazon was it for guaranteed 2-day shipping; I miss Prime. It also appears my capacitor isn't affected by the parts shortage -- there's several on EBay and Amazon at present.
[2] The technician (who was actually a sales-person) attempted to mix up energy efficiency standards and actual coolant formulations; I don't recall exactly what he said but I recall searching the finer points and discovering that I had a very high-end A/C unit, and the entire compressor was available in used/new forms. Oh, and mine is still "just fine".
It got hot.
I went to YouTube and found a few videos -- I had already known about the two fuses leading to the A/C unit, mine were fine. I hadn't known about a capacitor that was used to assist the fan in starting and discovered that taking a stick off the ground, starting the A/C and whacking the fan was enough to make it run[0]. I ordered the replacement from Amazon[1].
I had forgotten to cancel my appointment and the gentleman with the company arrived mid-morning. Being that the unit was all of 5 years old, and I had a good understanding what was wrong, I wondered what I'd be told so I acted dumb. Wouldn't you know it? It turns out that "the compressor is no good", and that "the kind of compressor used in this isn't made any longer"[2]. I told him, "Ah, that's too bad, I guess I'll have to have my Dad come out and replace it" and sent him on his way. Two days later I installed the first of the two capacitors I purchased and had working A/C until early this summer. This time when it failed, I took the panel off, saw the cap was bulging, and replaced it. Fixed. For those keeping score, that's 10 years on an A/C unit that apparently had a bad compressor and required replacement 5 years ago.
The moral of the story is that a few minutes of time on YouTube can save a lot of money and literal sweat. If you have a professional that you trust, great -- if you don't, get a second opinion before dropping a large amount of money simply because the A/C repair company sent a sales-person out when what was needed was a technician.
[0] It wouldn't start on its own, but I could get the house down a few degrees below comfortable and leave it off for the night, at least.
[1] I called a few places the following morning and nobody carried capacitors that size, locally; Amazon was it for guaranteed 2-day shipping; I miss Prime. It also appears my capacitor isn't affected by the parts shortage -- there's several on EBay and Amazon at present.
[2] The technician (who was actually a sales-person) attempted to mix up energy efficiency standards and actual coolant formulations; I don't recall exactly what he said but I recall searching the finer points and discovering that I had a very high-end A/C unit, and the entire compressor was available in used/new forms. Oh, and mine is still "just fine".
Unless you know what you're doing (and I'm not saying that you in particular don't) this is incredibly dangerous. The capacitors in A/C units can store enough energy to kill you, even if the A/C has been unplugged for hours or days.
I would not try this at home.
I would not try this at home.
It sounds like this is a motor start capacitor, which is going to be connected to the motor and discharged if the power is off. Do the research instead of spreading paranoia and FUD.
That's good to know, I think some of the warning still stands. It doesn't hurt to be a little paranoid, especially if this isn't your wheelhouse day-to-day. It's certainly not mine, though, I've done enough to be both a danger to myself and to others.
I have only worked with a motor start capacitor in the context of mine and a few neighbor's A/C units. Anything I do is small circuits, DC, and not a mess at that. Frankly, the look of the thing upon removal made me fearful that nothing about what this thing is supposed to do could be trusted (large bulges on both sides).
I've worked with others of about this size, and smoked some hair on my arm with one fully removed from a Mitsubishi rear projection television (with an actual hole in what probably constituted its main board) from somewhere in the early 90s. It's the only time I've held onto a disconnected component "just right" to get a surprise and I'm not certain I touched more than hair. It didn't have anything but 400V written on it, no idea what purpose it served, honestly yanked it "because I didn't have one" and I'd never seen one that large up to that point. And I never found a use for it; it's probably still sitting in my battery box in the basement :).
Bottom line: the AC unit service door, and several other places around the unit, and within its service manual have affixed, sometimes etched, warning labels. At least some of those were added after someone died. It's worth a good read and a little bit of caution.
I have only worked with a motor start capacitor in the context of mine and a few neighbor's A/C units. Anything I do is small circuits, DC, and not a mess at that. Frankly, the look of the thing upon removal made me fearful that nothing about what this thing is supposed to do could be trusted (large bulges on both sides).
I've worked with others of about this size, and smoked some hair on my arm with one fully removed from a Mitsubishi rear projection television (with an actual hole in what probably constituted its main board) from somewhere in the early 90s. It's the only time I've held onto a disconnected component "just right" to get a surprise and I'm not certain I touched more than hair. It didn't have anything but 400V written on it, no idea what purpose it served, honestly yanked it "because I didn't have one" and I'd never seen one that large up to that point. And I never found a use for it; it's probably still sitting in my battery box in the basement :).
Bottom line: the AC unit service door, and several other places around the unit, and within its service manual have affixed, sometimes etched, warning labels. At least some of those were added after someone died. It's worth a good read and a little bit of caution.
Even if motor start capacitors are safe to touch, if you don't know what you're doing you might accidentally make contact with a dangerous capacitor. And the parent comment didn't clearly state to only change motor start capacitors -- they seem to endorse changing all capacitors without any warning.
Please don't accuse others of spreading FUD when this type of repair is legitimately dangerous.
Please don't accuse others of spreading FUD when this type of repair is legitimately dangerous.
You might get run over by a bus on your way to the store to buy the capacitor, too. Don't overlook that possibility while you're jumping at shadows.
Capacitors such as what? A normal AC system is basically two fans, a compressor, and a bunch of pipes, right?
A motor capacitor: https://en.wikipedia.org/wiki/Run_capacitor. Both the fan motor (external and internal fans) and the compressor itself will each likely have one. And should they fail, the motors will not start, which gives the appearance of a failed motor for the fans or the compressor, when what needs to be changed is a $5 capacitor.
No, that's my point, they were arguing that there were other kinds of capacitor to worry about.
My mistake; I assumed that there were other capacitors in maybe a power supply attached to the AC unit.
[deleted]
It's actually a simple fix. You can buy the capacitor on AMZN, kill the main breaker in the box near the AC unit. Get a screw driver and disconnect it and if you want you can then cross the leads with the screw driver to make sure it's drained. Install the new one and flip the breaker and your set to go. Cap costs around $20 and you you saved yourself a $100 service call.
Shorting a capacitor of sufficient size can send molten metal bits flying around as the leads melt under high current, or even make the capacitor explode. I’m all for DIY repairs, but if you’re going to do this at least wear safety goggles. Also, short the capacitor after turning the power off and before unscrewing it—that’s the time you’re most likely to complete the circuit with a fleshy part.
Edit: There might also be other bits in the system with residual power that refill the capacitor even after unplugging the mains, so a voltmeter is a good idea as well.
Edit: There might also be other bits in the system with residual power that refill the capacitor even after unplugging the mains, so a voltmeter is a good idea as well.
I'm sorry, but you speak like you're living in a movie.
Shorting a starter cap won't do anything of what you said. These caps are actually small (couple hundred uF). At the worst you'll produce a small spark. nothing more.
Shorting a starter cap won't do anything of what you said. These caps are actually small (couple hundred uF). At the worst you'll produce a small spark. nothing more.
If you think you know exactly what's going on with a strange cap and want to take that risk, go for it. Me, I like my forearms unscarred.
> There might also be other bits in the system with residual power that refill the capacitor even after unplugging the mains, so a voltmeter is a good idea as well.
Like what, when it was already turned off? And especially, what do you imagine recharging a significant capacitor to more than 50 volts?
Like what, when it was already turned off? And especially, what do you imagine recharging a significant capacitor to more than 50 volts?
It's not a big deal as long as you're aware of the danger and discharge the capacitor before removing it. The capacitor is usually the culprit, especially in hot environments like where I live.
That falls under "if you know what you're doing."
All modern appliances should have a bleed resistor fitted to drain the capacitor within a few seconds of the power being switched off.
It is theoretically possible, but if your start/run capacitor has failed, it is not going to be dangerous and it is designed to be replaced.
Wear (rubber) gloves, short circuit anything you're going to touch with an insulated screwdriver, and you'll be fine.
A new capacitor is about $20 vs. $250+ for any service visit.
Wear (rubber) gloves, short circuit anything you're going to touch with an insulated screwdriver, and you'll be fine.
A new capacitor is about $20 vs. $250+ for any service visit.
Come on, it's an AC single phase assist cap, not a DC cap of >1000 uF like those found in camera flash units. Just short it with a load before you touch it to be 100% sure.
Come to think of it are medium sized high voltage capacitors really that much of an electrocution risk in the first place?
I mean sure as anything they can throw you back into your seat and cause a relatively decent burn but in practice are they really an electrocution risk?
You're not going to get trapped and unable to let go.
Edit:
Looks like the biggest risk from a high voltage DC discharge is myocardial depolarization, and that's dependent on the current path and the timing of the heart rythym, but that's typically at energies an order of magnitude more than a charged typical motor capacitor
I mean sure as anything they can throw you back into your seat and cause a relatively decent burn but in practice are they really an electrocution risk?
You're not going to get trapped and unable to let go.
Edit:
Looks like the biggest risk from a high voltage DC discharge is myocardial depolarization, and that's dependent on the current path and the timing of the heart rythym, but that's typically at energies an order of magnitude more than a charged typical motor capacitor
>75 mA across the heart might be fatal.
An AC motor capacitor would probably just give you a short shock since it's only used to introduce a phase shift on the auxiliary phase in single phase AC motors (what the OP is talking about) or for power factor correction in 2/3 phase AC motors. AC switches every 20 ms from positive to negative so the cap only stores very little power. I'd be more weary of capacitors in DC circuits.
An AC motor capacitor would probably just give you a short shock since it's only used to introduce a phase shift on the auxiliary phase in single phase AC motors (what the OP is talking about) or for power factor correction in 2/3 phase AC motors. AC switches every 20 ms from positive to negative so the cap only stores very little power. I'd be more weary of capacitors in DC circuits.
[deleted]
Ah, yes. This is a point I really should have made.
If you've been "bit" by a small cap on a circuit board, imagine one as big as an adult's fist. I don't recall the output of this thing but one needn't read the label to know that if I can't completely enclose this thing in my hands, it's probably not something one should...enclose in ones hands? It is also in a nice metal container that's probably under more pressure than it should be; mine were always bulging.
With board mounted caps, a lot of this stuff lands in the "leaving pizza out overnight" category. I've only had one (small one) truly explode[0] due to age/being defective; several that I blew up in electronics class when the teacher's head was turned, but hey. And about a flobbidy-gillion that bulge, you could lick the leads (that's sarcasm, don't actually do this).
Now, fan caps/mostors like this -- I've been bit by (a 400V cap that was "not dead yet") -- I don't know that I actually touched the leads so much as some hair on my exposed arm made contact (it's why I wear my long welding gloves!). ...There's that moment well after you've registered the burning sensation and smelled the hair that you say a prayer of thanks to God while panicking that the business end is not yet any safer than it was a second ago.
The (somewhat unsafe) procedure I used was: Cut the power, pop the fuses, pulled the wires in the order I had in my notes from last time (with thick welding gloves[0]), pre-cut electrical tape to cover the three leads (model has lots of distance, it's a big cap). The cap is connected by three wires, far from the rest of the electronics, easy to get to, easy to remove/re-secure the wiring, admittedly -- easy to get a little too comfortable.
Carefully handle those leads; hopefully goes without saying -- even if the cap isn't bulging -- avoid heat-based treatments (hot glues/heat shrink). I tape the hell out of the big ones. I've only had to personally handle a small number of these, but there's a TV repair shop in the area that does free electronics recycling. I told the puzzled 15 year old at the counter what it was, he looked puzzled, so I explained that it can explode like a hover-board battery and he shrugged. I guess...good enough.
[0] In a manner that might have been a fire hazard, and were it exposed, could have taken an eye out. In my case, a moderate "pop", a black spot on the board, smoke, and shrapnel throughout the small case.
If you've been "bit" by a small cap on a circuit board, imagine one as big as an adult's fist. I don't recall the output of this thing but one needn't read the label to know that if I can't completely enclose this thing in my hands, it's probably not something one should...enclose in ones hands? It is also in a nice metal container that's probably under more pressure than it should be; mine were always bulging.
With board mounted caps, a lot of this stuff lands in the "leaving pizza out overnight" category. I've only had one (small one) truly explode[0] due to age/being defective; several that I blew up in electronics class when the teacher's head was turned, but hey. And about a flobbidy-gillion that bulge, you could lick the leads (that's sarcasm, don't actually do this).
Now, fan caps/mostors like this -- I've been bit by (a 400V cap that was "not dead yet") -- I don't know that I actually touched the leads so much as some hair on my exposed arm made contact (it's why I wear my long welding gloves!). ...There's that moment well after you've registered the burning sensation and smelled the hair that you say a prayer of thanks to God while panicking that the business end is not yet any safer than it was a second ago.
The (somewhat unsafe) procedure I used was: Cut the power, pop the fuses, pulled the wires in the order I had in my notes from last time (with thick welding gloves[0]), pre-cut electrical tape to cover the three leads (model has lots of distance, it's a big cap). The cap is connected by three wires, far from the rest of the electronics, easy to get to, easy to remove/re-secure the wiring, admittedly -- easy to get a little too comfortable.
Carefully handle those leads; hopefully goes without saying -- even if the cap isn't bulging -- avoid heat-based treatments (hot glues/heat shrink). I tape the hell out of the big ones. I've only had to personally handle a small number of these, but there's a TV repair shop in the area that does free electronics recycling. I told the puzzled 15 year old at the counter what it was, he looked puzzled, so I explained that it can explode like a hover-board battery and he shrugged. I guess...good enough.
[0] In a manner that might have been a fire hazard, and were it exposed, could have taken an eye out. In my case, a moderate "pop", a black spot on the board, smoke, and shrapnel throughout the small case.
Just to disclaim a little more -- I definitely would do this at home, and the first time I did something like this was before I started doing any real circuit work at home.
I take into account the typical audience of the site, though. Most of us tinker/work with highly complex things that require good research skills even if they don't touch electronics. The basics of how a fan capacitor works, how to handle one safely -- including testing, and discharging, can be done for less than $100 in parts including the required resistor/multi-meter -- in my case. But after inspection and planning, I opted for skipping some precautions and relying on "being careful"[0] which I don't recommend, but how many deaths is that, really, if we all try it? (/sarcasm)
In the case of my unit, there was maybe three seconds where -- if a reasonable enough charge were present (and I had every reason to believe it held enough to hurt ... a lot ... which is motivation enough) -- I was in danger of receiving it if started pouring on me spontaneously on a clear day -- I didn't have remove the cap from the unit to secure the leads. I suspect a lot of A/C units are similar, but YMMV and I'd be willing to bet, again, most readers of this site possess the wisdom to judge the danger for themselves after suitable reading/watching.
[0] Common sense which starts with Rule #1: Always have a physical witness if you're working on something that can kill you and ends with #2: Use them to double-check your research if it isn't obvious stuff (or my personal favorite, have them handle the dangerous stuff).
I take into account the typical audience of the site, though. Most of us tinker/work with highly complex things that require good research skills even if they don't touch electronics. The basics of how a fan capacitor works, how to handle one safely -- including testing, and discharging, can be done for less than $100 in parts including the required resistor/multi-meter -- in my case. But after inspection and planning, I opted for skipping some precautions and relying on "being careful"[0] which I don't recommend, but how many deaths is that, really, if we all try it? (/sarcasm)
In the case of my unit, there was maybe three seconds where -- if a reasonable enough charge were present (and I had every reason to believe it held enough to hurt ... a lot ... which is motivation enough) -- I was in danger of receiving it if started pouring on me spontaneously on a clear day -- I didn't have remove the cap from the unit to secure the leads. I suspect a lot of A/C units are similar, but YMMV and I'd be willing to bet, again, most readers of this site possess the wisdom to judge the danger for themselves after suitable reading/watching.
[0] Common sense which starts with Rule #1: Always have a physical witness if you're working on something that can kill you and ends with #2: Use them to double-check your research if it isn't obvious stuff (or my personal favorite, have them handle the dangerous stuff).
[deleted]
My dad is a retired general contractor, and he’s had many friends that had A/C companies quote a whole new condenser, when it was just the capacitor.
The other thing he drills is to change. your. filters. Buy a box of them, put it next to the air handler. Not doing this during spring and fall will kill your central air. It screws up the careful balance of pressures and temperatures that your installer had to establish. Eventually your evaporator or condenser blows a hole and vents itself… which will probably kill your condenser too. Five minutes of effort, twice a year and you can add years to your system’s life.
The other thing he drills is to change. your. filters. Buy a box of them, put it next to the air handler. Not doing this during spring and fall will kill your central air. It screws up the careful balance of pressures and temperatures that your installer had to establish. Eventually your evaporator or condenser blows a hole and vents itself… which will probably kill your condenser too. Five minutes of effort, twice a year and you can add years to your system’s life.
I have been told by my commercial HVAC contractor not to use the fancy high MERV filters either as air handler systems are not designed to filter air, so if the filter is too good, it restricts air flow so much that it can cause stain on the system.
If you want to filter air, buy a separate air filter, and let the air handler just handle heating and cooling (if that is what it is designed for).
If you want to filter air, buy a separate air filter, and let the air handler just handle heating and cooling (if that is what it is designed for).
"Strain on the system" is one of these phrases that the field techs use to excuse just about anything. They want to sell you something new and they want a reason that purchase is your fault.
If you have an excessive pressure drop across the filter you'll have slightly lower airflow across the D/X coil which results in less energy extracted per second the compressor's running.
That doesn't "strain the system" in any straightforward way. It's going to increase your compressor runtime, yes, and the delta between your return and discharge temperatures will be less. (The discharge won't feel as cold)
Mostly excess pressure drop is caused by dirty filters. A clean MERV won't drop the pressure low enough to result in the D/X icing up so you're still cooling.
Depending on your local thermal load, especially in shoulder season (spring, fall) slightly lower airflow might even improve your system's lifetime because it might reduce short-cycling. Every cooling cycle counts towards eventual failure. That's going to depend on your controller, though.
Working out the details for your system is an involved engineering exercise. A field tech telling you "MERVs are no good" isn't doing that mental work.
A MERV will get dirty and saturate faster so if you're using MERVs you need to change them more often. A saturated filter will slow air enough to ice the coil and then you have a real problem.
All that said... if you want very clean air, buy a box fan or squirrel fan and tape a MERV filter to it. Squirrel fans deal with this better but the shape's less convenient. Stick it in a forgotten corner.
Don't buy a stand-alone commercial air filtration device. They're a total rip-off.
If you have an excessive pressure drop across the filter you'll have slightly lower airflow across the D/X coil which results in less energy extracted per second the compressor's running.
That doesn't "strain the system" in any straightforward way. It's going to increase your compressor runtime, yes, and the delta between your return and discharge temperatures will be less. (The discharge won't feel as cold)
Mostly excess pressure drop is caused by dirty filters. A clean MERV won't drop the pressure low enough to result in the D/X icing up so you're still cooling.
Depending on your local thermal load, especially in shoulder season (spring, fall) slightly lower airflow might even improve your system's lifetime because it might reduce short-cycling. Every cooling cycle counts towards eventual failure. That's going to depend on your controller, though.
Working out the details for your system is an involved engineering exercise. A field tech telling you "MERVs are no good" isn't doing that mental work.
A MERV will get dirty and saturate faster so if you're using MERVs you need to change them more often. A saturated filter will slow air enough to ice the coil and then you have a real problem.
All that said... if you want very clean air, buy a box fan or squirrel fan and tape a MERV filter to it. Squirrel fans deal with this better but the shape's less convenient. Stick it in a forgotten corner.
Don't buy a stand-alone commercial air filtration device. They're a total rip-off.
Fair, but just remember that the purpose of a filter (in this context) is to keep particulate matter out of the evaporator to protect it from damage. Since cleaner air is just a side-effect of that protective effect, I would agree that there’s probably better ways to clean air if that’s really your goal.
It’s kind of like how (traditional) circuit breakers are designed to protect the premises wiring from catching fire when too much current passes through them. They could care less if you get electrocuted or you overload a higher-gauge extension cord (GFCI and arc-fault are another story though).
It’s kind of like how (traditional) circuit breakers are designed to protect the premises wiring from catching fire when too much current passes through them. They could care less if you get electrocuted or you overload a higher-gauge extension cord (GFCI and arc-fault are another story though).
It's not uncommon for HVAC, automotive, and other "repair" trades to assume customers are idiots and try to fleece them as much as possible. There are lots of YouTube videos about that too. Honest and skilled technicians are unfortunately very difficult to find.
It's not uncommon for HVAC, automotive, and other "repair" trades to be idiots themselves and only capable of replacing major components rather than performing proper diagnostics. Yes, most repair technicians are competent but quality is spotty.
Yes, the ones that fleece you don't know any better or the repair is so specific that the company doesn't offer that service. For example Louis Rossman offers component level repairs but any authorized Apple repair shop is going to replace entire boards and they can't fix some issues because Apple doesn't give them the replacement parts.
Yeah- AC capacitors cost $3-4 at HVAC supply shops. Your AC will usually have 2-3 of different sizes.
I've had pros quote me $600-700 for the repair when they thought they had me in a tight spot, and I already knew it was a cheap fix.
Burt even reputable AC guys are going to charge $100-200 for replacing capacitors.
It's a five minute fix one you know how to do it safely.
Also: if you have a noisy/ whirring compressor, the capacitor is likely the source. Either it's going out, or the last guy put in the wrong size capacitor (because he didn't have the correct one already on the truck).
I've had pros quote me $600-700 for the repair when they thought they had me in a tight spot, and I already knew it was a cheap fix.
Burt even reputable AC guys are going to charge $100-200 for replacing capacitors.
It's a five minute fix one you know how to do it safely.
Also: if you have a noisy/ whirring compressor, the capacitor is likely the source. Either it's going out, or the last guy put in the wrong size capacitor (because he didn't have the correct one already on the truck).
I have a fun story with those capacitors.
In school I was demonstrating a little rail gun powered by one of those caps. When done, I went to take a seat.
Upon sitting, I placed my hand on top of the capacitor, and no joke the muscle spasm shot me up so that I was standing again.
In school I was demonstrating a little rail gun powered by one of those caps. When done, I went to take a seat.
Upon sitting, I placed my hand on top of the capacitor, and no joke the muscle spasm shot me up so that I was standing again.
Mine shut off on a hot day. Tons of condensation was getting into the blower. Three part fix: replace shorted door switch, install drain barb for intake, blow out debris in tubes.
Points to a lesson that's become pretty important to me: Learn enough to nearly diagnose the problem and understand what the solutions could be (even if you can't fix it yourself).
So far I've found this applies to legal services, automotive work & health services as well.
So far I've found this applies to legal services, automotive work & health services as well.
I found out about forced obsolescence from my dad. He had an old LCD screen of mine that didn't work anymore, capacitors were bulging. Turns out they were (intentionally?) under capacity, made to fail after the 3 year warranty. He replaced them with over capacity capacitors and iirc the screen still works just fine. Pretty sure that if it's not the capacitors, the tiny switches that don't feel sturdy at all would be the ones to break.
Mind you, since then I've gotten some more expensive screens, I have one from Dell that's been going daily for ten years now and is still fine.
Mind you, since then I've gotten some more expensive screens, I have one from Dell that's been going daily for ten years now and is still fine.
Where I live right now, if my AC broke I would not be able to live in my home; It gets so hot you could easily die of heat exhaustion. I sure hope it doesn't break this summer for whatever reason
If you use good insulation techniques while building, you barely need AC. Grew up in a country with harsh winters and hot summers -- you just open small window at night and close it in the morning, and your house stays cool for the day.
Doesn't work in places like Phoenix where it's 100F at 10pm and doesn't dip below 80F or 90F before the rising the next day.
Fair point. But I bet you'd need 10x less AC output with better insation than commonly built houses in Arizona. How do you think?
Doesn't work where the humidity is high either.
Well-conceived and built https://en.wikipedia.org/wiki/Ground-coupled_heat_exchanger are incredibly efficient.
The breakdown of global supply chains and service workforces continues. My wife and I have embraced learning to build and fix things ourselves whenever possible. It's worked well for us but there is a limit--I'm not a licensed plumber or electrician, for example. How much longer before modern life is no longer possible, I wonder...
It seems like a pretty big jump from "wait a few days for air conditioner parts" to "modern life is no longer possible"!
> It seems like a pretty big jump from "wait a few days for air conditioner parts" to "modern life is no longer possible"!
Where there are delays, they aren't necessarily “a few days” but months, and, yeah, life in, say, California's Central Valley in a hot, dry summer without AC is somewhere between unpleasant and intolerable.
Where there are delays, they aren't necessarily “a few days” but months, and, yeah, life in, say, California's Central Valley in a hot, dry summer without AC is somewhere between unpleasant and intolerable.
Not just California.
I live in Michigan -- about once every 7 years we get unseasonably warm summers. It's been 85-95 degrees through June with the sort of humidity that makes it feel like you have to actively think about breathing.
People die from heatwaves; modern conveniences like A/C make that sort of thing a lot less common these days, so while the original comment writer's attitude that "modern life is no longer possible" may have been meant to poke fun at "first world problems" -- yeah, I get it, we all have it pretty good -- these "conveniences" do more than just "make quality of life a little better"[0].
[0] Not saying there aren't downsides, either, but I'm not willing to give up my A/C for 'em.
I live in Michigan -- about once every 7 years we get unseasonably warm summers. It's been 85-95 degrees through June with the sort of humidity that makes it feel like you have to actively think about breathing.
People die from heatwaves; modern conveniences like A/C make that sort of thing a lot less common these days, so while the original comment writer's attitude that "modern life is no longer possible" may have been meant to poke fun at "first world problems" -- yeah, I get it, we all have it pretty good -- these "conveniences" do more than just "make quality of life a little better"[0].
[0] Not saying there aren't downsides, either, but I'm not willing to give up my A/C for 'em.
The 2003 heat wave in Europe apparently killed about 70,000 people. Home AC is somewhat less common in Europe.
https://doi.org/10.1016/j.crvi.2007.12.001
https://doi.org/10.1016/j.crvi.2007.12.001
Not just home A/C but many of the hotels I visited did not have A/C (or it was set for the whole building, and way too hot at that).
We visited the UK in late May during one of those heat waves and got stuck on the London Underground in a very hot train. Lots of fun!
We visited the UK in late May during one of those heat waves and got stuck on the London Underground in a very hot train. Lots of fun!
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This person lives in a mild climate zone
There's at least a billion people that live nearer to the equator than anyone in Europe or the USA and don't have air conditioning.
Latitude isn't the only thing that determines climate. Phoenix AZ is a lot hotter than Ecuador, Kenya, or Indonesia.
Also, this isn't just about cooling; it's about heating, too. Imagine living in Saskatoon SK without a working heat source. Nobody does that. If you're not relying on electric/gas heat in such places, you're relying on fire.
Also, this isn't just about cooling; it's about heating, too. Imagine living in Saskatoon SK without a working heat source. Nobody does that. If you're not relying on electric/gas heat in such places, you're relying on fire.
Heating is extremely simple compared to cooling. There will never be a part shortage for heating appliances. A space heater is basically some high-resistance wire and a fan.
> There's at least a billion people that live nearer to the equator than anyone in Europe or the USA and don't have air conditioning.
Nearer to the equator pretty consistently means less seasonal variation in temperature, it does not mean higher summer peak temperatures.
Nearer to the equator pretty consistently means less seasonal variation in temperature, it does not mean higher summer peak temperatures.
One important factor is that there are design decisions made which are optimized for air conditioning such as buildings without any windows that open.
They're also less economically productive than people in cooler climate or with air conditioning.
Lee Kuan Yew, founder of modern Singapore: "Air conditioning was a most important invention for us, perhaps one of the signal inventions of history. It changed the nature of civilization by making development possible in the tropics. Without air conditioning you can work only in the cool early-morning hours or at dusk. The first thing I did upon becoming prime minister was to install air conditioners in buildings where the civil service worked. This was key to public efficiency."
Lee Kuan Yew, founder of modern Singapore: "Air conditioning was a most important invention for us, perhaps one of the signal inventions of history. It changed the nature of civilization by making development possible in the tropics. Without air conditioning you can work only in the cool early-morning hours or at dusk. The first thing I did upon becoming prime minister was to install air conditioners in buildings where the civil service worked. This was key to public efficiency."
Im from a tropical country and houses are built with consideration for airflow, such as concrete walls with no insulation, gaps in the roof, etc. Also, days are shorter(no 8 pm daylight). American suburban homes are built with central AC in mind of course I dont expect people to know how to deal with heat without experience living in hot countries.
This is somewhat true for older (say, 1920s) American houses. There’s some consideration for airflow and making sure that the tree shade on the roof creates a strategic sun heat gradient.
Nearness to the equator is not the only relevant factor to the importance of AC. If you turn off the AC in many places in the USA in the summer, lots of people die.
Those places already have lots of people die from heat waves, and modern society still functions.
Note that the original comment didn’t say “modern society.” It said “modern life” and was very clearly describing the commenter’s ability to keep their own household running.
I didn't take "How much longer before modern life is no longer possible, I wonder..." to mean "how long until I'm forced to call in a specialist." The rest of their post is personal though, so I'm not confident in my interpretation that "modern society" would mean the same thing.
> Those places already have lots of people die from heat waves
AFAIK; the pieces where lots of people tend to die from heat waves in are the places where there isn't a regular annual need for AC.
AFAIK; the pieces where lots of people tend to die from heat waves in are the places where there isn't a regular annual need for AC.
Which, in the US, is Hawaii and some of the minor islands, and maybe parts of Alaska.
also Maine (in most years)
I knew a guy who lived in Maine before he moved to Nevada. He said the weather was 'not fit for man nor beast'
I don't know where that would refer to in the US. Illinois? Oklahoma? Missouri?
Modern life is in no real danger, though more of us than usual may find ourselves tested!
There are greater economic threats pushing people into these skills.
Personally, since I have them, I am happy to share with others during these times. Just good to know. And one never really can know when it all will matter.
There are greater economic threats pushing people into these skills.
Personally, since I have them, I am happy to share with others during these times. Just good to know. And one never really can know when it all will matter.
It's not like the supply chains just vanished. It's just a huge, slow moving machine that will take some time to catch up.
Depending on where you live much plumbing and electrical work can be done by the homeowners - sometimes a licensed tradesman is required to sign off before the inspector comes, other times not.
Either way and in any case it is worthwhile learning what is being done, even if only to make sure corners aren’t being cut.
Either way and in any case it is worthwhile learning what is being done, even if only to make sure corners aren’t being cut.
> sometimes a licensed tradesman is required to sign off before the inspector comes, other times not.
It's typical if this is the rule for a tradesman to refuse to sign off on work, or charge you a high fee to do so.
It's typical if this is the rule for a tradesman to refuse to sign off on work, or charge you a high fee to do so.
And this is because they are accepting liability for that work, I would charge a decent fee myself.
The amount of liability they are taking on is not that great. The fee is usually close to what the job would have cost.
In any case, it means "you can do it yourself but..." is pointless.
In any case, it means "you can do it yourself but..." is pointless.
What inspector? Nothing gets inspected unless you apply for a building permit, or have some kind of obvious major damage. If it's just regular repairs or minor renovations then in practice you can pretty much do whatever you want.
Yeah I was assuming a higher bar than simple repair (which should be done by all and sundry, even if you feel the need to hire someone to tell you you did it right)
If you’re learning to repair things for yourself then why would a license come into play?
It's illegal to do your own electrical and plumbing work for pretty sound reasons. Not that it matters. There is no shortage of local electricians and plumbers.
That varies quite a bit by location. In many areas, a homeowner can do their own repairs. In slightly fewer areas, they can do new installs. In any case, doing the work safely and correctly trumps having a license in importance.
> In any case, doing the work safely and correctly trumps having a license in importance.
Getting major work done without a license seems like a great idea until one tries to file a major claim with their homeowner’s insurance.
Getting major work done without a license seems like a great idea until one tries to file a major claim with their homeowner’s insurance.
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No it's not. In a lot of places if you're the home owner you can do your own everything.
Ok where I am you certainly can not do it yourself and if there is a fault which causes a fire or electrocution, you could be criminally liable.
Interesting; all that's required here is that the work be inspected by the city on completion. I can't imagine someone telling me what I can and can't repair in my home.
There is only one electrician I know of who doesn’t charge 2-3x to come to our exurban neighborhood. That’s because he lives in the area. Unfortunately, he’s moving away soon. So, at least here, there is a shortage of electricians.
That doesn't sound like a shortage, just sounds like you live far away from a city so it costs more for travel times.
Right; there is a premium you pay for living in an area with low density. The housing may be cheaper but services in general are a lot more expensive.
The shortage is already here. (Just got given a free several $k value upgrade to keep our business when we were going to cancel an install order because it wouldn’t be possible to get all the components for thr system we ordered until late fall; from checking around that delay isn’t uncommon right now.)
I thought one of the reasons companies like carrier exported jobs to other countries was so that there would be more efficient in the supply market and less bottlenecks in manufacturing.
Silly rabbit, they did it to maximize profit!
Where's the problem? More efficient manufacturing means fewer components sitting around in warehouses waiting to be used. Fewer products sitting on shelves. It means having smaller buffers. An interruption to manufacturing of connivent, such as a factory shutdown, will translate into hiccups down the line due to small(er) buffers.
It's actually not at all dissimilar to how many things in computers work.
It's actually not at all dissimilar to how many things in computers work.
I also don’t assume that manufacturing would have been more resilient during the pandemic if it had remained domestic, given the various public policy failures in this country over the last year: uncontrolled spread, laggard regulatory infrastructure, poorly designed labor incentives, etc.
Logistics in the country recovered fairly quickly from the various national disasters, so that's at least one less problem.
Well I can't wait until we offshore all Programming jobs, or have AI powerful enough to kick those spoiled overpaid Programmers to the curb? (This is happening. Good luck finding a Programming job after 40.)
Sometimes you want the talent close. Sometimes you want critical parts close. Sometimes you want your neighbor to have a job.
Until there's a working Basic Income; I prefer keeping most jobs/products close.
Sometimes you want the talent close. Sometimes you want critical parts close. Sometimes you want your neighbor to have a job.
Until there's a working Basic Income; I prefer keeping most jobs/products close.
Why just until then, if ever? Keep the money local.
As for programming jobs, I think most people who have been in the field for a while have seen plenty of examples of how offshoring doesn't work, and from what I've seen this is known in the c suite as well.
As for programming jobs, I think most people who have been in the field for a while have seen plenty of examples of how offshoring doesn't work, and from what I've seen this is known in the c suite as well.
The fundamental problem with offshoring is that you always want to keep important products in house. If the product isn't important you can offshore it but you can also just not do it.
Companies are already trying to flood the market with H1Bs to suppress wages and pushing people towards CS and STEM degrees in general. They don't need to do anything special, in 10 years the market will be flooded and you will be competing with someone who is willing to work 10+ hrs/day for half the wage.
Sounds like what the game dev market already is.
There are problems with the H-1B visa program but it's hardly flooding the market. Congress has held the quota stable for the past several years.
https://www.americanimmigrationcouncil.org/research/h1b-visa...
https://www.americanimmigrationcouncil.org/research/h1b-visa...
The problem is resilience. Our economy is now fragile, which is not great. And having no excess inventory doesn't mean having no inventory, since supply chain disruptions aren't necessarily immediate to recover from.
Toyota, which pioneered lean manufacturing, is currently laughing its way to the bank; it has a stockpile of semiconductors, since the 2011 Tohoku quake and tsunami exposed how fragile its supply chain for semiconductors was.
Toyota, which pioneered lean manufacturing, is currently laughing its way to the bank; it has a stockpile of semiconductors, since the 2011 Tohoku quake and tsunami exposed how fragile its supply chain for semiconductors was.
Sure, but that still is less efficient when things are working fine. Any time you tie up resources that you don't absolutely have to is a loss of efficiency.
And at the same time every order you're not filling because of an overzealously tight supply chain is a loss of business. Penny wise and pound foolish.
If it makes sense to stockpile for the company that pretty much invented lean manufacturing as we know it, it's not without merit.
If it makes sense to stockpile for the company that pretty much invented lean manufacturing as we know it, it's not without merit.
Cars are very high cost items. They probably have substantial margins on them. On the other hand, a product that has very low margins is going to find it much more difficult to stockpile.
In this case isn't it needed to consider efficiency over the short and longer term? And for the long-term efficiency one of the parameters would be resilience to shocks, which affects the short-term efficiency (more inventory juggling) but is healthier over a longer span of time.
Short-term efficiency is there all the time. Shocks are not. If the space you're competing in has enough competition then the margins will be low. The companies that focus on short-term efficiency could end up outcompeting the companies that keep large buffers.
Once you've eliminated all your bottlenecks, it means that every step is a bottleneck.
I know this is tongue in cheek, but they're exporting jobs and manufacturing to duck taxes. Not necessarily high wages -- sometimes it is that -- but it is usually just the large cost of keeping inventory.
I don't know if a global pandemic is really something that can be planned around.
For anyone who's built a PC before and happens to find themselves without AC, buy a few window fans and you'll find that you can create a consistent airflow in your room/house the same way you make airflow in a PC case. If you're in a room that generates heat, blow air out. Otherwise pull air from outside a larger/two fan(s) and blow air out with a smaller fan.
Also, using aggressive power saving is quite effective when sharing a room with a PC. A human gives off about 50 W of heat when sitting somewhere. PCs can easily consume multiple times as much, a loaded gaming PC is the equivalent of a half a dozen people sitting in! No surprise it gets hot.
In our area evaporative coolers are like magic. They use almost no energy but can bring down the room temp more than 15F.
Labor and material shortages for domestic production, container ship traffic jams for imports.
It's a bit crazy to say the least.
I went to the WalMart by my house, today, to replace a blender who's motor failed. I realized as I passed the bike section, now 1/8th full, that "hey, (awful) bikes are back!". They're not, but there were a whole ten of them which is ten more than I've seen all year.
Hop over to the blenders and they have fifteen models on display but boxes for 5 of them.
Only self-service check-out is open, and only half of them, the line extends ten people past the "impulse buys" in the six "any number of items" self-checkout lanes. Two members of front-end staff look like they're ready to burn the place down, customers have stopped swearing under their breath and are now engaged in outright, obvious, complaining. I roll up to the chaos with my less-than-desired blender and realize I might as well just wait for shipping because it's 10:00 PM, this is an hour long line, and I'm not going to be the reason these poor employees have to stay late since the 24-hour WalMart hasn't been open past 11:00 PM since last year.
It's a lot of griping, and I'm really not upset -- I got a nice excuse to hop on my one-wheel in the dark and avoided spending some money on something I don't need "today"; a really minor inconvenience, I just miss the good old days of ... 2019? :)
I went to the WalMart by my house, today, to replace a blender who's motor failed. I realized as I passed the bike section, now 1/8th full, that "hey, (awful) bikes are back!". They're not, but there were a whole ten of them which is ten more than I've seen all year.
Hop over to the blenders and they have fifteen models on display but boxes for 5 of them.
Only self-service check-out is open, and only half of them, the line extends ten people past the "impulse buys" in the six "any number of items" self-checkout lanes. Two members of front-end staff look like they're ready to burn the place down, customers have stopped swearing under their breath and are now engaged in outright, obvious, complaining. I roll up to the chaos with my less-than-desired blender and realize I might as well just wait for shipping because it's 10:00 PM, this is an hour long line, and I'm not going to be the reason these poor employees have to stay late since the 24-hour WalMart hasn't been open past 11:00 PM since last year.
It's a lot of griping, and I'm really not upset -- I got a nice excuse to hop on my one-wheel in the dark and avoided spending some money on something I don't need "today"; a really minor inconvenience, I just miss the good old days of ... 2019? :)
There are shortages of pretty much all appliances at this point. Less desirable models are still generally available.
As an example, I heard there’s a 1,000,000 unit backorder of market-leader Bosch’s dishwashers.
As an example, I heard there’s a 1,000,000 unit backorder of market-leader Bosch’s dishwashers.
They were sold out last year in the middle of the pandemic. Took over a month to get mine ordered and I had to order a more expensive version, installer said he’s was fully booked with dishwasher installs from people upgrading due to being home more and cooking every meal.
Freezers were also sold out early in the pandemic as people stockpiled frozen food.
Air conditioners are sold out every summer when you would really need one.
[deleted]
I'd suggest people research whole house fans. They mount in the ceiling on your top level and suck air from your open windows into the attic.
We had one growing up in Iowa. Despite upper 70's to mid 80's much of May, June, and July, we were able to avoid running the air conditioner by sucking in the 50-60 degree air overnight and closing up the windows during the day. By late July and August, it was time to use the air conditioner.
The fans can typically rotate all the air in a house every handful of minutes, and the breeze helps sweat evaporate, immensely helping comfort. Their cost is typically a couple hundred dollars, but you can spend up to ~1,200 for a quiet, high volume model.
I'm looking to install one in my house. The downside I'm trying to work through is, should a fire break out, I want the fan to turn off. I haven't found a COTS system to do this and integrate with the hardwired smoke detectors.
We had one growing up in Iowa. Despite upper 70's to mid 80's much of May, June, and July, we were able to avoid running the air conditioner by sucking in the 50-60 degree air overnight and closing up the windows during the day. By late July and August, it was time to use the air conditioner.
The fans can typically rotate all the air in a house every handful of minutes, and the breeze helps sweat evaporate, immensely helping comfort. Their cost is typically a couple hundred dollars, but you can spend up to ~1,200 for a quiet, high volume model.
I'm looking to install one in my house. The downside I'm trying to work through is, should a fire break out, I want the fan to turn off. I haven't found a COTS system to do this and integrate with the hardwired smoke detectors.
Another down side is, you don't want to do this if you're in the swampy south. You'll bring in all the humidity and that will cause all sorts of problems. Also, you bring in any dust, pollen, etc that may be lingering.
Putting air purifiers by windows could probably help. Might need a couple though. It might work with just one big though, for instance I know there's huge tube shaped ones with a ton of surface area to catch stuff in HEPA- or electro static filters.
To counter matt_the_bass's example, I live in the NE US, I have always used the method (in this case, window upstairs open, window downstairs open, natural draft cooling the house by dragging the air through), but there is absolutely no level of filtering that will stop all pollutants and allergens from entering the house as long as you are not filtering 100% of the air.
Last time I noticed, nobody makes a window-sized AC-esque filter that works efficiently down to PM2.5 levels... and doing so would also eliminate said window being a window.
Last time I noticed, nobody makes a window-sized AC-esque filter that works efficiently down to PM2.5 levels... and doing so would also eliminate said window being a window.
This works great for me in NE USA. We have two large filters. Usually keep one upstairs and one downstairs. They make a noticeable difference. But they were about $250 each.
Interesting. So essentially the same as having fans in your windows, but without all of the noise (since one powerful fan in a central location is pulling air out of the house)
Yep. Growing up it was a 36" direct drive motor attached to the fan blades. It was a louder unit, but that was fine since it was in the back of the house away from bedrooms. There are quieter units available which are driven by DC motors with additional sound isolation features available, such as https://quietcoolsystems.com/whole-house-fan/. Probably the direction I will go when I install one.
You’ll need the equivalent of this for your brand of smoke detectors:
https://support.firstalert.com/s/article/rm4
And, depending on whether your fan is in spec for the built in relay, you may need a larger relay to switch it.
https://support.firstalert.com/s/article/rm4
And, depending on whether your fan is in spec for the built in relay, you may need a larger relay to switch it.
Dear god, I thought that fan idea sounded awesome until you mentioned the fire concern. Good thing you’re smart and thought of that.
Life involves risk. We also suck at evaluating risk, and statistics are helpful to a point. You only have one life to live. Life insurance companies spread the everyday risks across many people.
Fires spread much faster than they used to because of changes in building materials [1]. I figure if I can find a way to shut it off automatically, it'll buy me 30+ seconds, which is a big deal.
I found [2] awhile back, which is what I want, but I'd happily pay for a COTS solution.
[1] https://youtu.be/aDNPhq5ggoE
[2] https://hackaday.io/project/165689-prevent-accidental-3d-pri...
Fires spread much faster than they used to because of changes in building materials [1]. I figure if I can find a way to shut it off automatically, it'll buy me 30+ seconds, which is a big deal.
I found [2] awhile back, which is what I want, but I'd happily pay for a COTS solution.
[1] https://youtu.be/aDNPhq5ggoE
[2] https://hackaday.io/project/165689-prevent-accidental-3d-pri...
Looks like [1] addresses the furnishings in the room, not the building materials. Modern drywall, for example, takes 30 minutes to burn. And fire rated drywall takes an hour.
Brick and mortar takes a lot longer than 30 minutes to burn.
Yet has decidedly more 'fall on my head in event of an earthquake' potential than stick building, in my part of the world. Different building materials have trade offs.
Plus, how many residences (other than chic converted factory lofts I guess) even have bare brick and mortar interiors?
Plus, how many residences (other than chic converted factory lofts I guess) even have bare brick and mortar interiors?
This was a pleasant surprise for me to read. My father installed one in our home in Ohio in the late 60’s and it worked great.
My dad was ahead of his time. He installed a geothermal heat pump to heat the house with heat from our 200’ well, too.
Thanks for a pleasant reminder!
My dad was ahead of his time. He installed a geothermal heat pump to heat the house with heat from our 200’ well, too.
Thanks for a pleasant reminder!
There’s also radon to consider… yikes!
Radon is particularly prevalent in Iowa. A completely closed up house is the worst thing for it!
My dad spent a few years thinking through details about the house before building. Passive radon mitigation was built in (active added later), air exchanger would bring in new air without losing all the heat/cold of the conditioned air, radiant floor heating in the basement, ~24" of blown in insulation in the attic, 6" walls for additional insulation, 24" eves give a bit more shade around the house.
My dad spent a few years thinking through details about the house before building. Passive radon mitigation was built in (active added later), air exchanger would bring in new air without losing all the heat/cold of the conditioned air, radiant floor heating in the basement, ~24" of blown in insulation in the attic, 6" walls for additional insulation, 24" eves give a bit more shade around the house.
Best treatment of radon is a lot of fresh air exchange. It's what these fans do well.
The fan wouldn’t be exchanging fresh air, it would be drawing it up from the ground. Radon gas is a product of decaying uranium underground. It usually gets into homes due to the “stack effect” where heated indoor air rises (in winter) and draws the gas up through the foundation. The parent commenter seems to be proposing a mechanism to do this in summer as well, just using a fan instead.
You open the windows in the house when running the whole house fan.
When we installed the fan, the documentation mentioned failure to open 9 square feet or more of outside doors/windows could result in a window breaking from the negative pressure.
When we installed the fan, the documentation mentioned failure to open 9 square feet or more of outside doors/windows could result in a window breaking from the negative pressure.
We have a radon meter in the house. Even just a single box fan in Window, sucking air out of the house makes and ENORMOUS difference. We're talking <1 ppm, whereas before it could get up to ~12ppm on bad days. We bought a radon removal system when we bought the house, it it doesn't seem to work nearly as well as simply venting the house.
Like someone else said, you open the windows.
A negative pressure house is bad for more than just radon. It can cause certain appliances to vent bad stuff into the house too.
A negative pressure house is bad for more than just radon. It can cause certain appliances to vent bad stuff into the house too.
Would you eventually suck them dry of bad stuff? Would putting appliances in a negative pressure environment before selling them to consumers be good?
"bad stuff" in this case is combustion gas from natural gas appliances, sewer gas from sucking the water out of toilets, etc. So no, there's no end to the "bad stuff" they generate.
Separately, offgassing is an issue for sofas and mattresses, anything made of particle board as well, but if you put them in a low pressure environment, it doesn't drastically accelerate offgassing. If they offgas formaldehyde, they're going to keep doing it after the low pressure period has ended, so better to avoid those materials altogether.
Separately, offgassing is an issue for sofas and mattresses, anything made of particle board as well, but if you put them in a low pressure environment, it doesn't drastically accelerate offgassing. If they offgas formaldehyde, they're going to keep doing it after the low pressure period has ended, so better to avoid those materials altogether.
Yes. First get a sensor so you can track it, radon can change quite a bit over time. I bought two from airthings.com. They support IOS, Android, and even have an graphana plugin (direct, not requiring upload to a cloud first). They track temp, humidity, VOCs, radon, CO2, and something else I can't remember. They have pretty incredible bluetooth range, it's slow, but I can get an update of both sensors from anywhere in my 3 story house. I'm used to bluetooth only sometimes working when on the same floor.
After mapping out my house we saw numbers as high as 15, 4.0 is the recommended mitigation threshold in the USA, 2.6 for the EU.
After talking to a company they recommended sealing our sump pump area, and then installing a fan that sucked air from under our foundation. Our readings dropped from 15 to 0.5, and stayed there. I do wonder how long the sump pump sealant will last, but I have the airthings to watch.
So sure, open up the windows when you can, but I'm glad I can close the windows when it's smokey or cold and still have low radon levels.
After mapping out my house we saw numbers as high as 15, 4.0 is the recommended mitigation threshold in the USA, 2.6 for the EU.
After talking to a company they recommended sealing our sump pump area, and then installing a fan that sucked air from under our foundation. Our readings dropped from 15 to 0.5, and stayed there. I do wonder how long the sump pump sealant will last, but I have the airthings to watch.
So sure, open up the windows when you can, but I'm glad I can close the windows when it's smokey or cold and still have low radon levels.
We had one of those in the house when I was a kid; we called it the attic fan. It was noisy and generated a noticeable breeze in the house, but we had it for warm days and window a/c units on hot day, until dad got central air installed when I was in high school.
You need a smoke detector that provides dry contacts/relay output and some minimal wiring.
Thank you, I was coming up short on terminology since this is outside my normal field! It looks like there are some relays directly from Kidee which might integrate directly with the hardwired smoke detectors. I'll definitely do some more research.
Hmmm interesting. I have camelcamelcamel alerts for a couple air conditioners but they have never gotten down to the price I set. I guess that explains it. Maybe another summer of a fan and wet t-shirts for me.
This happened to my friend last week. It’s when I started contemplating how bad this could get in the winter if furnaces go out and can’t be turned on…
Furnaces have an emergency override, you should learn how it works and how to use it.
I'm disappointed how many don't try to cross-ventilate, spin fans, or to use blackouts before thinking of AC cooling.
Here, have a read: http://archive.kuow.org/post/modern-seattle-building-doesn-t...
Here, have a read: http://archive.kuow.org/post/modern-seattle-building-doesn-t...
What the article describes won't work in most houses as it's designed around a thermal chimney. It doesn't work with high temperatures, even at only 85 degrees it's 78 inside. They note that building is effectively unusable during heat waves and the hottest part of the day. And the article ends by noting that the problems are continuing to get worse as the temperatures increase.
AC cooling has massive advantages, there are solid reasons why every building should have heat pumps. Doing some of these techniques can reduce the load on HVAC systems, but eliminating them entirely is a bit silly.
AC cooling has massive advantages, there are solid reasons why every building should have heat pumps. Doing some of these techniques can reduce the load on HVAC systems, but eliminating them entirely is a bit silly.
> but eliminating them entirely is a bit silly.
What's silly is the fixed working time and not allowing and training our bodies and ourselves to accommodate the temperature. There's a reason for siesta, and a reason for Mediterranean people being active at night.
What's silly is the fixed working time and not allowing and training our bodies and ourselves to accommodate the temperature. There's a reason for siesta, and a reason for Mediterranean people being active at night.
Yes and HVAC prevents people from dying due to heat waves. It's been an increasing problem in the Mediterranean region because of climate change. HVAC is needed more in those areas than ever before. I can't imagine you're seriously arguing against HVAC and it's more an argument that we need to build more efficient houses and commercial structures so HVAC works more effectively.
I have a friend who owns an HVAC shop. Equipment has been on multi-month lead times since covid started. Her company is basically only doing installs right now because they can order the equipment well ahead of time and plan the installs. They haven’t been able to get adequate parts to do break-fix or maintenance service for a while so she just stopped doing it.
I am currently working with two South Asian air conditioner/fridge manufacturers on electronics projects, and they have whopping load of unsold inventory. Shout out if you have any commercial interest.