4 ms·

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 growin

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.

cyberlurker 5y ago
Dear god, I thought that fan idea sounded awesome until you mentioned the fire concern. Good thing you’re smart and thought of that.
- DavidPeiffer 5y ago
  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 https://youtu.be/aDNPhq5ggoE [2] https://hackaday.io/project/165689-prevent-accidental-3d-printer-fires https://hackaday.io/project/165689-prevent-accidental-3d-pri...
  - fpgaminer 5y ago
    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.
    - formerly_proven 5y ago
      Brick and mortar takes a lot longer than 30 minutes to burn.
      - Arrath 5y ago
        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?
jes 5y ago
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!
goodells 5y ago
There’s also radon to consider… yikes!
- throwawayboise 5y ago
  Best treatment of radon is a lot of fresh air exchange. It's what these fans do well.
  - goodells 5y ago
    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.
    - DavidPeiffer 5y ago
      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.
    - bcrosby95 5y ago
      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.
      - im3w1l 5y ago
        Would you eventually suck them dry of bad stuff? Would putting appliances in a negative pressure environment before selling them to consumers be good?
        5y ago
cratermoon 5y ago
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.
c_o_n_v_e_x 5y ago
You need a smoke detector that provides dry contacts/relay output and some minimal wiring.
- DavidPeiffer 5y ago
  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.
phendrenad2 5y ago
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)
- DavidPeiffer 5y ago
  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/ https://quietcoolsystems.com/whole-house-fan/. Probably the direction I will go when I install one.
HumblyTossed 5y ago
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.
- pastrami_panda 5y ago
  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.
  - matt_the_bass 5y ago
    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.
  - DiabloD3 5y ago
    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.
amluto 5y ago
You’ll need the equivalent of this for your brand of smoke detectors: https://support.firstalert.com/s/article/rm4 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.

cyberlurker 5y ago

Dear god, I thought that fan idea sounded awesome until you mentioned the fire concern. Good thing you’re smart and thought of that.

DavidPeiffer 5y ago
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 https://youtu.be/aDNPhq5ggoE [2] https://hackaday.io/project/165689-prevent-accidental-3d-printer-fires https://hackaday.io/project/165689-prevent-accidental-3d-pri...
- fpgaminer 5y ago
  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.
  - formerly_proven 5y ago
    Brick and mortar takes a lot longer than 30 minutes to burn.
    - Arrath 5y ago
      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?

jes 5y ago

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!

goodells 5y ago

There’s also radon to consider… yikes!

throwawayboise 5y ago
Best treatment of radon is a lot of fresh air exchange. It's what these fans do well.
- goodells 5y ago
  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.
  - DavidPeiffer 5y ago
    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.
  - bcrosby95 5y ago
    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.
    - im3w1l 5y ago
      Would you eventually suck them dry of bad stuff? Would putting appliances in a negative pressure environment before selling them to consumers be good?
      - 5y ago

cratermoon 5y ago

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.

c_o_n_v_e_x 5y ago

You need a smoke detector that provides dry contacts/relay output and some minimal wiring.

DavidPeiffer 5y ago
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.

phendrenad2 5y ago

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)

DavidPeiffer 5y ago
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/ https://quietcoolsystems.com/whole-house-fan/. Probably the direction I will go when I install one.

HumblyTossed 5y ago

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.

pastrami_panda 5y ago
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.
- matt_the_bass 5y ago
  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.
- DiabloD3 5y ago
  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.

amluto 5y ago

You’ll need the equivalent of this for your brand of smoke detectors: https://support.firstalert.com/s/article/rm4 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.