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Woah, this is pretty scary. Thank you for sharing. How did you know it was mold that was in the air? Is there some sort of test kit that you can buy to test for

Woah, this is pretty scary. Thank you for sharing. How did you know it was mold that was in the air? Is there some sort of test kit that you can buy to test for this. Mold is pretty hard to detect because you can't really see it because it typically hides between the walls. Any advice appreciated.

the_clarence 8y ago
You can notice black spots in your bathroom or other places where steam doesn't escape properly. I noticed it on my mattress also. I don't think I have any health issues because of that, it was 5 years ago, but it was rough.
- marco1 8y ago
  Mold is not always black, is it? It can have other colors as well, e.g. yellow.
sgc 8y ago
By the time it is a health issue, it is usually visible. There is some air passage from within the walls to the living space, but not nearly as much impact as the visible mold on walls, furniture, etc. Sauce: Get paid to test sometimes.
onetimemanytime 8y ago
Mold needs lack of ventilation /dampness. You see the dark spots (maybe that's too late?) and IMO nothing substitutes air flow, when possible. Even in winter, one needs to open windows and let the air flow freely at least for a while.
adinobro 8y ago
I know there is mould in my house. We do three things to deal with it: 1. Air Filter (more for pollution but it helps with mould) 2. Dehumidifier which we leave on 24/7 basically for the mould. This is the big one. 3. Wash any mould with vinegar to change the PH after it is wiped off to prevent it from growing back. The mould is still there but the dry air stops it from growing and sporing which is what makes you stick. If humidity creeps up the mould will grow again. Be aware that mould is virtually everywhere and is only harmful if there is enough of it around sporing or if you touch it.
- a012 8y ago
  Dehumidifiers are expensive in power consumption, I don't know which model is more effectively. I'm living in SEA, and get humidity level to 50% 24/7 in my studio equally to double my monthly electricity bill.
  - Cthulhu_ 8y ago
    I don't know if these are effective, but in my country we have passive dehumidifiers which are basically containers with a load of salt or something like that which draws the moisture out of the air. Good enough to keep caravans in storage mold free. Probably not good enough for e.g. living rooms or actually moist locations, but maybe it scales up. Of course, you'd then need a lot of salt or whatever the stuff is.
    - majewsky 8y ago
      I used the passive variant that you explained in my previous apartment and while it may be effective at keeping humidity down, it's not very effective in bringing a high humidity down. I got an electric dehumidifier and it's drastically more efficient. It pulls over two liters of water per day out of the air if the air is sufficiently humid. I've since moved, so I don't use it routinely anymore, but I still have it and occasionally use it to speed up the drying of clothes on a drying rack.
      - a012 8y ago
        My dehumidifier draws 4l per 8 hours.
        detritus 8y ago
        May I ask what model it is, please?
        a012 8y ago
        It's https://www.sharp.com.hk/en/model/762-hd-plasmacluster-dehumidifier https://www.sharp.com.hk/en/model/762-hd-plasmacluster-dehum...
fyfy18 8y ago
The CDC has some recommendations on it (yes you can have mold tested to see if it's dangerous): https://www.cdc.gov/mold/stachy.htm https://www.cdc.gov/mold/stachy.htm I'm not really sure about keeping the humidity below 50% though. The UK and most of Northern Europe has rather high humidity in the winter. It commonly reaches 80-90 RH outside, so you'd have to heat your house to 25c/77F to bring the humidity below 50%.
- toxik 8y ago
  Northern Europe gets really cold, so while RH may be high, it’s not moist at all. People get dry skin in the winter.
  - chupasaurus 8y ago
    Northern Scandinavia and west of Urals (I live here) have moist winters (70+% RH most of the time). Skin would dry anyway because water evaporation rate is proportional to a pressure (hence temperature) difference and convection makes a constant supply of fresh unsaturated air.
    - zaarn 8y ago
      Relative Humidity is relative to temperature. Cold air can simply hold less water overall, at 20C it can easily hold double as much water as it can at 0C. There being a pressure difference is nonsense, you can get the same air pressure in the winter as in summer (though it tends to go on the Low side more often). What you probably mean is the vapor pressure, ie the natural pressure the liquid wants to be at in a closed container, though while it is largely depdenent on temperature, it does so in a linear/positive way, so at lower temperature, water will evaporate less (otherwise ice would more easily sublimate). Once you go below zero a water content of a few grams can easily hit 100% RH which would barely manage 5% or less at 30C.
      - logfromblammo 8y ago
        I think the relevant pressures are the vapor pressure of liquid water, the atmospheric pressure, and the partial pressure of gaseous H2O at the gas-liquid interface. If you can blow dry air over its surface, you can evaporate liquid water (or sublimate water ice) even when the relative humidity is 100%. You can think of air as a gaseous solution, and its water vapor content like table salt in aqueous solution. Temperature affects the solubility, and if the solution is saturated, no more can dissolve. You can still dissolve salt crystals sitting in a saturated cold saltwater solution by squirting warm freshwater onto the bottom of the container. If that then mixes with the rest of the solution, and everything cools down again, that dissolved salt can then precipitate out somewhere else (like rain), or form a suspension of tiny crystals (like fog or clouds). The solubility of H2O vapor in atmospheric gas increases with temperature. But you can also do something with a gaseous solvent that you can't easily do with a liquid solvent, which is to change the pressure. Higher pressure lowers the solubility of water in air, but to a far lesser extent than a decrease in temperature. Even though the vapor pressure is dependent only on temperature, evaporation occurs whenever the vapor pressure exceeds the partial pressure of H2O at the interface. Increasing the overall air pressure also increases the partial pressure of H2O vapor by a proportional amount, so inhibits further evaporation. But water vapor is also less dense than N2, O2, and most other atmospheric gases, so the means of measuring pressures gets complicated. When you involve wind, and stratified airflows, it gets even more complicated. The air blowing across water or water ice could have been previously warmed by the ground just enough to evaporate more water, then get pushed higher by an angled snowbank into colder, saturated air, and it will then dump the excess water as small ice crystals. A solid block of ice can then become "rotten" as a snowdrift forms downwind of it. The overall average temperature may say that ice should stay frozen, but the wind can still carry a tiny bit of water vapor at a time, thanks to local fluctuations, and with enough volume of air to move it, that ice will drift.
marco1 8y ago
You can buy test kits that you expose to your rooms’ air for some time, and then a lab will grow the mold inside the Petri dishes to “amplify” what has been collected in your home. That may be expensive, though, and not easily available everywhere, and perhaps even prone to contamination “in transit”?

the_clarence 8y ago

You can notice black spots in your bathroom or other places where steam doesn't escape properly. I noticed it on my mattress also. I don't think I have any health issues because of that, it was 5 years ago, but it was rough.

marco1 8y ago
Mold is not always black, is it? It can have other colors as well, e.g. yellow.

sgc 8y ago

By the time it is a health issue, it is usually visible. There is some air passage from within the walls to the living space, but not nearly as much impact as the visible mold on walls, furniture, etc. Sauce: Get paid to test sometimes.

onetimemanytime 8y ago

Mold needs lack of ventilation /dampness. You see the dark spots (maybe that's too late?) and IMO nothing substitutes air flow, when possible. Even in winter, one needs to open windows and let the air flow freely at least for a while.

adinobro 8y ago

I know there is mould in my house. We do three things to deal with it: 1. Air Filter (more for pollution but it helps with mould) 2. Dehumidifier which we leave on 24/7 basically for the mould. This is the big one. 3. Wash any mould with vinegar to change the PH after it is wiped off to prevent it from growing back. The mould is still there but the dry air stops it from growing and sporing which is what makes you stick. If humidity creeps up the mould will grow again. Be aware that mould is virtually everywhere and is only harmful if there is enough of it around sporing or if you touch it.

a012 8y ago
Dehumidifiers are expensive in power consumption, I don't know which model is more effectively. I'm living in SEA, and get humidity level to 50% 24/7 in my studio equally to double my monthly electricity bill.
- Cthulhu_ 8y ago
  I don't know if these are effective, but in my country we have passive dehumidifiers which are basically containers with a load of salt or something like that which draws the moisture out of the air. Good enough to keep caravans in storage mold free. Probably not good enough for e.g. living rooms or actually moist locations, but maybe it scales up. Of course, you'd then need a lot of salt or whatever the stuff is.
  - majewsky 8y ago
    I used the passive variant that you explained in my previous apartment and while it may be effective at keeping humidity down, it's not very effective in bringing a high humidity down. I got an electric dehumidifier and it's drastically more efficient. It pulls over two liters of water per day out of the air if the air is sufficiently humid. I've since moved, so I don't use it routinely anymore, but I still have it and occasionally use it to speed up the drying of clothes on a drying rack.
    - a012 8y ago
      My dehumidifier draws 4l per 8 hours.
      - detritus 8y ago
        May I ask what model it is, please?
        a012 8y ago
        It's https://www.sharp.com.hk/en/model/762-hd-plasmacluster-dehumidifier https://www.sharp.com.hk/en/model/762-hd-plasmacluster-dehum...

fyfy18 8y ago

The CDC has some recommendations on it (yes you can have mold tested to see if it's dangerous): https://www.cdc.gov/mold/stachy.htm https://www.cdc.gov/mold/stachy.htm I'm not really sure about keeping the humidity below 50% though. The UK and most of Northern Europe has rather high humidity in the winter. It commonly reaches 80-90 RH outside, so you'd have to heat your house to 25c/77F to bring the humidity below 50%.

toxik 8y ago
Northern Europe gets really cold, so while RH may be high, it’s not moist at all. People get dry skin in the winter.
- chupasaurus 8y ago
  Northern Scandinavia and west of Urals (I live here) have moist winters (70+% RH most of the time). Skin would dry anyway because water evaporation rate is proportional to a pressure (hence temperature) difference and convection makes a constant supply of fresh unsaturated air.
  - zaarn 8y ago
    Relative Humidity is relative to temperature. Cold air can simply hold less water overall, at 20C it can easily hold double as much water as it can at 0C. There being a pressure difference is nonsense, you can get the same air pressure in the winter as in summer (though it tends to go on the Low side more often). What you probably mean is the vapor pressure, ie the natural pressure the liquid wants to be at in a closed container, though while it is largely depdenent on temperature, it does so in a linear/positive way, so at lower temperature, water will evaporate less (otherwise ice would more easily sublimate). Once you go below zero a water content of a few grams can easily hit 100% RH which would barely manage 5% or less at 30C.
    - logfromblammo 8y ago
      I think the relevant pressures are the vapor pressure of liquid water, the atmospheric pressure, and the partial pressure of gaseous H2O at the gas-liquid interface. If you can blow dry air over its surface, you can evaporate liquid water (or sublimate water ice) even when the relative humidity is 100%. You can think of air as a gaseous solution, and its water vapor content like table salt in aqueous solution. Temperature affects the solubility, and if the solution is saturated, no more can dissolve. You can still dissolve salt crystals sitting in a saturated cold saltwater solution by squirting warm freshwater onto the bottom of the container. If that then mixes with the rest of the solution, and everything cools down again, that dissolved salt can then precipitate out somewhere else (like rain), or form a suspension of tiny crystals (like fog or clouds). The solubility of H2O vapor in atmospheric gas increases with temperature. But you can also do something with a gaseous solvent that you can't easily do with a liquid solvent, which is to change the pressure. Higher pressure lowers the solubility of water in air, but to a far lesser extent than a decrease in temperature. Even though the vapor pressure is dependent only on temperature, evaporation occurs whenever the vapor pressure exceeds the partial pressure of H2O at the interface. Increasing the overall air pressure also increases the partial pressure of H2O vapor by a proportional amount, so inhibits further evaporation. But water vapor is also less dense than N2, O2, and most other atmospheric gases, so the means of measuring pressures gets complicated. When you involve wind, and stratified airflows, it gets even more complicated. The air blowing across water or water ice could have been previously warmed by the ground just enough to evaporate more water, then get pushed higher by an angled snowbank into colder, saturated air, and it will then dump the excess water as small ice crystals. A solid block of ice can then become "rotten" as a snowdrift forms downwind of it. The overall average temperature may say that ice should stay frozen, but the wind can still carry a tiny bit of water vapor at a time, thanks to local fluctuations, and with enough volume of air to move it, that ice will drift.

marco1 8y ago

You can buy test kits that you expose to your rooms’ air for some time, and then a lab will grow the mold inside the Petri dishes to “amplify” what has been collected in your home. That may be expensive, though, and not easily available everywhere, and perhaps even prone to contamination “in transit”?