5 ms·

That kind of depends on where you live. And this can be combined with air filtration.

by 20after4 2y ago

PittleyDunkin 2y ago
Definitely in some places, but is there a region where outdoor air is so clean you don't need this device?
- viraptor 2y ago
  Almost any place away from cities. I've got AQI <30, down to 5 or so, almost the whole year for example. (Apart from during an occasional bushfire) Cities and industrial sites are the exception with bad air quality, not the default.
  - cyberax 2y ago
    That depends, really. If you have an inversion layer going, you can get pretty poor air quality in lots of locations because people use crappy wood-fired stoves that produce a lot of particulates.
    - 20after4 2y ago
      That does happen occasionally where I live, last night for example. But it's only a single digit number of days out of a year. The rest of the time air quality is very good.
  - vineyardmike 2y ago
    To be fair, "cities are the exception with bad air" neglects the reality that cities are the default for where people live. So the "air near people" is generally city air. That said, I live in SF and my AQI is usually <50. Not as great as 5, but we sometimes get down to single-digits. Cities don't have to have bad air.
- amluto 2y ago
  The filtration is icing on the cake. You want an HRV or ERV in any location where you want heating or cooling for any non-negligible portion of the year so that you can have energy efficient fresh air.
- dzhiurgis 2y ago
  I live in small town on NZ coast. Air is very clean. Mosquitos and neighbor's wood burners don't care. ERV is top 3 item in my house (other than induction cooktop and Japanese toilets).
  - willvarfar 2y ago
    (ok nodding to ERV and induction cooktops, but what is a japanese toilet and why are they better? Haven't heard of them from grand-designs and those kind of youtubers)
    - kla-s 2y ago
      - auto lid open and close - heated seat - water jet to clean buttocks with subsequent warm air blower - relaxing music speaker (to drown out your defecating sounds and get you started) just some ideas what some (public)/most (nice home) japanese toilets offer, which might be hard to come by anywhere else
      - ajolly 2y ago
        This is the first I've heard of auto lid open and close!
        dzhiurgis 2y ago
        Only available on expensive models. Seat heating and washing are the key features.
      - dzhiurgis 2y ago
        > hard to come by They are $200-300 online. Not Toto quality, but plenty good enough.
- macrolime 2y ago
  The ERV itself is for removing CO2, not dust. Especially in cold climates where houses are built to be as air-tight as possible, these are a necessity. Even if you lived in a forest cabin you'd want filters to prevent too much dust and pollen. I've got a dual filter on mine, HEPA and activated carbon filter. The HEPA filter removes dust and pollen. I've found that if I don't use the carbon filter I get higher than recommended levels of NOx.
  - open_erv2 2y ago
    You can add a filter to the TW4, there is an adapter/kit. It's a hepa filter from a car cabin filter system design. You rarely need both anti pollen and also ERV, so you would take the heat exchanger out and just use the filter and fan. As for dust, I recommend a good pc fan filter based appliance, not putting the filter in the flow path of the ERV.
- jeroenhd 2y ago
  Most people here just open a window when they want to air out a room. That said, that does waste a lot of energy when heating/cooling your home on cold/hot days, so ERVs and HRVs are used to get the clean air in without exchanging heat with the outside world too much. They're quite cheap and effective compared to just running normal ventilation.
block_dagger 2y ago
I live near a ten lane highway. I prefer to keep the outdoor air out, and the indoor air filtered. I could see this being very useful for other dwellings though.
- amluto 2y ago
  You are either already failing to keep outdoor air out or you are getting too little ventilation. What you want is something like this device with the H13 filter option. Maybe that plus carbon.
- positr0n 2y ago
  Think of it this way, since you aren't dying of asphyxiation when you sleep at night, you're already getting some air exchange with the outside air. With an ERV you can control how much air you get, and put whatever filter you want in between the outside air and your room. In fact the fancier systems will let you overpressure your house by running the fan pushing in slightly higher than the air pushing out, ensure air only leaks out of your house not in.

That kind of depends on where you live. And this can be combined with air filtration.

PittleyDunkin 2y ago

Definitely in some places, but is there a region where outdoor air is so clean you don't need this device?

viraptor 2y ago
Almost any place away from cities. I've got AQI <30, down to 5 or so, almost the whole year for example. (Apart from during an occasional bushfire) Cities and industrial sites are the exception with bad air quality, not the default.
- cyberax 2y ago
  That depends, really. If you have an inversion layer going, you can get pretty poor air quality in lots of locations because people use crappy wood-fired stoves that produce a lot of particulates.
  - 20after4 2y ago
    That does happen occasionally where I live, last night for example. But it's only a single digit number of days out of a year. The rest of the time air quality is very good.
- vineyardmike 2y ago
  To be fair, "cities are the exception with bad air" neglects the reality that cities are the default for where people live. So the "air near people" is generally city air. That said, I live in SF and my AQI is usually <50. Not as great as 5, but we sometimes get down to single-digits. Cities don't have to have bad air.
amluto 2y ago
The filtration is icing on the cake. You want an HRV or ERV in any location where you want heating or cooling for any non-negligible portion of the year so that you can have energy efficient fresh air.
dzhiurgis 2y ago
I live in small town on NZ coast. Air is very clean. Mosquitos and neighbor's wood burners don't care. ERV is top 3 item in my house (other than induction cooktop and Japanese toilets).
- willvarfar 2y ago
  (ok nodding to ERV and induction cooktops, but what is a japanese toilet and why are they better? Haven't heard of them from grand-designs and those kind of youtubers)
  - kla-s 2y ago
    - auto lid open and close - heated seat - water jet to clean buttocks with subsequent warm air blower - relaxing music speaker (to drown out your defecating sounds and get you started) just some ideas what some (public)/most (nice home) japanese toilets offer, which might be hard to come by anywhere else
    - ajolly 2y ago
      This is the first I've heard of auto lid open and close!
      - dzhiurgis 2y ago
        Only available on expensive models. Seat heating and washing are the key features.
    - dzhiurgis 2y ago
      > hard to come by They are $200-300 online. Not Toto quality, but plenty good enough.
macrolime 2y ago
The ERV itself is for removing CO2, not dust. Especially in cold climates where houses are built to be as air-tight as possible, these are a necessity. Even if you lived in a forest cabin you'd want filters to prevent too much dust and pollen. I've got a dual filter on mine, HEPA and activated carbon filter. The HEPA filter removes dust and pollen. I've found that if I don't use the carbon filter I get higher than recommended levels of NOx.
- open_erv2 2y ago
  You can add a filter to the TW4, there is an adapter/kit. It's a hepa filter from a car cabin filter system design. You rarely need both anti pollen and also ERV, so you would take the heat exchanger out and just use the filter and fan. As for dust, I recommend a good pc fan filter based appliance, not putting the filter in the flow path of the ERV.
jeroenhd 2y ago
Most people here just open a window when they want to air out a room. That said, that does waste a lot of energy when heating/cooling your home on cold/hot days, so ERVs and HRVs are used to get the clean air in without exchanging heat with the outside world too much. They're quite cheap and effective compared to just running normal ventilation.

block_dagger 2y ago

I live near a ten lane highway. I prefer to keep the outdoor air out, and the indoor air filtered. I could see this being very useful for other dwellings though.

amluto 2y ago
You are either already failing to keep outdoor air out or you are getting too little ventilation. What you want is something like this device with the H13 filter option. Maybe that plus carbon.
positr0n 2y ago
Think of it this way, since you aren't dying of asphyxiation when you sleep at night, you're already getting some air exchange with the outside air. With an ERV you can control how much air you get, and put whatever filter you want in between the outside air and your room. In fact the fancier systems will let you overpressure your house by running the fan pushing in slightly higher than the air pushing out, ensure air only leaks out of your house not in.