If I ever build my own house, the plan (if code allows) is to not have a bathroom fan, and instead run the intake for an air exchanger into the bathroom. If I remodel this one I may well try to do the same. I think there's a reasonably good spot for it.
Bathrooms, particularly public ones, are wet, mouldering places with insufficient ventilation. And we go into them every day to get ourselves clean. Taking air out of the bathroom and injecting it somewhere else is about the best way I can think of to fix that, and we only run them intermittently.
No hate, and good on you for thinking about it deeply, but this is a terrible idea. The primary thing you want to exhaust from bathrooms is humidity. You want the shortest, straightest path out of the house for that 100% humid air. Recirculating it will create untold horrors of mold all the way downstream of the bathroom. It’s also unlikely to be allowed by residential building codes, or passed by any inspector.
They said "If I ever build my own house" - I think the idea is to prevent it from becoming "shit air" in the first place by having the air exchange there from the beginning.
I think they meant “shit air” literally. As in, it doesn’t just smell like farts, it is actual farts, being proposed to be blown throughout the rest of the house
Does nobody hear know what an air/heat exchanger does? They’re for ventilating modern sealed construction so you don’t choke to death on fumes from your belongings, or get cancer from your wood shop.
I think the implication is he wants to run industrial air-changers 24/7, basically turning his bathroom into a fume-hood, and then venting it outside.
So, same idea as bathroom fan but really big and running it less intermittently. He wants a big industrial air-changer so his bathroom is less dank.
One problem is this will definitely suck a lot of heat out of the house. You might want to only run it when a sensor detects humidity, and just give it a ton of hysterisis/etc so that it runs a relatively long time. Pulling a bunch of heat out of your house 24/7 will be expensive and will cause other problems (like extreme low humidity since the furnace is running much more, which will lead to crazy amounts of static etc). You can of course run a humidifier (or whole-house humidifier) etc but it's generally not without problems to just dump air 24/7.
(I had similar sentiments around my current house not having good air handling for the stove, if you are frying something it can get pretty greasy/nasty inside even with the fan on, and you can't always open a window depending on the weather.)
On the other hand, this also might help with CO2/oxygen levels, which might lead to better overall health/comfort too, because your air is being cycled more aggressively. The overall thrust that houses are getting too airtight nowadays is generally correct, and this has negative health effects too. It is, again, unfortunately balanced against heating costs (energy efficiency seals the house up, then we circulate the air out...) and other problems. If the house is super breezy (or has air changers aggressively changing the air) then you're also pumping out all your heat and humidity.
If you are going to have some strong air changers though, you could run a heat pump in the air changer stage too. Being able to spend 1 unit of energy to move 10 units of heat from the exhaust back to the intake would be ideal, and the air is going outside anyway so you might as well dump waste cold (or waste heat, in the summer) outside while you're doing it.
An easier step, if you have the space in your bathroom, would just be to run a dehumidifier in the bathroom. Obviously would be pointless/inefficient during a shower, but maybe you could have a switch where one pole is "bathroom fan on" and the other one is "dehumidifier on". Or get a timer switch and just run it for an hour after the shower is done.
It is also worth noting that if you get the humidity under control in general, that the house itself will act as an "anchor" and tend to resist changes from the mean. The bathroom is dank because all the building materials around it are saturated and constantly giving off water, if you can keep it at 40-50% humidity more regularly then eventually they will dry out and the system stabilizes at a less-dank humidity.
My house in Minnesota had one. The building codes were such that the first winter without we had constant condensation on the windows, which ruined the finish. Installed one later that did 4 whole house air exchanges per hour. Best investment ever.
I first encountered consumer grade versions of these on This Old House. I’m not sure when, but I stopped watching it regularly probably twenty years ago, so at least fifteen?
At the time dust collection systems were still pretty exotic, so they were putting them into wood shops to make sure the dust didn’t get sucked into the rest of the house.
> If you're a homeowner, be sure that your fan is properly vented directly to the home's exterior via an insulated duct. "It was common in the '70s and '80s for it to be vented into the attic space," says Bayne. "Building codes today require that the exhaust is vented outside through insulated ducting to a roof vent that goes directly to the exterior." Otherwise, you may be contributing to moisture and mold problems in your attic or wall spaces.
Related, but I like how kitchen exhausts sometimes come out of a vent on the side of the house, so if you go out into the backyard you can walk by and smell bacon frying or whatever. (OTOH I once lived in a condo with an under-the-microwave exhaust that didn't actually vent outside, it just spat everything up onto the kitchen ceiling... a wet greasy spot accumulated up there before I realized what was going on.)
> (OTOH I once lived in a condo with an under-the-microwave exhaust that didn't actually vent outside, it just spat everything up onto the kitchen ceiling... a wet greasy spot accumulated up there before I realized what was going on.)
Isn't the primary purpose of a kitchen vent to remove smoke from the kitchen?
How on earth is moving smoke from one part of the kitchen to another part of the kitchen supposed to improve anything? Is your smoke alarm that location-sensitive? (What if there was a fire 20 feet away from the smoke alarm?) Will it be any easier to breathe?
AFAIK the only real purpose of the recirculating range hoods is to catch grease. And it sounds like GP's was missing the grease filter. (BTW, those get -really- gross pretty fast, it's worth cleaning them regularly)
You can get grease filters now with charcoal filters embedded within, and that might help a little bit with smoke.
Hey, at least they gave you that kindness. At the last place I lived, it was configured to spray everything all over the inside of the cabinet above the microwave.
Many years ago while helping fix up a friend's newly-bought house, I encountered the same thing, although fortunately it looked like it had never been used. My first thought was that it was somehow left unfinished for some reason, but apparently it's allowed, and even somewhat common.
Yeah, “properly” was doing some work in my response :) It helps to use a glossy paint, and to put that over wet-environment primer on top of wet-environment drywall.
Bathrooms, particularly public ones, are wet, mouldering places with insufficient ventilation. And we go into them every day to get ourselves clean. Taking air out of the bathroom and injecting it somewhere else is about the best way I can think of to fix that, and we only run them intermittently.