wall vent question

[RetireJapan]

We have a pretty airtight home so usually leave a window cracked. My wife's parents' place (that we renovated a few years ago) has heat-exchange mechanical ventilation. Wonderful.

We weren't able to retrofit it to our manshon.

Wish it was in all buildings here (along with decent insulation).

[northSaver]

You've gotta close those vents. They for people who are too stupid to air out by hand on a regular basis. Also, you've gotta disable any of those 24/7 running fans. Absolutely stupid nonsense. At least in winter and summer.

Just air out your apartment 3-4 times per day. Once when waking up, once when going to bed and at least one time in between. All the air should be exchanged, so depending on your floor plan and number of windows, in winter that can take just 3 minutes or 15 minutes if you have only balcony doors.

Whenever you take a shower/bath or do cooking/boiling water or increase the air humidity a lot in other ways, you should of course air out as well. And when you take a shower, keep the door open and turn on the ventilation for an hour - and then after half a day, turn it on again for an hour.

That will save you tons of energy and make your apartment more comfortable.

Japanese government *should* actually mandate that all newly build apartments come with heat recovery systems instead of those stupidly dumb holes in the wall that they call vents - but yeah, one can dream...

In Hokkaido we crave heat and humidity in winter. It would be ludicrous to open windows just before you go to bed if it's -10 C outside. And silly to let the lovely warm moist air left after a shower escape outside!

This link answers my question somewhat:

"Where Does The Air The Fan Is Exhausting Out Come From? The fan is pulling air from air leaks, cracks in your home, and/or a combustion air inlet (a flexible ductwork tube that goes into your mechanical room)."

Also:

"We recommend running the fan continuously, 24/7. By running it all the time, the fan can be set at a lower, less noisy speed. Fans typically cost around $7-$15 per year in electricity costs to operate continuously. Other associated costs include exhausting already heated or cooled air from the home."

And:

"The savings from air sealing and insulation work are typically much greater than the small amount of air the fan removes from the home."

This puts my mind at ease a bit. And makes me think the house builders and habitants aren't quite as thick as you think they are.

[captainspoke]

Long ago I lived in korea, where the floors (at that time) were warmed with the heat (gases/fumes) of coal burning just outside the room, ducted under the floor and out the other side to a chimney.

So while the floors were toasty warm, you always kept a window open so that any leakage thru the floor--carbon monoxide--wouldn't kill you.

[AreTheyTheLemmings?]

Long ago I lived in korea, where the floors (at that time) were warmed with the heat (gases/fumes) of coal burning just outside the room, ducted under the floor and out the other side to a chimney.

So while the floors were toasty warm, you always kept a window open so that any leakage thru the floor--carbon monoxide--wouldn't kill you.

FAN DEATH!

[douglasxwilliams]

Hey all....

Thanks for the additional info and anecdotes!

As for me, i ended up (for now) just taping some plastic on the outside vent. The home center near my place normally has some covers, but they were sold out. Maybe other folks were having the same issue?

And, I noticed two effects after taping the plastic over the vent:
1. The living/dining area is a lot warmer in the morning. Normally, when we come into this area first thing in the morning, it is cold, cold, cold.
2. As some have mentioned, the front door requires extra strength to open. It feels like i am trying to force open a hatch on a submarine or spaceship! But, not a big deal.

We do open the balcony door at time and also the windows in the other rooms to bring in some fresh/cold air. Also, our place does have a 24/7 ventilation system.

I like the idea of that heat-exchange/recovery system. I might have to check into it for the future.

Again, thanks to everyone for the help!

[Roger Van Zant]

Hi all....

We moved into a mansion and there are two vents in our living room. i found a similar image online and attached here.

My question is...is there any way for me to reduce the amount of freezing cold air coming in? I can push on the vent cover and it "closes", but still more air seeps in from the vent that way. Maybe that is a problem? I was thinking of covering it up on the outside, at least overnight during the winter, but wasn't sure if that is a good idea. Before this mansion, i lived in apartments in Kyoto and in Tokyo, and they had similar vents, but i could actually push them close and very little, if any, air would come in.

thanks for any suggestions or help!

I have the air vents you posted a photo of. When you push them in to the "close" position, the air comes out even more forcefully and noisily due to the Venturi effect. It's the most stupid thing ever.

[Deep Blue]

Also:

"We recommend running the fan continuously, 24/7. By running it all the time, the fan can be set at a lower, less noisy speed. Fans typically cost around $7-$15 per year in electricity costs to operate continuously. Other associated costs include exhausting already heated or cooled air from the home."

I thought this sounded wrong but I just ran the numbers and it’s ballpark correct - assuming a fan uses 20 Watts then running it 24x7 for a year at 27 yen/kWh is about 4700 yen, so around 30 bucks.

Surprised it’s that cheap, I didn’t realize they used such a small amount of power.

[ChapInTokyo]

Hi all....

We moved into a mansion and there are two vents in our living room. i found a similar image online and attached here.

My question is...is there any way for me to reduce the amount of freezing cold air coming in? I can push on the vent cover and it "closes", but still more air seeps in from the vent that way. Maybe that is a problem? I was thinking of covering it up on the outside, at least overnight during the winter, but wasn't sure if that is a good idea. Before this mansion, i lived in apartments in Kyoto and in Tokyo, and they had similar vents, but i could actually push them close and very little, if any, air would come in.

thanks for any suggestions or help!

I have the air vents you posted a photo of. When you push them in to the "close" position, the air comes out even more forcefully and noisily due to the Venturi effect. It's the most stupid thing ever.

It closes to keep the rain out during typhoons. RTFM...



Nasta屋内換気口取扱説明書（お客様用）
https://www.nasta.co.jp/product/upload_ ... 008-03.pdf

[AreTheyTheLemmings?]

I would gladly pay 2,000 yen to see a show a band called

the Venturi effect

[adamu]

Maybe invest in PM 2.5, CO2, temperature and humidity sensors, then experiment with turning off the 24hr fan and closing the vent.

I live in a 20yo place with none of that fancy stuff. So if I put the bathroom fan on, the air starts rushing *in* through the kitchen hood unless I also open a window. I don't really like the idea of greasy air being sucked into the place, so either have to be cold after taking a shower, or let the bathroom incubate until I go out...