How does air come into HEPA air intake

[stealthtes]

If you look at the diagram of the HEPA air intake, the opening is actually behind of the frunk, underneath the hood. This doesn’t seem like a very convenient spot to allow to flow in. I’d only imagine that the air has to come from underneath the car? Do anyone have any idea where else the air can come from?

To me, when I have recirculating air off, the Tesla seems to let in less air than the my previous car’s. Can this be why?

 

[Tam]

...I’d only imagine that the air has to come from underneath the car?

Getting air from underneath is not a good idea because of the road's contaminants and debris. Your naked eyes can't visualize the microscopic debris flying up from the road surface but they are there!

It's logical to get it at a sheltered location as it's designed currently.

To me, when I have recirculating air off, the Tesla seems to let in less air than the my previous car’s. Can this be why?

When the recirculation is off, the maximum air flow is still very uncomfortably loud and very strong in Tesla.

Maybe you mean not as "cool" which is a different subject.

 

[stealthtes]

But how does air get into the sheltered location? It would have to either seep into the panel gaps of the hood on top or come in through the bottom of the car, through all the parts.

On recirculated air off, I just meant driving without turning on the fan. Usually in other cars, air will come in naturally as you drive faster. But in the Tesla Model Y 2023, it gets stuffy really fast unless you turn on the fan.

 

[E90alex]

It pulls air in between the hood and plastic frunk trim right below the windshield wipers. That area is open and not sealed off when the hood is closed.

 

[pinolero]

Does the fan speed eventually lower or does it stay loud when BDM stays enabled? I've tried it for a bit but got tired of the loud fan noise.

 

[BitJam]

Does the fan speed eventually lower or does it stay loud when BDM stays enabled? I've tried it for a bit but got tired of the loud fan noise.

I think it always stays loud but you probably don't need BDM most of the time. BDM is designed to pressurize the cabin so no air comes into it except through the HEPA filter. It needs the fan on full to keep the cabin pressurized.

Normally plenty of fresh air comes in through the door "seals". This is one of the reasons why camp mode with recirculation is safe. There is almost no risk of running out of oxygen.

 

[E90alex]

Does the fan speed eventually lower or does it stay loud when BDM stays enabled? I've tried it for a bit but got tired of the loud fan noise.

As mentioned, Bioweapon Defense Mode is meant to maintain positive cabin pressure to help prevent outside air (with bio weapons) from leaking into the cabin from anywhere except the HVAC system where the air will be filtered.

It’s more or less just a gimmick/party trick as you likely will never need to use it in real life. It’s not meant to be used normally. Just having the HVAC on normally will provide you with filtered air just fine.

 

[Farmer]

I've only had my Y for 3 weeks, so I haven't tested BDM, but ignoring the stupid name, I thought that it might be useful for temporary use in keeping bad odors out of the car, such as when driving by a pavement plant a few miles from me or when I see a skunk get run over in front of me (yes, that happened once) or maybe when the gas clunker up in front of me starts pumping out blue smoke.

 

[unhyphy]

As mentioned, Bioweapon Defense Mode is meant to maintain positive cabin pressure to help prevent outside air (with bio weapons) from leaking into the cabin from anywhere except the HVAC system where the air will be filtered.

It’s more or less just a gimmick/party trick as you likely will never need to use it in real life. It’s not meant to be used normally. Just having the HVAC on normally will provide you with filtered air just fine.

More likely to be used to avoid breathing wildfire smoke, IMHO.

 

[BitJam]

More likely to be used to avoid breathing wildfire smoke, IMHO.

Agreed! I'm still hoping I will be able to get a retrofit. BWD mode plus 24 hours of A/C make the car a good backup for several otherwise dire situations.

 

[pinolero]

I've only had my Y for 3 weeks, so I haven't tested BDM, but ignoring the stupid name, I thought that it might be useful for temporary use in keeping bad odors out of the car, such as when driving by a pavement plant a few miles from me or when I see a skunk get run over in front of me (yes, that happened once) or maybe when the gas clunker up in front of me starts pumping out blue smoke.

Yeah was thinking the same thing, but will probably use it for Springtime weather as I have a kid who sneezes a bit during that time. Discovered that if you put mulch in the frunk and circulate, you get a whiff of mulch air, finally discovered that the circulate icon doe does not mean closed as in previous vehicles I've owned. At least I had a cold Sangria waiting for me when I got home after a long day of work.

 

[stealthtes]

Yeah was thinking the same thing, but will probably use it for Springtime weather as I have a kid who sneezes a bit during that time. Discovered that if you put mulch in the frunk and circulate, you get a whiff of mulch air, finally discovered that the circulate icon doe does not mean closed as in previous vehicles I've owned. At least I had a cold Sangria waiting for me when I got home after a long day of work.

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Wait. You’re saying that when the recirculating air button is blue / on, it’s not actually recirculating air?

 

[pinolero]

Wait. You’re saying that when the recirculating air button is blue / on, it’s not actually recirculati

I'm new here, I just went with what I smelled. When it was lit, I smelled hints of mulch, when it was not, I did not smell it. Maybe a veteran can chime in and educate me to ensure I'm understanding things correctly.

 

[Farmer]

Airflow may leak a bit around the closed outside air baffle at times, but I'm pretty sure the recirc. button operates such a damper baffle that opens and closes to outside air. When poking around Service Mode sometime 2 weeks ago, in the HVAC section, I saw an animated pictorial view of the interior HVAC hardware and it had the damper/baffle on it that opened and closed to the outside air duct when the recirculating button was cycled. It made sense at the time.

 

[Resist]

The damper that closes in Recirc mode isn't SpaceX airtight, so some smells might still leak into the cabin.