Van-dwelling in Wildfire season - fan/vents and air filters

[Samara]

Hey folks!
Despite owning a 2005 Sprinter for over three years and living in it for much of the last two, I've somehow only now just discovered this forum...
I'm curious, how are all of you other van-dwellers on the west coast are dealing with wildfire season?
The smoke's starting to get pretty bad up here in Washington, and is supposed to get way worse these next few days.

I was reading up about DIY HEPA filters/fan combinations, in which you can put a HEPA filter on the intake side of a box fan to filter the air circulating around, and was trying to figure out if I could rig something up like that in my van... only problem is that the fan/vent I have on my sprinter is the Maxxair 04301K, which is only a one way-exhaust fan...so it would be pointless to put a HEPA filter on the intake side of it because then it would be blowing filtered air outside the van instead of in, ya know?

I'm curious if anyone has found any solution to this or any other tips you might have about van-dwelling amidst this apocalyptic smoke.
Many thanks!
Samara

 

[Zundfolge]

Doubtful you could even buy one right now, and unbeknownst to me whether you'd have the power to run if if you could lay your paws on one, but I'd suggest tracking down a HEPA air purifier and just running it with all of the windows closed. If you don't have an inverter or enough battery storage then of course that's not an option.

Makes me wonder if you could wire your fan in reverse to switch the direction? Then do the diy filter thing? Those with more DC electrical experience could tell you if that would work or not.

If not that then you could potentially rig up a HEPA filter with tape/cardboard/plastic etc in one of your windows, and use your exhaust fan. That way you'd be pulling in mostly filtered air at least.

 

[RVBarry]

Hi,
Box fan, filter, twine or tape.
Watch your battery level.

The 4" thick filters not only filter better, but flow better too.
Higher MERV ratings catch more particles.

Air quality may be somewhat better at the coast.

 

[MsNomer]

And be sure to wash your solar panels. Ours accumulated a layer of soot in Colorado a couple weeks ago. Solar no workey under layer of soot.

 

[Samara]

Doubtful you could even buy one right now, and unbeknownst to me whether you'd have the power to run if if you could lay your paws on one, but I'd suggest tracking down a HEPA air purifier and just running it with all of the windows closed. If you don't have an inverter or enough battery storage then of course that's not an option.

Makes me wonder if you could wire your fan in reverse to switch the direction? Then do the diy filter thing? Those with more DC electrical experience could tell you if that would work or not.

If not that then you could potentially rig up a HEPA filter with tape/cardboard/plastic etc in one of your windows, and use your exhaust fan. That way you'd be pulling in mostly filtered air at least.

Thanks for the advice! I don't think I have enough battery juice to run a purifier unless of course there's a super low amp hour draw one out there...
That is a good idea about wiring the fan in reverse...I don't know if that's possible but I will investigate!

 

[Samara]

And be sure to wash your solar panels. Ours accumulated a layer of soot in Colorado a couple weeks ago. Solar no workey under layer of soot.

Thanks for mentioning that, I hadn't thought of that but now it seems obvious!

 

[Samara]

Hi,
Box fan, filter, twine or tape.
Watch your battery level.

The 4" thick filters not only filter better, but flow better too.
Higher MERV ratings catch more particles.

Air quality may be somewhat better at the coast.

yes I've seen this and it's a great idea! just gotta figure out if my battery can handle it or not...

 

[Zundfolge]

Anything's gonna require some juice if it's on full time. How many ah capacity you have? The least amount of work is to put a filter in your window and run your exhaust fan. But it's also the quickest way to dirty a filter since you're just pulling in lots of contaminated air. Recycling the indoor air is the best bet for filter life.

 

[Kajtek1]

I wonder what is you original cabin air filter?
On my NVC3, I have huge filter, who is carbon-plated, so not only it gives good filtration, but eliminate poisonous gases.
All it takes is to add bypass wires from blower to house battery and flip the switch.
Out of curiosity I check air filter prices and have whole bunch of stuff to choose from... including those who remove 100% of allergens

2015 Mercedes Sprinter 2500 RWD Auto Parts | AutohausAZ

www.autohausaz.com

 

[sprint2freedom]

I'm sitting in a van during bad wildfire smoke right now, and I would first advise keeping all your doors windows and vents closed as much as possible. It's not just particulates but VOCs and gases as well. There's no straightforward way to make outdoor air breathable when things are this bad, so instead I'd recommend filtering your indoor air to remove any particulates that manage to creep in when you're entering or exiting, or from numerous small points of entry (vans aren't airtight).

This thing looks promising for a van:
Levoit Core 300

Max power consumption is 45 watts, or about the same as a DC compressor fridge if they both ran constantly.
Rated for around 200 sqft.
Three fan speeds
8.7 x 8.7 x 14.2 inches
Cost $100

I would think that for wildfire smoke if your van is pretty airtight and buttoned up you could get the air inside cleaned to your satisfaction using a higher speed during the day and then switch it to a quieter, lower power mode at night.

Found this site with more power measurements:

Mode	Power (Watts)
Off	0-0.8
Sleep	10.4
Low	26.7
Med.	30.3
High	43.3

I don't know if the speeds of your 4301K will be an exact match, but here's a table of power consumption in a test of a MaxxFan:



Multiplying the current at each fan speed by by 12V to get power consumption in watts:
2.4
4.8
6.0
9.6
13.2
18.0
24.0
31.2
39.6
52.8

So as a rough guesstimate this thing appears to use about the same amount of power at your MaxxFan. The Levoit will use a bit more (10-15%) than the wattage in the first table because of inverter losses.

 

[sprintah]

While it remains this bad in multiple states, it might be a good idea to just wear an N95 mask even while inside the van. I see that Harbor Freight is now offering them.

 

[Kajtek1]

I'm sitting in a van during bad wildfire smoke right now, and I would first advise keeping all your doors windows and vents closed as much as possible. It's not just particulates but VOCs and gases as well. There's no straightforward way to make outdoor air breathable when things are this bad, so instead I'd recommend filtering your indoor air to remove any particulates that manage to creep in when you're entering or exiting, or from numerous small points of entry (vans aren't airtight).

Beware that Sprinters are pretty sealed vans. Beside front, filtered intake, they only have tiny outlets behind rear bumper, so with door seals in good condition - you don't have much air exchange.
That would bring me back to idea of using can cabin filter.
On MB sedans, the system who have bypass carbon filters you will also find air quality sensor. When sensor detects poisonous gases - it will switch to carbon filters and recycling mode.
But recycling mode will work only for about 1/2 hr and system will switch to fresh air to protect passengers.
One more feature where MB engineers are protecting stupid drivers.
When I bought Sprinter in bus version, I was really surprised how huge cabin filter is. But then I noticed that blower takes 100% fresh air and that explains the situation.
Bottom line - I don't think you can beat using factory cabin filter.
Fire season is not going to end soon, so stacking up few filters might be good idea.

 

[autostaretx]

That is a good idea about wiring the fan in reverse...I don't know if that's possible but I will investigate!

If you crawl up on the roof and open/remove the cover, you'll see the two motor wires snaking out in the groove of one of the supporting "spiders". That's where you'd intervene with a reversing switch.
On my MaxxFan, that spider had a tie-wrap at each end (shown in photo):



It would want to be a "double pole double throw" switch, wired like the "center" switch in a 3-way lighting circuit.



Remember that you can only do this to the motor leads themselves ... you CAN NOT reverse the current flow to the entire fan unit (the electronics would fry)

--dick (who really does intend to getting around to that modification to his own fan ... someday)

 

[sprint2freedom]

With the terrible air quality from ground-level wildfire smoke currently affecting my current location as well as numerous western states, I talked myself into buying one of these off eBay. It's not the model I suggested in my earlier post, but it's fairly similar and was in stock (at the time).

Fire season doesn't show any signs of being over soon, and while traveling we are bound to end up in or at least pass through other smoke-affected areas. Since this could very well be the "new normal" I decided to take the hit of using some storage space for an air purifier. It could even be run from the inverter to clean air inside the cab if it could somehow be kept on recirculate.

The manufacturer rates it for 129 sqft and a max power consumption of 28 watts at the highest fan speed. That's similar to running the MaxxFan at speed 7 out of 10.

I should have it in hand a few days from now. I'll report back once I have a chance to test it out!

 

[sprint2freedom]

OK, here's the update I promised:

Having a HEPA filter in the van rocks! This was a somewhat unexpected result as I've never owned or used such an appliance before. But, similar to employing a furnace in a cold place giving you a warm refuge in which to relax, having such a filter allows you to create and maintain a bubble of clean air in an otherwise smoky or dusty place.

We were recently trapped in an RV park while making an emergency serpentine belt repair, and all the homes in the area were heating with wood- a cheap and widely available fuel, no doubt. But I swear they were also adding big heaps of wet fallen leaves because their chimneys were putting out foul, stinking smoke that oozed out of the stacks unenergetically then sank to the ground and diffused into a sickly haze.

Since we couldn't realistically relocate the van somewhere with clean air, going outside at all when the wind wasn't blowing just right was a choking affair that stunk up clothes, hair and skin. The little HEPA filter ran 24/7 and within about 15-20 minutes of coming back inside it succeeded in clearing the air of any smoke smell whatsoever. Of course it was still necessary to change clothes and wipe down with a washcloth, but it was a huge quality of life improvement.

This particular unit has three speeds. Speed 1 is barely audible, speed 2 is quiet (audible but not disruptive), and speed 3 puts out a steady wooshing sound which has the secondary purpose of creating white noise to drown out highway or other noise. Obviously, speed 3 works best for clearing smoke from the air.

 

[unicornTDI]

Any small HEPA filter that has a block adapter? Typically appliances with block adapters have an input of 100-240v AC and an output of 12v or 24v DC. So by removing the adapter you can end up with a 12v appliance, no need to run the inverter.