HV Battery Fan Air Filter Mod

Well I did attempt.
I got a 36x18 air filter(9merv), cut 5" wide and 36" long strip.
That turned out to be to long and restrictive once squeezed in the hole.
I cut about 2/3 off(about 12" long now) and now the filter breaths(well i can breath trough it like it was with the original filter, but with more peeks and valleys for more surface area). Does not seem restrictive to me.

Here are some pics:

 

The more surface area the less restrictive a filter is. As long as the peeks and Valleys of the filter are not touching you are getting more flow.

I do wish I could run a test of the HV battery fan on a certain speed and use a CFM-Monitoring Device to see the difference. If I knew how to make the fan run I would buy a CFM-Monitor.

Since ive had it, ive never felt the fan running with my hand while driving. (Even before the filter mod.)

I do new home inspections and it is DUSTY at all the new neighborhoods. To me, this will hopfully keep it clean as I like to have my windows down on good weather days.

 

There is not a filter of any type on the HV Battery Fan Blower(other than a mesh screen{like a window screen} that lets dust through).

 

OK, I did some testing.
I got an old PC 12v fan and hooked it up to a Volt Meter.
Using Torque, I set the HV Battery Fan to 6(Max)

With the outer covering off:
With the air flowing through the pc fan, no filter, directly on the HV Battery Fan, I got a reading of 4.43 Volts being made from my PC 12v fan.
Adding the Air Filter I got 0.300 Volts (300mv) being made from my PC 12v fan.(also tried increasing and decreasing the surface area of the filter with same results) 93.2% Reduction

With the outer Covering on:
No Filter - 3.5 Volts being made from my PC 12v fan.
With Filter - Could not get the PC fan to turn. Unknown% Reduction

Conclusion:
Not going to keep the air filter on.
If Toyota decided not to have an air filter on the HV Battery Fan then maybe there should not be one.
Even though I will be in a dusty environment most of the time being in New Home Construction.
I guess just keep the windows rolled up, use the A/C system and its filter to filter the air.


Just wondering, were does the HV Battery fan Exhaust to?
Any comments? Please let me know.

 

Did another test with different filters.
This time I used Foam Filters with better and more promising results. They came from PC add-on air filters for your PC fans.
Also, a picture to contrast the size of the holes(Coarseness) between the filters and the OEM Mesh Screen.




Still using my PC fan as the % reduction.

With the outer covering off:3-9-15
With the air flowing through the pc fan, no filter, directly on the HV Battery Fan, I got a reading of 4.20 Volts being made from my PC 12v fan.
With the Less Coarse filter the Voltage dropped to 3.60 Volts. 14.2% Reduction.
With the More Coarse filter the Voltage dropped to 3.46 Volts. 17.6% Reduction
With both, Less Coarse in front then More Coarse in back, Voltage Drop to 3.20 Volts. 23.8% Reduction
End, rechecked without filters and got 4.20 Volts.

I think I will use the More Coarse Foam Filter to help keep the dust out and clean it every 5,000 miles(but will check every 1,000 for the first 2k to see how it is doing).

These results are more promising than the Fiber Filter I first Tested.

Comments & Questions are welcome.

 

I got these filters from Microcenter, (A local computer mega store). Im sure you can get them from any online store like NewEgg.com

Coarse Filter:
Kingwin 120mm Fan Filter: microcenter.com/product/410252/120mm_Fan_Filter
Less Coarse Filter:
Evercool 120mm Plastic Finger Guard with Filter(FGP-120): ::EVERCOOL Thermal Co., Ltd. ::

I wish I knew were to just get the foam from, but you can't beet 4.99 each for a reusable filter pre cut basically. Also, just wash it out and reuse for the life of the vehicle.(Meaning I could just put it over the fan and put the plastic on to hold it in place, or just trim it a little to fit inside the plastic hole.)

From looking at this site below, it seems I have a 30 holes per inch and maybe a 100 holes per inch foam filters.
Plastic Fan Filter Assemblies

Here is the More Coarse Foam Filter Installed. It kindove stuck to the foam cushion around the fan. Then I put the plastic on that goes under the seat, and it holds it in place.


Regards.