Fresh Air, Ventilation, and Heat Booster Fan Install

[AlmostHeavenWV_VW]

Okay guys, so here it is- my Defrost/ventilation/heat booster fan set up. I thought quite a long time about this and tried to plan it well. Researched here on TheSamba, looked at stuff on the interwebs, googled many many times with different terms, looked at lots of types and set ups of 'blower fans' or 'bilge fans' or 'in-line fans' etc etc etc etc.....

Of course, all plans must abide by my motto whenever I work on things:

"Modification Without Alteration"

Meaning that while I aim to improve things, I also attempt to leave things/design things so that the stock/original set up is intact, or able to be restored with little effort or time. You'll, hopefully, see what I mean and also appreciate the months of planning for this system.

So what were all the criteria for this project?
1) Had to abide by my motto, as stated above
2) Had to actually produce a noticeable effect
3) Be able to assist in both defrost and ventilation for the driver/passenger
4) Be able to be used with both the fresh air (cooling) and heat functionality of the stock set up- without complicated designs and unnecessary components (Keep It Simple)
5) Be readily reversible should I- or anyone else- decide to remove the system and revert back to the stock set ups
6) Not use rare/hard to find parts
7) Be generally cost-effective

Bonus point criteria:
1) Be adaptable to both standards, flat screen supers, and curved screen supers
2) Potential adaptability to other ACVW models
3) Be easy to replicate so that all my fellow ACVW brothers and sisters could install similar, if they desire

Long story short, I managed to plan and achieve all of these goals.
-----I'll take a moment here to thank Vamram for his help and PM'ing back and forth with me to help me plan for the adaptations for the Supers- SAVE THE SUPERS, RIGHT VAMRAM?!?!?

Seriously though,>>> Thanks Vamram<<<- couldn't have been able to help out you Super Beetle folks without Vamram's experience/insight into the supers' systems

There are some additional adaptations/parts for you curved-screen supers, and I'll point those out as we go and talk about how to perform the adaptations towards the end.
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[AlmostHeavenWV_VW]

General Principle:
Okay, so this system will boost the air flow for heat/fresh-air through the vent which is in front of the driver or passenger (the one with the little lever if you have standard or flat screen super)


( curved screen folks: This will be boosting through your side vents in the dash and the defrost vent which is in front of the driver or passenger up next to the window- your fresh air system is separate so you'll end up with two sets of fans - 1) the OEM fresh air fan for the central dash vents & 2) These two new independent fans for the side vents/defrosters)
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[AlmostHeavenWV_VW]

Tools I used:
---Wire strippers
---Wire Connector "crimper" pliers
---Needlenose pliers
---Scissors
--- Razor blade/ Safety knife/ "box cutter"/ utility knife (whatever you want to call it)
---Lighter (like the ones for lighting the BBQ)

Parts List:
Standard, Flat-screen, Curved-screen

---Rolls of primary wire of your desired color scheme (I used red & black because that's what I'm used to and helps me to define my "user added" wiring apart from the OEM wiring)
--- Appropriate sized wire connectors
---Some wiring shrink wrap
--- Two switches (style of your choice- I bought 'rocker' switches)
--- A double switch panel (matching the style of switches you have)
--- In line fuse holders (if you don't have an accessory fuse block already installed)
--- Wire connector "piggybacks" or "splitters" (whichever type you think will work better for you)
https://www.jbugs.com/product/558958.html
https://www.jbugs.com/product/558928.html
https://www.jbugs.com/product/5531380.html
--- #8 x 1" sheet metal screws ( to replace the dash pad screw that you'll take out)
--- 1 pack #8 flat washers (to shim replacement screw to secure the switch panel)
---2 inline "helmet fans" (if you want to boost both sides) (available at multiple online dealers)
https://www.summitracing.com/parts/aaf-all13011
https://www.jegs.com/i/Allstar-Performance/049/ALL13011/10002/-1
---Defrost tubes (enough to replace yours if you need to replace yours- I did because mine were pretty old/tattered)
http://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=113819723A
https://www.jbugs.com/product/113819723A.html
---Roll of electrical tape
--- A pack of zip ties (10" should be plenty long enough)
--- A roll of rubberized kitchen drawer liner (or something like it)
https://www.lowes.com/pd/Duck-20-in-x-12-ft-Black-Shelf-Liner/999959993


Curved screen Supers only
---4 "fernco" rubber couplers ( I'd buy four of both sizes, because I'm not exactly sure which will fit the system best- can always return the un-used ones afterwards)
https://www.lowes.com/pd/Fernco-1-1-2-in-x-1-94-in-dia-Flexible-PVC-Coupling-Fittings/1000075329
https://www.lowes.com/pd/Fernco-1-1-4-in-x-1-63-in-dia-Flexible-PVC-Coupling-Fittings/1000075345
---A piece of the larger size defrost/heat hose
http://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=133819365
https://www.jbugs.com/product/133819365.html
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[AlmostHeavenWV_VW]

Gather all supplies & tools
Prepare workspace
Gather cold refreshments of your choice


Alright, let's get started:
How To:
1) *****DISCONNECT THE BATTERY SO YOU DON'T SHORT ANYTHING AND/OR "LET THE SMOKE OUT" AND/OR SHOCK YOURSELF AND/OR START A FIRE*****

2) Remove old defrost hoses and get out the new hoses (if necessary)

3) Measure/mock up where you want the fan to be 'spliced' into the hose (I chose about midway so that the fan could be held by the OEM bracket thingy for the tubes on each side)

4) Cut hose at desired point

5) Fit bottom hose piece to the "3-way splitter" which comes up "the void" in the front fender

6) Note end of the fan is "air in" and which is "air out" (you want the "out" side towards the dash- "in" side goes towards the "3-way splitter") [I made a sharpie arrow on the fan so I knew which way was the airflow direction- you can test this on the workbench by connecting the fan leads up to a 9volt household battery]

7) Insert fan into bottom defrost hose half, stick upper hose on fan and connect to OEM stub on defrost/fresh air vent duct

8 ) Wrap junction points in electrical tape to help seal/hold everything in place

9) Wrap fan body in rubber liner to reduce noise and prevent 'rattling' or 'vibration transmission'
10) Bend bracket thingy down to secure fan/defrost hoses

11) Run (+) wires to power source- I used a 'switched-on' source so that my accessory fans weren't "live" all the time

(use an line fuse and/or accessory fuse block- just make sure your wires are properly protected with fused links)

12) Run (-) wires from fans into cabin (I chose to run my wires through the old washer hose hole from the stock windshield washer system- I could do this because I had previously removed these hoses when I converted to a 12volt washer pump system) ( this hole is immediately to the right of the steering column) (also see here is my 'momentary on' push button switch for the 12v washer pump system)

****Repeat above steps (#2-12) for the other side*****


13) Now I selected a dash pad screw location which seemed to be accessible to both driver and passenger. I ended up using the screw which was located near the "4-way hazard/flashers" switch.

14) Remove the short, stock dash pad screw.

15) Retrieve the #8 x 1" screw and #8 washers

16) Take the screw and stack the washers onto the screw until the washer stack is flush with the bottom of the dash-pad when the washer stack is pushed up against the base of the dash pad screw hole. This provides a surface to 'squeeze' onto for mounting the switch panel. Getting the right amount of washers is just trial and error, add a few, remove a few until you get the right number (and thickness) of washers stacked onto the screw.

17) At this point, I then fed my (-) return wires up through the same hole though the metal dash which I used to bring the (-) leads from the fans. Pull sufficient lengths of wire up into the trunk to reach your chosen grounding points.

18 ) Apply to all wires (fan (+), fan (-) to switch, (-) from switch to grounds) your preferred, appropriately sized wire 'quick disconnects'/'spades'/'crimp terminals'- whatever you want to call them, these things:
https://www.amazon.com/Insulated-Connector-Electrical-Terminal-18-22AWG/dp/B00FZK932G
https://www.amazon.com/Insulated-Connector-Electrical-Terminal-14-16AWG/dp/B00FZK947A
https://www.alliedelec.com/te-connectivity-42238-2...XMQAvD_BwE

***Use shrink wrap to secure and insulate connector junctions

***I ran my interior wires through the switch panel slots and hooked up my switches before mounting the panel to the dash- it just gives you a little more room to work vs trying to connect everything with the switch panel already mounted to the dash.

19) Mount switches into panel

20) Fasten switch panel to dash using the screw and washers from earlier (washer stack will go on top of the switch panel between the panel and the base of the dash/screw hole in the dash)

Curved screen folks: I don't know if you have a similar dash screw hole or not- forgot to ask Vamram about this part- sorry. Mount the switches however you feel best



21) Go back into the trunk and connect the leads to the appropriate places you selected earlier in the planning stages.

22) Reconnect the battery and verify that nothing is smoking, no fuses popped and all electricals are in working order

23) Clean up

Before:

After (also can see the accessory fuse block I installed during this project)

Now, fire the car up and check out the handy work!

Hope this helps, and as always:

Happy Bug'n
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[AlmostHeavenWV_VW]

Curved screen folks only

Okay, so you've seen the system, but for you to use a similar set up a few modifications to the plan must be made because you guys don't have the "3way splitter" which then connects to the dash with the smaller 1 1/4" diameter hose.

Your 1 7/8" hose comes straight from the heater channel and connects directly to the dash, so to use the same fans that I did, you'll need those flexible rubber couplings I listed earlier.

To do this system in the curved-screen super, follow the instructions as above except:

--Disconnect the heater hose from the dash and slide the larger end of the coupling onto the hose. Tighten down the band clamp if possible.
--Take a piece of the smaller (1 1/4") hose and slide into the smaller end of the rubber coupling- tighten the band clamp.
--Place the fan into the other end of the small hose, stick another short piece of 1 1/4" hose onto the other end of the fan and reverse the set up of hoses and couplers.
--Stick the smaller end of the coupler onto the open end of the small hose, tighten the clamp, take a piece of the larger (1 7/8") hose you bought and slide into the larger end of the coupler, tighten the clamp and trim the larger hose to length to allow you to hook back into the original dash port.
Repeat this process on the other side.
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[AlmostHeavenWV_VW]

Some diagrams to show how the system works:

Optional "grafting" of the fan system. Basically you have a 'bypass' hose for the fan, instead of having it directly 'in line'

_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[AlmostHeavenWV_VW]

Update:

Took the Bug out early this morning to give this set up a proper trial at defrosting/ defogging the windshield.

Turn them on as soon as I got in. Hit the wipers once and drove off.

Kept the windows up, and ended up behind the transit bus today (stop and go driving out the road) Fans got the windshield defrosted/defogged completely much, much sooner than usual.

Estimated relative 'power' of these fans:

Fan on = 40mph fresh air box flow


I'm happy with the results
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[baldessariclan]

Gotta admit, this sure looks like an interesting mod idea -- good work!! Couple quick questions on your experience with it so far:

-- What's the noise level like coming through from those inline fans in the defrost tubes? I've seen similar setups used in house forced-air ducting, and the sound from those ducting fans can get to be a bit much in some cases. Maybe these are more "computer" style (i.e. "silent flow") fans that you've found and are using, though -- ??

-- Any worries about heated air in the system being hot enough to potentially cause any problems (melting / burning, or similar) with those added fans? I know it can get pretty hot down at the foot vents, but maybe the air is able to cool enough by time gets up to defrost tubing where won't be an issue -- ??

In any case, be interested to hear how it works out in long run -- please keep us posted!
_________________
1971 Standard Beetle — fairly stock / driver

baldessariclan -- often in error, never in doubt...

[AlmostHeavenWV_VW]

[vamram]

Nice write up. Thanks for the generous shout-out, but I hardly said anything other than "looks good to me!"

Btw, i'd be trying this out if I still had my '72 flat windshield Super. Fan flow is so good on my '74 Super that no after market solutions are need, imho.
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[sjbartnik]

Nice job.

To be really slick, get yourself a stock fan switch from a later Beetle and mount it on the dash to make it look factory.

The only concern one might have with adding a fan into the heat system after the heat exchangers is potentially creating a suction effect whereby exhaust gases could be drawn into the system if you have leaky exhaust components or heat exchangers.

Even when VW put in a fresh air fan on later models, it was independent of the heater and served to bring in fresh air only from the cowl vents below the windshield.

Just something for you and others to consider as they contemplate this kind of job. Don't gas yourself!
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[SdAufKla]

I wish the PO of my Bug had done something like this rather than put electric booster fans in the Y pipes / heater ducts under the rear seat.

He cut up both of those to insert the booster fans and now that I'm restoring my car, they're just one more thing that I've got replace. (Pretty easy to find, but still gotta find 'em and replace 'em…)

He did it because the heater channels were rusted through on both sides, so he wasn't getting any real heat into the passenger compartment. As it was, all that the fans were doing was blowing the warm air out through the rust holes - some inside the car but most outside.

[Brian]

Dang, I wanna try this out because why not.

Those helmet fans are pretty nifty. Funny that they look just like some fans I have laying around

12 Volt DC 40mm Counter Rotating Tubeaxial Fan PWM Control 31 CFM
_________________
Wash your hands

'69 Bug
'68 Baja Truck
'71 Bug
'68 Camper

Only losers litter

[vamram]

[AlmostHeavenWV_VW]

Just a little follow up on this:

#1
Been running the heat (whether I needed it or not) over the past couple days up through the dash with the fans on to see if the fans got 'tired' or overheated when the heat is on.
No issues so far. The fans appear to be able to handle the heater (at least until I start sweating and can't stand the heat in the cabin )

#2
Was a little cooler this AM (54*F) on the drive into work today.

Did a side-by-side comparison with the heated defrost:
Drivers: Inline fan on
Passenger: Inline fan off

With the heat on and fan on, windshield on the driver's side was defogged in about a 1/3 of the time as the passenger side.
( this was a little faster defogging action than the other day when I did it with just "plain fresh air"- not really surprised there.)

Test was with fairly consistent speed between 30-45mph in 3rd gear. No start/stop traffic today (got ahead of the school bus today)
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[AlmostHeavenWV_VW]

Update again:

Back a few months ago, I took the bug back to my hometown (about 1 1/2hrs away) to use Dad's garage and expertise to replace the front wheel bearings and replace the bakelite tubes under the rear seat. After replacing those bakelites, my stock heat really got good airflow and heated air on it's own.

On the drive back (1 1/2 hrs at 65mph) the heat really was toasty (I had to keep a vent window cracked while the heat was on in 40* outside temps). Ran with the heat on the whole way to try and 'stress' these booster fans I installed.

They seemed unbothered by the heat. I think they will survive just fine in the long term.

I actually used them just the other day when we had clear, dry roads and took an afternoon drive in the bug. Fans are still operating as new.
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[AlmostHeavenWV_VW]

Just wanted to drop by and give an update:

Booster fans have survived now for 10 months (including running the heater last fall/winter/spring extensively with the chilly temps).

One hiccup I had: my driver's side fan quit working, but I could hear it 'clicking' as though it wanted to work. Pulled it out and determined that a small piece of crumbly dash vent fell down and jammed the fan blade. I removed that little piece jamming it up and now it works great.


Still going strong!
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[VW_Jimbo]

Thanks for the update! I have been contemplating adding this upgrade to my Bug. It would be so nice! However, it is summer time again, so it is going to sit on the back burner, but I will keep this thread in mind.

Thanks man!
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[AlmostHeavenWV_VW]

Update:

Fans are still going strong. They do help draw in extra fresh air during the summer months while driving along.

No changes in performance that I can note.

[AlmostHeavenWV_VW]

Update:

Over 1 year in service and this set with the helmet fans is still fully functional. This has included several times with long highway runs with the OEM heat full on.

Summary:
The boost to air flow for defrost is invaluable on cool/frosty/damp mornings
The ability to increase the heat flow for passenger/driver dash vent is very nice
The helmet fans running are reasonably quiet when running
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor