Fresh air ventilation with Vintage Air

[jannes_z-28]

The way Vintage Air ( I guess it's the same for others too) installs, you block off the fresh air inlets preventing proper ventilation inside the car. This is not a problem in hot climates like the southern parts of USA. But if you live in a part of the world like I do you have to turn on the heat on cold summer nights and then you're in big trouble. When doing that the front window instantly mist up and you can't see out! The blocking of the fresh air also gives a stale feel inside the car.

I have been thinking a lot on how to solve this and have now come up with this solution.

I used the inlet on the passenger side, cut it of at the base and turned it upside down and attached it back. This give the hose attachment a different angle so I can run the hose away from the one coming from the AC-unit to the dash vent. The flexhose is then routed down to the AC inletbox giving fresh air right in to the AC-unit. The inlet has a flapdoor that can be closed, it is normally controlled to one of the handles in the kickpanel. I used a wire that I control from my instrument panel, it's one of those kind of old style choke wires.

Haven't been out and tried this yet but I am convinced this will prevent any fogging up on my windscreen in the future. It will also keep the AC-unit dryer than it has been before, some of the condensing water usually stays at the bottom and it will now be wented away.

Here is some pictures of what I did. Hope it will inspire you.


Air inlet modified


Inlet mounted in body, notice the vent inlet to the right that normally lines up with the other part.


Hose from the inlet.


Hose going down into the AC-unit.




Jan

[67ls]

did you cut a hole on the top of your blower box to get the fresh air in.

[jannes_z-28]

No the one I have is open on the top

[67ls]

what year make and model is this unit in.

[jannes_z-28]

In a 69 Camaro

[MIKE67]

Please follow up with a report when you have run it awhile. I have the same concerns in a 67. I am debating reworking the OE AC or using an aftermarket unit.

Thanks

[Vegas69]

That's a good idea Jan. I kept my lower astro ventilation but blocked off the cowl with my vintage air. I'm in the desert so I've never seen a fogged window.

[Romulus]

I'm glad I'm not the only one OCD enough to over think this stuff.

I'm lucky (so to speak) as I'm doing a '60 Vette and just keeping the giant "Mr. Mouth" fresh air vent in the center of the windshield cowl. TBD if it will do anything other than funnel hot air leaking from under the hood into the car.

Looks like it's gonna be slick.

[jannes_z-28]

I promised to report how this worked out after some summer driving, well now when the winter is around the corner I can report.

The air inside the car feels a lot fresher, the problem seems to be that the Vintage Air unit can't keep up with the warm air coming in and there fore doesn't cool the inside as much as it did before this mod. Since I can control the valve on the inlet I restricted the airflow to maybe 25% and that made the VA unit cool more. And the air still felt fresh.

Strongly recommend doing this.

JAn

[Twentyover]

Interesting writeup. I work for one of the US auto manufacturer's in the interior HVAC engineering group,and we are doing something similiar. The US Environmental Protection Agency (EPA) has made some rule changes recently, with the shift in fuel mileage standards. In the US, the EPA is responsible for determining rules for testing and reporting fuel consumption.

Traditionally, fuel economy testing has been run without the A/C running. Recognizing this is not reflecting the way cars are run in service,they are now accounting for additional engine load and resultant fuel consumption impact of an operating A/C. One feature of the new rule is to grant 'CO2 credits' (both real and non-existant fuel economy improvements) for features that result in a reduction of environmental release of greenhouse gasses. One change is improving joint seal (until recently, a single O-ring was used, later multiple O-rings and most recently 'seal washers'.) Use seal washers,and it will result in another mile per gallon showing on the Monroney sticker (the thinking being that since R134a is 1340 times more powerful a green house gas as carbon dioxide, reducing the fitting leak potential should reduce man-made contribution to global warming). Adoption of 1234yf replacing R134a is another.

The connection to this post is, however,a change in the programming for HVAC controls. Traditionally, most OEM A/C's have defaulted to outside air for heating/cooling. They went to recirc in MAX A/C, or would have a manual lever or button for when you encountered outside smells. Part of the new rules give CO2 credits for default running the A/C system in recirc air mode. While I can't say specifically what my employer is doing, addition of humidity sensors driving a fresh air bleed may prevent window refogging, and regular fresh air purges could keep the air from smelling like unwashed gym socks. This change would result in actual fuel economy savings,as compressor pressure ratios would become more favorable, and variable displacement pumps could short stroke requiring less horsepower to run.

[censo69]

Quite a few OE's run software logic that run different amounts of fresh air bleed to balance both power consumption and interior conditions.

I haven't purchased a HVAC system yet as but I will definitely be wanting to incorporate a Fresh Air mode. Jan thanks a lot for the pics I will be doing something similar with mine.

[l_and_t_reproductions]

This is a great idea... I would think you could even use servo's to control the fresh air blend just as is done on the with the evaporator box under the dash.

[Bowtie racing]

Hello Jan,

Do you have GENIV or older unit? I think my car doesnt have those cowl wents? Only lower kickpanel vents. I am just about mounting my interior back and have put speakers in the place of wents..

When first read the VA instructions i was allso really confused how to get fresh air in .. did asked few times of it and then just forget it..

Hmm do i need to take i apart again..

[INTMD8]

I'm curious too if this is a GENIV unit. Can't really tell from the pics.

On my GENIV the blower motor pulls in air from both sides. The only way I can see having a fresh air option that works correctly is to build a plenum around the entire blower motor and having a recirculation door mounted at the end of that plenum (so the blower could take in air from only the cowl or only the cars interior).

Is it possible the way you have it set up now is allowing outside air to backfeed and enter the cabin rather than 100% of it being forced through the evaporator?

[jannes_z-28]

I have a Gen III unit, the Gen IV unit came out just when I had got mine


Jan

[jannes_z-28]

Update on this topic.

I was out driving the other day and ran into a thunderstorm, it rained heavily and traffic had to slow down to 30 mph on the highway.

Good thing was that my windshield never fogged up as it would have done before I did this mod. Before the windshield would have fogged up instantly with zero visibility.



Jan

[PonchoJohn]

Jan,
If you select HOT and engage the compressor, your windows should be cleared very fast. By selecting HOT, you will get dehumidied air that'll remove the moisture from your interior.

[jannes_z-28]

Why should I want to have HOT air in to my car when fresh air solves the problem without any misting windows at all? And I can keep the temperature I have set.

BTW I don't use Vintage Air's control for my unit. I have a more modern Climate control that let me set a desired temperature I want to have. It adjust the fan speed depending on the situation and regulates cold or warm air to keep the setting I have.

A lot better than the crap VA-control that I got with the unit. It looks like it was made with 1940's technology.


Jan

[andrewb70]

....

BTW I don't use Vintage Air's control for my unit. I have a more modern Climate control that let me set a desired temperature I want to have. It adjust the fan speed depending on the situation and regulates cold or warm air to keep the setting I have.


Jan

Jan,

Do you have a picture and more information on this?

Andrew

[cactuss4]

Jan,

Do you have a picture and more information on this?

Andrew

Second.. Can't throw that out there without some reference

Tory