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Increasing fresh air flow through vents

8961 Views 32 Replies 13 Participants Last post by  3-Wheeler
:?: Has anybody modified their vent system to boost the amount of fresh air coming in through the vents beyond the somewhat feeble amount with the fan at max? :?:

I find that if I just dial up the fan to max, it is not really max. If I dial up the auto/econ ac/off and THEN after than set the fan to max, it is more max than the other max.

In either case, it is not pumping as much fresh air into the car interior as I experience in my other car when I have that blast just fresh air. That one makes a hurricane, and really cuts down on AC usage.

I am considering trying to figure out a way to make the vents deliver more fresh air than they do now, so that I can run the AC less and keep the windows up.

Has anyone posted any mods like this?

p.s. I can suffer for the mpg under most conditions, but this mod is for my bulldog who can't tolerate anything much higher than about 81 or 82 degrees. Today I drove a long drive with him and it was in the mid 70s outside, but the sun made it over his threshold without the AC or periods of windows down both of which wacked my mpg even with slowing down.
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Just in case, have you replaced your AC air filter in the last year or two. It could be filled with leaves or something.
figgy said:
Has anybody modified their vent system to boost the amount of fresh air coming in through the vents beyond the somewhat feeble amount with the fan at max?

Another problem in addition to increasing the flow is the heating of the air due to the intake location, cowl at the base of the windshield and the proximity of the heater core. Expect 10+F additional heating on warm days.

Its both a problem of intake location and the available "real estate" under the dash. There's simply not enough space to insulate fresh air from the heater core. The heater core needs a small continuous flow to prevent it from clogging. Without this flow mineralization and galvanic corrosion would accelerate the core's aging.
Tinted windows would be helpful.

Don't think its an easy job or even possible. Block off the heater core and drain it.
You could replace the input filter with open cell foam. Since air input is a function of air output you could find a way to increase the air flow out of the car. The rear of the car creates a negative air pressure at speed. Jamb open the existing vent or add a supplemental vent. Hmmmmm, go crazy and add a solar powered air exhaust fan. :wink:
take a look at thermo-tec web site. they sell some items that you could wrap aroun the duct work to deflect heat.
It agree that something at the rear of the car that 'ejects' the hot cabin air will do wonders - and do a lot more than trying to squeeze more cool air into the cabin for the same effort.

A solar fan would be a nice touch for this.

One could put a vent system to eject hot air out through the bottom where the thin flooring is around the tire area. I'll have to take a look.

I am trying to make everything reversible, so I hope there is a way to do it without cutting up the rear metal sheeting.

Sun blocking by window shades or tinting is pretty darn simple!
Hmm, never thought of that, but yes, allowing the air to exit will help a lot. I don't know how much airflow is possible through the passenger side battery vent, but maybe air could be pushed out there and vented out the bottom of the battery compartment somehow?

That would also apply additional cooling for the battery, which might mean the battery cooling fan wouldn't have to work as much. Then again, batteries work better when warmer so it might have a downside too.
I've allready put a small solar panel and a 12v computer fan in the rear storage compartment with a cutout.

I think I need a larger fan because the little fan helps none to very little.

The car just absorbs so much heat! Best bet is to park in the shade.
Air ejection fan through rear compartment

I am revisiting this here topic, as it is getting hot now.

Did you try just shooting air out through the side vents in the rear cargo area?

Do these rear compartment vents really vent to the outside, or are they there just to tempt us?

Was it a high CFM fan, or an anemic little baby fan?

Did you try it with a larger one?

I am working on a solar system for parked air ejection, and a manly-man fan for driving. They may be apples and oranges.
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I am working on the installation of Quad cooling fans to vent air out the cargo area side vents powered by solar energy.

In a test so far, it seemed that it kept the car temp down, so I am doing the permanent installation in Edwin (now GAIACAR).

So far no holes cut anywhere...

I am waiting on some fancy flexible panels to add to the high tech effect...

All is 12V, so I should be able to power from the car 12V if I need extra juice when driving...
Detailed pic's, narrative and a parts list please. :)

I wouldn't ask you for anything I wouldn't, er haven't provided myself. <g>
Solar Powered Quad Fan Install

I finally put up the stuff about the solar fan installation.

Solar powered forced venting quad fan installation:


I included pictures of the first solar vents I tried for the windows so you know to NOT buy them if you see them in a store. They are a good idea in that venting hot air out is good, but the execution was poor.

I used 4 fans to get better airflow and so I can talk about a 'quad fan' system which sounds very sophisticated.

I have to add at least one other fan to stir the air around the ceiling and shoot it back to the outside vents.

I really would love to have someone other than me rip open their rear cargo area down to the metal and find out where the side vents really end up. I am thinking that a fan could be placed deeper inside that area, but I don't want to rip it out unless I can put it back together after I put the fan into it.

These modern solar panels kick arse, as the three 5W panels make more than enough juice to blast the quad fan system. Although "" sounds kind of silly, they have rock bottom prices and shipped the real deal quickly.

8) Most importantly, it really does work!
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I got my best RWC - SLO (220 miles) trip mpg using these to keep me and the dog cool.

It's a personal record of 92.5 mpg for the trip down.

I only had to have the windows cracked and then partially open at the end as the air temps began to climb. Before I had to have them open all the way or run AC to keep temps OK for the pooch.
arent those vents on the sides to vent the gases produced when the batteries are charge when regenerativly braking or from the engine when low charge?
If you probe into them they go into the space in the body panels. It isn't clear how the path to the outside works, but air goes in them and doesn't come out.

I am sure it helps mpg and overall car temperature when it is hot to increase air flow to the batteries as well, which this must be doing at the same time since that whole area is at least partly linked.

These batteries do not produce an gas by products. They aren't like the old lead acid batteries. The battery venting is for temperature management.

Keeping the bats at a modest temp in hot weather rather than having them rise to extremes I gather should make them perform better and last longer.
I really enjoyed reading your write up regarding the solar fans. Thanks for the link to I checked out the site and downloaded a PDF brochure. I think that one more solar panel could be fit into the hatch area if you had the rigid ones and made the right adaptor. If you used the area between the upper and lower window it would not block the view and would not eat into the storage area too much. It's nice that they are so light. :D
figgy said:
These batteries do not produce an gas by products. They aren't like the old lead acid batteries. The battery venting is for temperature management.
oh...sry, i used to be a nut for the EV conversion thing (never did get around to it) and just rememebered that you had to vent the batteries when you recharged cuz it gave off Hydrogen gas.
Source for 12V from car

FYI: For the Insight power 12V I just used a plug into the accessory plug.

Since it seems to be working really well, if I were really energetic I would direct wire it somewhere and install the Sun/Moon switch in the console rather than have it as an external box.

The only problem is that you want to be able to move the solar panels around depending on the sun (maybe on the dash, maybe in back on another day) so you need at least some wires flopping around in order to let you do that.

The bummer is that there is too much reflection to have panels permanently on the dash.

If only they could be on top of the car... but someone might steal them...
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