Air Condition vs Windows Down

[RobertSmalls]

One thing that's often underestimated is the cooling power of running the vent fan on full, with the A/C off.

Interestingly, the part number for the Insight's blower motor is the same as that of the Odyssey minivan. Lots of Insights left the factory with no A/C, and I guess Honda considers an oversized fan a viable alternative for customers who are very dedicated to FE.

[cfg83]

Hello -

I have been considering trying to isolate the front seat volume of the car from the rest by using bubble-pack insulation that is reflective foil on the outside. It would be a sheet at just-below-headrest-height and directly behind the front bucket seats. That should make it so that I only cool the front two seats when I am commuting.

CarloSW2

[Piwoslaw]

Originally Posted by cfg83

For instance, if you have a V8, the A/C is a lower percentage of your engine load, so it's a more reasonable tradeoff. On my 1.9 liter 4-banger, it has a much bigger effect and I can really feel the HP drain when I try to accelerate. I can see A/C killing my MPG on the ScanGauge because the engine load is much greater.

This is something to remember: just because it is a lower precentage of engine load, and/or does not noticibly change acceleration, doesn't mean it uses less fuel. In fact, I wonder if cars with bigger engines also have a larger A/C system?

[jamesqf]

There's something missing here. What is more comfortable? May just be me, but I think that when the outside temperature is at all reasonable - say low 90s or less hereabouts - it's a lot more comfortable to have windows open and outside air blowing through, than to have icy blasts from the A/C blowing at you.

Probably healthier, too.

[lunarhighway]

i don't have AC so i'm committed to the blower. i usually crank the rear windows slightly and when i start run the blower full blast, so as to force all the hot air out of the car.

with the rear windows only a an inch or two open the blower creates a noticable pressure increase in the car, and as hot air rises this should be the first air to go out the window. then i set it to a more moderate level, and at stops or in crawl traffic i open the front windows full.

i think because of the A pillar vortex i think it's aerodynamically better to crank the rear window vs the front, also because air is blown in from the front to it makes sense to evacuate it as far back as possible.

perhaps slightly off topic, but usefull in the bigger picture as a fuel saving measure is to make a habit of shielding the windows from the outside with reflective window covers... these usually have two wings you clamp between the doors so they don't fly off, and should prevent the car from heating up when parked... or choose tinted windows or apply (partial) film

[cfg83]

jamesqf -

Originally Posted by jamesqf

There's something missing here. What is more comfortable? May just be me, but I think that when the outside temperature is at all reasonable - say low 90s or less hereabouts - it's a lot more comfortable to have windows open and outside air blowing through, than to have icy blasts from the A/C blowing at you.

Probably healthier, too.

I am not in disagreement with anyone here, but when I am driving as a commuter, the other passenger is my guest. Also, the freeway air isn't the cleanest air you can breathe. I'll do it on my own, but I won't force it on a co-worker/friend.

CarloSW2

[Daox]

My normal cooling routine:

1) Jump in the car and roll down the windows until out of the parking lot. (Actually, I'll go to my car at work a few hours before hand and roll the windows down & crack the sunroof open)
2) Get on the road, windows up and adjust fan speed until comfortable.
3) If too hot (rarely the case), turn A/C on to the coldest setting and at lowest fan speed and use recirculation.
4) If still too hot, turn fan speed up until comfortable/tolerable.

By adjusting the fan speed you don't have to P&G the A/C. It will P&G itself and the car stays at a more even and comfortable temperature.

[cfg83]

Piwoslaw -

Originally Posted by Piwoslaw

This is something to remember: just because it is a lower precentage of engine load, and/or does not noticibly change acceleration, doesn't mean it uses less fuel. In fact, I wonder if cars with bigger engines also have a larger A/C system?

Yes, that is a very good point. From a logical(?) POV, I would venture to guess that the A/C system is sized according to the interior cabin volume. Sooooo, an A/C for a vanilla two-seat truck *should* be smaller than one for an extended cab.

On the other hand, it's cheaper to make one A/C for both models, so making one A/C sized for the extended cab and installing it into the vanilla two seater also makes "sense" ... from a different POV.

CarloSW2

[jamesqf]

Originally Posted by cfg83

...when I am driving as a commuter, the other passenger is my guest. Also, the freeway air isn't the cleanest air you can breathe. I'll do it on my own, but I won't force it on a co-worker/friend.

I agree, but have you asked the passenger what they prefer? Maybe they're thinking "Gee, I wish he'd just roll down the window instead of running the A/C..."

And another good point about freeway air, since I seldom drive on freeways. I get pine-scented mountain air instead - or the sagebrush-scented desert variety.

[Daox]

Haha, I'm just the opposite. I really don't like having the windows down. You can't hear anything and certainly can't hold a conversation with your passenger(s).