staying cool mobile

[Opcom]

Mobile operation in summer sometimes means being parked, and it being 100 degrees.

I have noticed my van (2012 E150) does not cool well unless the engine is turning 1500RPM or better. It is not very dependent on vehicle speed or airflow, as the van was rolled at about 15MPH basically idling and the a/c did not do well, but parked and idled up to 1500-2000RPM it does. yes the airflow is there at that RPM, but what is missing while coasting at idle is the compressor RPM and or overall displacement.

Some vehicles might do better, and surely a van puts a big load on, even with a cargo partition. Used to be a bigger vehicle had a bigger a/c though. My '05 chevy truck did. My '93 van had a much better a/c.

I was researching this complaint and it seems the trend from whomever regulates our comfort for us, has been to shrink HVAC systems in vehicles to improve mileage and reduce emissions. The things done are to minimize refrigerant volume (in case of leaks) as well as compressor displacement reduced to 100cc from some larger value (less engine HP consumed) and and condenser volume/size made smaller. It is as wide and tall, but thin.. (goes along with less refrigerant).

so it is pretty clear that parking and idling to do a little mobile SWL or hammy stuff is not going to be as comfortable an experience as I have paid for it to be, that is, I paid for air conditioning as par of the vehicle cost. My 2010 F-550 also had this a/c issue. It's not a Ford thing, those are just the last 2 vhicles.

The workaround is to idle up to about 1800RPM when sitting in 100 degree heat. Of course that defeats the very purpose of fuel consumption reduction. I don't like burning up the extra fuel when I could be just idling. I checked into crank pullys on these grounds as well as getting more alternator and fan action, it already has the biggest pully that will fit.

I think the thing could be fixed with a larger compressor but the question is how to find a bigger one (200cc) that will fit the bracket and hook up. The pully on the compressor is not something that can be changed.

I used to sit in my '05 truck and SWL in the cool a/c. Not any more. Anyone in the South notice this trend? Anybody know anything about modern vehicle a/c?

[kb3ouk]

What about converting it to an electrical fan? Our new Nissan vans at work have a engine-driven van that covers the left 2 thirds of the radiator, and an electric fan that covers the right third. When its parked and idling, you can hear the electric fan turning off and on, but I don't notice it much once the engine gets up to speed.

[wa2fns]

you might try a curtain of sorts in back of the front seats to down size the interior volume

[KD6VXI]

Check into the police / ambulance / tow truck packages.   I don't recall for certain,  but Ford may refer to it as service vehicle package. 

--Shane
KD6VXI

[WD5JKO]

Perhaps the alternator output sags at idle with the AC running. The OEM electrical systems are often poorly done. Check out this site for ideas:

http://ceautoelectricsupply.com/chargesystemupgradekits.html

Jim
Wd5JKO

[WQ9E]

Having the AC set to recirc mode will generally help unless you are really creating a lot of heat inside the van.  Otherwise as suggested reduce heat gain from sunlight via shades, window tint, etc.  A more extreme change would be to change the compressor pulley diameter but make sure that this change doesn't place the compressor above rated RPM at the governed engine speed.

In slow speed stop and go traffic I set the Allison transmission in my 2006 GMC Sierra diesel to tow/haul mode which delays upshifts keeping the RPM higher which allows great AC operation.  Otherwise it is often running at 1,000 RPM in low speed driving which doesn't spin the compressor fast enough in really hot weather.  This mode also leaves the torque converter locked which reduces the amount of transmission heat and its secondary cooler is in the very front of the cooling stack.

[WU2D]

Mobile operation in summer sometimes means being parked, and it being 100 degrees.

Dallas in the summer? Wow that is an understatement. I once tried to walk from the Gaylord in Grapevine to the Bass Pro (Big Racks) which looked like it was just "up the road" and almost died. And that was at 5 PM.

It hot.

[AJ1G]

Assuming you have electric fans, `they should  most likely be running  with the A/C on.  I have had several Fords that had at least one of two fans run continuously with the A/C on.  My 2001 Pontiac cycles the fans on compressor R-134 pressure, it makes very cold AC even at idle.  Perhaps your fans are not working right?

[Opcom]

No, but those are things I already looked at.

The conditions where it does not work well are:
idling, but moving 15 miles an hour (rolling down hill, good air flow)
idling, not moving.

The conditions where it does work well are:
moving 15 miles an hour in any case.
1500 RPM and moving 15 miles an hour (rolling in 2nd gear).
1500RPM and not moving with fan clutch operating normally so that fan turns about the same speed as idle half the time.

The result of the logic, to me, is that:
there is adequate air flow at idle from the fan.
 (The fan clutch tends to stay engaged at idle. It's a big diameter fan and a big radiator and condenser in a work truck, slow turning large size equipment moves a lot of air.)
There is inadequate refrigerant volume from the compressor at idle to cool adequately on recirculate. It's an idiotic 'economy feature' I want to workaround.

The only condition under which the cooling is inadequate is when the compressor speed is low.
It has less to do with vehicle speed or the need for more air flow at idle.
Adequate compressor pressure output would be indicated by compressor cycling.
One could be sure it is a good test of this if the vehicle is started cold and:
 1. it does not cool good
 2. the compressor never cycles despite the cool equipment condition.
   (meaning the evap sensor never hits near 33 degrees to cycle it nor does the unit cycle from pressure.)
The charge in the system is correct.
There is a partition in the van.

I looked at adding an auxiliary system but the cost is a high. The displacement on the factory compressor is only about 0.98 cubic inch according to research. A 2 cubic inch one would likely be enough, cycling is OK if that is what it takes. On other equipment such as loaders and tractors where the thing has to cool regardless of idle or high RPM, a 2 CI compressor is used with even smaller condensers and evaporators. A large compressor is frequently used on heavy duty cab systems.

[wa2fns]

Have you checked the operating pressures at idle ? R134a is funny acting in comparison to R12 when the system is just a few ounces low.I use a low side of about 40/50 to as much as 275 high side on 90 degree days here in Florida.Have had compressors that are weakening give similar symtoms

[W7TFO]

If you have to do a top-off or recharge, I recommend trying Red-Tek as opposed to a Freon-based refrigerant.

It is a pure propane, and doesn't care what oil is in the system.  It also runs with lower head pressures, and since it is not ozone-depleting, you can buy it without a license.

I bought a large drum of it for $275 delivered, and run it in everything here now.  It is compatible with flourocarbons as well.  Cools much better than R-134, on par with R-12.

73DG

[AJ1G]

Also, wonder if you have gone on a forum that focuses on your specific make and model of vehicle.  Chances are you are not the first to have the problem you  are describing with your A/C, there are likely others with similar vehicles who have a lot of tribal knowledge on your specific problem, especially if its a common "design" problem. I have been helped out numerous times over the years on vehicle forums and lists for our Volvos , Ford Escort, Pontiac Grand Prix,and my son's Mercedes diesel wagon.

[ka4koe]

Have you considered window tinting to reduce interior heating via windows???