Rear Window Air Conditioner

[markopolo]

Originally Posted by Mike

You'd be better to bring a portable floor model with you, and stay at campgrounds with electrical
hookups, and plug in, as an alternative to roof air. You could run the drain hose into the toilet, or
maybe cut a small hole in the floor, and fit it with a removable plug when not used as a drain. If
my roof air ever failed, I could plug a portable floor model in and run my generator to power it, as
long as the draw didn't exceed the generator's capabilities. In fact, if I could find a small footprint
floor model, with a lower draw than my roof air, I could save power and use it instead. Just have
to figure out the footprint and how to store it when not in use.

I wanted to mention power consumption but forgot. Thanks for the reminder.
If you're on a generator I think a higher capacity air conditioner (higher btu rating) would be better because it would cool quicker so you wouldn't have to run the generator as long.
On grid power my a/c unit spec show 4.5 amps current draw. I just looked up the specs on a 13,500 btu Dometic roof air conditioner and it shows 14.9 amps draw. So three hours run time on a small a/c unit uses about the same amount of power as one hour run time on a larger unit.

[Mike]

Originally Posted by markopolo

Anyone know a way to run the van dash air on 110 volt grid power?

Roof air is still the better choice if you need more cooling.

Next time, I'll keep it simple and just say "no".

[markopolo]

Re: running dash air on 110 volt when plugged in

That would be a nice feature in a Class B van. It is probably not doable

[Mike]

If you could duplicate the compressor portion of the system under the hood, and have it driven by an AC powered DC motor, and also allow the fan/blower motor to use either AC or DC power, it could probably be done. There would have to be an automatic selector switch on both, to allow the original automotive system to run the dash A/C system with the engine running, or the additional compressor and blower circuits which would be run off the AC shore power. The drier and condenser and evaporator and expansion valve could be common, and only the inputs and outputs of the compressor would need bypasses or physical switchable valves, unless you could come up with a dual powered/clutched compressor motor, that could selectively be driven by something other than the engine powered belt (as I suggested, a variable speed DC motor, maybe?). It is normally driven by some sort of mechanical drive or serpentine belt in the engine compartment.

Sample diagram of a simple automotive A/C system.....
http://budget-tires.com/ac.html

[Armchair RVer]

Here's a post on RV.net that mentions some problems and there's a photo that shows how much space some units take up: http://www.rv.net/forum/index.cfm/fusea ... m#26235857 Scroll down a bit to the paragraph about the portable air conditioner.

nice piece of work!

[djkeev]

Hmmm ..... grave digging? !?

Anyway.......

The technology exists to run the Dash A/C when parked but the energy consumption will be high.

Today's electric cars and Hybrids such as my Prius use an electric A/C compressor no matter if the car is running on gasoline or electric.

It works quite well.

Now..... Here's the problem. When the Van is parked there isn't any air movement through the radiator and Condensor.
A fan will be needed to suck air through the condensor to cool the super heated refrigeration gas. This won't be a small fan by any means.

So you will need to run....

the In Dash Evaporator blower motor.....
The electric A/C compressor.......
The condensor cooling fan........

Figure up all of those amps needed and you'll soon see that at least on battery power this isn't feasible.

Running on shore power is indeed feasible.

Dave