Anyone using an air cooled generator to power their A/C units while travelling down the road? I know the water cooled diesel gensets are the best but was just wondering if the air cooled units have ever been used.
You have three issues when using a generator in motion.
First, you need sufficient intake and cooling airflow, and you need the exhaust where the gases won't be drawn into the coach. Also, you MUST REPEAT MUST have carbon monoxide detectors in appropriate places, including one in every confined area where someone might go, including cargo bays (unless you plan to ventilate them for a few minutes before entering).
Second, you need a generator which can handle the gyroscopic forces in combination with the yaw forces of the coach moving. Most can.
Third, you need a mount which can absorb those forces. Again, most can.
The issues are the same for air- or water-cooled -- the only difference is that you can move your heat exchange to another place with water cooling, instead of being forced to cool the genset bay.
The airflow issue can be tricky. Air blowing past the coach can create a partial vacuum in the genset bay, and in the wrong place can mean the genset doesn't get enough intake air to run. This is easily solved by putting an air scoop into the airflow.
Also, air going past the bay isn't the same thing as air coming INTO the bay, and the same partial vacuum can cause overheating. Again, easily solved with an air scoop -- but in cold weather, you can overCOOL an air-cooled engine.
In aircraft, we solve this with adjustable cowl flaps and Cylinder Head Temp gauges. If the CHTs go up, we open the cowl flap a little, letting more hot air escape, if they are too cool, we close the flaps to trap the heat.
The genset in my coach is an Onan air-cooled unit originally intended for standby power use. Since these are often in closed buildings, there is ducting to draw the cooling air from outside and dump the exhaust outside. This makes it easy to control cooling airflow (a simple flap) if I were to set up a scoop. My genset is in the bay where the aircon condenser was, with one wall which is just expanded metal and a nice, big hole in the floor (you want holes in the floor anywhere that you are using propane, which is heavier than air).