APU heating and cooling the cab
We spend a lot of time out here on the road, not always driving. When we are stopped waiting for that next great run we need to be comfortable...
...warm in the winter and cool in the summer. Either running the truck engine or having an Auxiliary Power Unit (APU) can achieve this. An APU is the best choice because it uses the least amount of fuel, most about third of a gallon per hour.
The APU will run an A/C in the summer and provide heat in the winter, also monitoring the battery condition keeping them charged when needed. Most also provide AC current to run the items in the truck we can't live without, such as computers, microwaves, and TV's. There is a down side: most cost $7 to $10 thousand, and they require maintenance. This is not a deal breaker for the service they provide. There are many brands that offer different options; do some research to get the best fit for you. If you spend much time waiting for that load, this could save you thousands in truck engine maintenance each year. Experts will tell us that every hour an engine idles, it's wearing the same amount as if it ran down the road a thousand miles. If your truck is equipped with a Diesel Particulate Filter, idling can do extensive damage because while idling, the exhaust doesn't get hot enough to keep it clean.
Another option is a generator. This only provides AC current for your accessories. Some type of air conditioner will be needed; roof top or under bunk seem to be most common. One can get a small generator from a hardware store, build a bracket to mount it to the truck and wire it up, for less than three thousand dollars, including hardware and the A/C unit. The problem is, these generators are not designed to withstand the abuse of the road, and will, in most cases, not last long, creating a regular investment of a new generator. Then you need to heat for winter. A small electric space heater will work. If this is your choice get one that has good safety features.
There are RV generators that will handle being on the road; again, pricey. They are, in most cases, ready to mount with wiring diagrams and shore power connections. They may also have auto start features like the APU's. The rooftop A/C unit will be needed and it may or may not have heating capabilities. The best option we found for heating is the Espar heater. It will work in any vehicle and it heats like nothing else. With no engine, it makes little noise, and uses a quart or less of fuel in eight hours.
We all use power, even while driving. An inverter is a good compliment to any APU or generator setup. AC power is provided to operate what needs power while the APU is not running, using the trucks batteries to supply the needed DC power. Inverters come in many wattages and will power everything you have, but they can kill the batteries and the alternator if too large. The microwave is usually the largest wattage consumer. Find the label to get its wattage and get an inverter with a higher capacity. One more thing to consider: if you charge electronics (phones, computers) and power flat screen TV's, the output should be "true sine wave". AC power is regulated at 60 htz, in a flowing wave pattern. Less expensive inverters use a "modified sine wave". This will work fine for most items, but some electronics are sensitive to this, and it could cause damage or shorten battery life of the item being charged.