Investment cost and the running cost of idling, APU unit, and Mark 2 AC

Comparison of Idling, APU unit, and ZERO BREEZE Mark 2.

In the middle of July, the United States is boiling. After a long day at work, truck drivers must rest for 10 hours. The full-time driver probably drives 20 out of 30 days a month; The hottest months are June, July, and August; So there will be at least 60 days. However, we are adding 10 days from May and 10 days from September because these days are also very hot. We have about 80 hot days a year when we need air conditioning for 10 hours of rest and nights of sleep.

In order to keep cool in the hot summer, most drivers idle their trucks to keep the air conditioner running. Some of them install an APU unit or a ZERO BREEZE Mark 2 in their truck. We will compare these three cooling methods based on the 10-hour rest time year-round. We will use a formula to compare each cost of these units. Since gas prices go up crazy, high in California at $6.65, and low in Texas at $4.92. This certainly puts a lot of pressure on truck drivers. We are going to use an average of $5 in the formula.

Comparison of Idling, APU unit, and ZERO BREEZE Mark 2.


First, we need to figure out how much fuel an average semi-truck uses per hour. According to a Google search, it is about 0.8 gallons of fuel per hour. The formula is going to be: gallon * fuel price * hours * days. Based on the numbers we have now, for a one-year idling truck, it is going to be 0.8 gallons * $5 per gallon * 10 hours * 80 days = $3,200. So $3,200 is what it costs to idle a truck per year. It could be more or less, you can make your own formula to see how much it costs. From the same formula, two years will be 0.8 gallons * $5 per gallon * 10 hours * 160 days = $6,400. And five years will be 0.8 gallons * $5 per gallon * 10 hours * 400 days = $16,000.

Idling is not recommended. It can be harmful rather than helpful. There are several reasons. Idling a truck can shave time off of a truck’s engine. Truck engines have a lifespan, idling the truck will shorten the time of each engine. Damaging air quality is another result of idling. It produces tons of carbon dioxide, nitrogen oxides, and particulate matter annually. This leads to climate change and local air quality, which can affect the health of the community and truck drivers. In addition, trucks waste thousands of gallons of diesel per year because of idling. When the truck is idling, it uses a lot of gasoline and costs a lot of money, as we can see from the numbers above.

How much fuel an average semi-truck uses per hour


Some truck drivers are considering installing APU. This allows us to turn off the engine on the truck. Most Auxiliary Power Units (APU) are also powered by diesel. Diesel APU allows truck drivers to use it wherever they need it, and it can power other things, such as a refrigerator or a microwave. According to a Google search, a new APU unit costs $8,500 to $13,000 including installation. Depending on the design and power consumption, a truck APU burns 0.1 to 0.5 gallons of fuel per hour. We are going to use the $8,500 for the APU, 0.3 gallons of fuel per hour and the fuel price remains $5 in our formula. So the formula will be gallons * fuel price * hours * days. In one year of use, it will be 0.3 gallons * $5 * 10 hours * 80 days = $1,200. Two years will be 0.3 gallons * $5 * 10 hours * 160 days = $2,400. And for five years there will be 0.3 gallons * $5 * 10 hours * 400 days = $6,000. Those are how much we can add on for fuel on top of the investment when you own an APU unit. Besides, the unit on its own costs $8,500, the total cost in 5 years will be $6,000 + $8,500 = $14,500. The APU unit is the largest investment. The numbers could be higher or lower depending on the model, fuel prices, power consumption, etc. Truck drivers can calculate the numbers in their own situations.

The good thing about APU is that it has enough power to run everything in the truck. It can not only power the AC, but also power the refrigerator or microwave, or charge a few other things. However, it requires installation and regular maintenance, which will add additional costs per year. It also needs to have a medium-range BTU air conditioner. And the particulate matter emissions of diesel APUs are higher than those of truck engines. Diesel APUs must be equipped with a diesel particulate filter when in use. So APU could be an option, but it's still not as good as we want.


The ZERO BREEZE Mark 2 is sold in three models. BASIC has only the air conditioner, which costs $999. The PLUS is a body with one battery that costs $1,499, and the PLUS EXTRA comes with two batteries that cost $1,949. Two batteries can power Mark 2 for up to 12 hours of use, which is perfectly enough for 10 hours of rest. The official website offers an extension dock for 2-batteries users. The dock allows users to place the air conditioner away from the batteries, and more importantly, it can charge those batteries and run the AC unit simultaneously. It only cost $130, so it is a substantial investment for a small amount of money.

Price of ZERO BREEZE Mark 2

Based on the formula we used in the last two theories, gallon * fuel price * hours * days. Here is the result: 0 gallons * $5 * 10 hours * 80 days = $0 for 1, 2, and 5 years. Although there is an initial cost of $1,949 + $130 = $2,079, there is no additional cost to run Mark 2 because it is a battery-powered unit. Drivers can charge both batteries along the way in 7-11 driving time, and it only takes about 7 hours to recharge both batteries. The ZERO BREEZE Mark 2 is the most affordable overall.

The ZERO BREEZE Mark 2 is a 2300 BTU air conditioning unit. Compared with truck engines and APU, Mark 2 has fewer BTUs. It won't beat the sun, but drivers usually only need it in those 10 hours of rest. Mark 2 can cool about 20-40 square feet of area, which is enough for the truck cab. For a better cooling effect, drivers may need to set up a curtain to separate the front and back to create a smaller space and insulate the sleeping area of the truck. The driver also needs to hook up the drain hose that will build up condensation, because Mark 2 is a real air conditioner just like the household one and it takes out the humidity. Drivers don't need to do this with the APU unit and the truck engine, but Mark 2 may be a better choice in humid places. Mark 2 batteries can charge phones or other small devices, but they will not charge large appliances. The portable power station and solar panels can help.

One thing APU and truck engines cannot do is that Mark 2 is portable. Drivers use it as a spot cooler and point the hose in the right direction. Because of the portability of Mark 2, it is easy to carry it anywhere and anytime. It can be taken home and put in the garage, or it can be put in a tent when camping.

In conclusion

Overall, here is a chart of what we have calculated for idling, APU, and ZERO BREEZE Mark 2. The formula is gallon * fuel price * hours * days, plus the initial investment of the unit.

1 year
2 years
5 years
Mark 2 AC
For the 80 hot days of working with the truck, every truck drivers need a good 10 hours of rest. Idling is less recommended. APU units are better than idling the truck, but it does cost a lot of fuel and has other side effects on pollution and noise level. Mark 2 looks expensive in the first place, but it doesn't cost any after purchase. Drivers can do the math in their own situations to find the best fit. Here is a link to gas prices updated daily in different states.


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