Having an auxiliary power unit, or APU, installed on your truck is one of those things that you do not truly appreciate it until you have one. Once it has been installed you will never want go back. No more idling for hours on end wasting fuel and hoping not to be caught or fined due to anti-idling laws. No more hotel rooms just to get a decent night’s sleep. The APU gives you the power you need during these times to make your cab comfortable as well as the ability to run other small appliances or electronics.
Choosing an APU can be difficult though folks as there are so many different brands and manufacturers out there today. With all of those choices how do you know that you are picking the right one for you and your needs? In this article we are going to take an in-depth look at one of these APU models known as the Envidia from Thermo King. This is an all electric model that is rated highly from those within the industry. Let’s take a look ourselves:
Diesel Vs Electric
Before we get into the actual review I first want to illustrate to you the differences between an electric and a diesel APU. As I write this article the diesel APU is by far the most popular but in recent years the electric has been making inroads with various city fleets and other applications. What type of APU you need directly depends on what and how you drive. Are you a long-haul driver who is on the road for many nights out of the week? Then chances are a diesel APU will be the best for you. However, if you are smaller distance driver and could use the APU while waiting at a dock or port then the electric model would be best for you.
The electric APU offers you an almost maintenance free APU experience. The downside of these systems though is that they have a limited power supply and when the batteries are depleted you will need to run your truck for another four to eight hours to charge them back to full capacity. A diesel APU on the other hand will run as long as there is fuel in your truck’s fuel tank. Diesel can also provide overall more power when needed then an electric APU. The big downside with diesel is that there are maintenance requirements that take time and money. Keep these facts in mind when reading the review.
Thermoking Envidia Electric APU
I’ll start this off by stating that Thermoking is seen within the industry as the king of APUs. They are the premium model. If you are driving for a fleet and your truck has a Thermoking APU in it then you know your company takes care of its drivers. However, It should be known that there is some debate on who takes the gold medal for APUs. Some truckers and companies prefer the Carrier Comfort Pro over the Thermoking, but I still believe the majority of truckers that state Thermoking is number one and Carrier is a close second.
Features & Components
As I stated at the beginning of this article the Envidia model from Thermo King is an electric APU. This means that there is no engine that comes with this unit, only batteries. This puts you in compliance with all anti-idling laws across the country including California Air Resources Board (CARB). It also prevents you from having to have a secondary diesel particulate filter on your APU. (Diesel APUs require DPFs in California.) This APU also has an overall very quiet operation volume and you will burn even less fuel then you would with a diesel system.
Now for the bad news, since this is an electric system you will need to have a much larger alternator on you tractor truck. Some of you may already have this due to using a large power inverter but for those of you who do not you will need a minimum two-hundred and seventy amp alternator installed to run this electric APU. The other drawback here is that you do not get nearly as many features that you would versus the standard TriPac diesel. An example of this is that the Envidia does not come with a standard heater but instead only comes with the installation kit and the standard eight-thousand BTU air conditioner. While you can still purchase the heater, it is an additional option.
Another point here is that the air conditioner is only an eight-thousand BTU. The TriPac diesel model comes with a thirteen-thousand BTU air conditioner. So, as you can see the amount of power provided by the APU is significantly smaller then that of a diesel… but if you do not need as much power then you’ll be fine!
Along with the seventy-five hundred BTU heater option there are also a one-thousand watt power inverter, solar panel, additional batteries for longer running time, shore power converter, and an even larger heater at nearly fourteen-thousand BTUs. Obviously this depends on your needs but I would definitely opt for the heater and the power inverter. The extra batteries as well if you plan to be running the APU for hours on end. I do like the shore power option though especially if you pass by a lot of rest stops or RV stops. This will give you free reliable power without having to do much of anything.
The battery box is typically mounted on the side of the truck a bit behind the cab and to the left of the fuel tank. This can change depending on your truck but Thermo King stated that this APU can be installed on most any tractor on the market today. I’m sure there are exceptions, so discuss with your dealer before purchasing. The air conditioner’s condenser is mounted on the outside back of your truck so that it is protected from salt and other debris. The evaporator is installed under the bed inside your sleeper cab. The whole unit installed comes in at five-hundred and seventy-two pounds. four-hundred and eighty of that is the battery box/cables and the other ninety is the air conditioner.
On the inside of the cab in the sleeper is the human machine interface, or HMI. The HMI has three easy to use knobs that allow you to adjust the heating and cooling as needed. You will also see various alarm codes on this panel in case something goes wrong with your APU. This same panel also allows you to customize the APU using the control system. This will allow you to program the APU to have it geared towards fuel savings, battery life, or driver comfort. The controller can also be programmed so that heating and cooling does NOT occur during days when the truck is not in use. Since this is an electric APU there is also a battery life alert/sensor on the HMI display as well.
We have established that this Envidia from Thermoking is the premium APU, but now for the bad news. Because this is seen as the premium model you will also see a premium cost associated with it. I have rated the cost for this product as a seven out of ten only because of how expensive it is. These prices can change at any time but as I write this article the average cost for a new Thermoking Envidia system is between ten to twelve-thousand dollars with installation.
While this is a quite an investment many dealers may offer financing options for your purchase. Thermoking also offers a payback calculator which can be found by clicking here. This calculator allows you to put in all of the data for you and your truck and then at the end will provide you with estimated savings as well as an estimated time on when the savings would pay for the APU itself.
Quality & Savings 8/10:
As I stated before, the Envidia is seen as the best of the best. Besides the reputation let us also take a look as to why this is. The first point I want to make is the overall fuel savings you receive when running the APU versus when idling. When a truck idles it typically burns about one gallon of fuel per hour of idling. As you can imagine this can add up quite fast if you are idling for multiple hours at a time multiple days a week. With the Envidia system the diesel fuel burn rate is shrunk significantly to .17 gallons per hour when compared to idling. That is OVER an eighty percent reduction in fuel cost! This feature alone will help pay for the APU after only about a year of having it installed.
The other big point to look at is the maintenance needs of this APU. While the maintenance needs on an electric system are MUCH smaller and less complicated then that of a diesel APU there still needs to be some visual inspection of the cables and harnesses as well as the life of the batteries. The recommended service window on this unit is around two-thousand hours. This should put you right in line with your annual preventive maintenance and inspect for your truck as well.
The last point worth mentioning here is the overall sound level of the APU. Many of the cheaper APUs on the market today have complaints on how loud they are. The Envidia from Thermoking comes in at only fifty-nine decibels. That is little less then the sound of a normal conversation nearby. Compare this to some of the louder APUs on the market place that sound like a lawn mower running and you can physically hear the quality difference coming from the Envidia APU.
Since this is an electric APU the maintenance required is very minimal. At most a visual inspection of the cables and harnesses to ensure everything is connected how it should be and that there is no fraying or damage. Along with this inspection the only other thing you need to look out for is the life of your batteries. Eventually the batteries will need to be replaced. Thermo King recommend a two-thousand hour service window for this APU. That works out to be about once a year for most drivers.
Having this large service window gives peace of mind and truly makes the APU part of your truck instead of a ride along. Other APUs out there with service windows of only one-hundred or five-hundred hours are a pain in the ass as maintenance is required every month or every other month. If something does go wrong with this Envidia APU it comes with service alarm codes to help diagnose and correct the issue.
Thermoking has nearly two-hundred authorized service centers across the United States with many of them offering twenty-four hour service. This puts most of these locations within an hour or two drive from you. It is recommended that any service be done by these authorized service centers. These technicians have been trained on the Thermoking models and know how to diagnose and repair. They also have access to the right replacement parts. If repairs are done at a non-authorized service shop then you may run into difficulty such as not able to find replacement parts or the mechanic simply doesn’t know how to solve the issue.
Thermo King claims that their Envidia APU is the longest running electric APU on the market today. According to them the APU can run as much as ten hours before needing to be charged. Some drivers have stated that they have had theirs last as long as fifteen hours. When the batteries are drained it can take anywhere from four to eight hours of your truck’s engine running to fully recharge the batteries.
One thing to keep in mind though with that battery life is that if you are driving in extreme climate conditions such as extreme heat/cold then your battery charge life can be impacted. As an example, if you are driving through Phoenix in the summer and decide to stay overnight then your air conditioner will be working overtime just to cool the cab off. Because of it constantly cooling the power used will be much higher then normal. This will result in a shorter battery life.
Warranty policy and terms can change but as I write this article I found that Thermo King offers a one year warranty on the Envidia unit and a two year warranty on major components. There was also talk of an extended warranty option that you could be offered at time of purchase. When I was researching this article I found that the Thermo King TriPac diesel model had reports of breakdowns after a few years. The good news here is that with the electric model there are much less moving parts for break downs like this to occur. If something does break the chances are it is small repair due to this being electric.
When something does break you should attempt to seek out a certified Thermo King dealer. If you are not nearby an authorized service center and it is an emergency then you can take it into a mechanic’s shop but they may not know how to work on the Thermoking APU. That is one thing that can be said about the less expensive APU models. A mechanic can typically figure them out and know how to repair them… but with a Thermoking model if you are unable to find a service center then you may have difficulty finding someone who can repair the unit.
As we all know with electric APUs the amount of power that you can use is limited to the amount of power stored in your batteries. With that in mind this is why we see a significantly smaller air conditioner then we do on the diesel model. This isn’t necessarily a fault of this model from Thermo King but just a limitation when it comes to electric APUs. I am still going to give an overall score of eight out of ten in this category as this model is best in class when it comes to electric APUs. If you find yourself needing more power then you should be looking a diesel APU model.
When it is all said and done folks I give the Thermoking Envidia APU a rating of seventy-eight percent. While this scored lower than I had anticipated a big part of the lower score was due to the cost and the reports of downtime after a couple years of service. Do not get me wrong though this is a high quality APU that provides you with a long service window and fuel savings. I do want to state before I close this article that I do NOT own a Thermoking unit.
Instead, this review was written off of my research by talking to those within the industry, reading product information, other reviews, and comparing that information to competitors data. I also want to point out that some of the finer details in this post may change as new models and revisions are released by Thermoking. I hope this article was helpful and provided you some insight before making your APU purchase.
Thanks for reading,