ACtion Magazine - May 2014 - (Page 30)

Verify That Charge By Steve Schaeber or many years now, MACS has been talking about how important it is for vehicles to have the proper amount of refrigerant in their systems. This is no surprise to most of you who follow ACtion magazine, the MACS blog on WordPress, or MACSWorldwide on YouTube. But even though MACS talks about refrigerant charge, it's always nice to have hard data to help back up those statements. The state of Minnesota has been compiling data related to this subject for the past six years, and when you dig into it, the numbers are very telling. Their data shows some averages that are important for technicians and vehicle owners to be aware of. We all know that mobile air conditioners leak. In fact, with few exceptions (like what?), there's no way that they can't leak. What's great to know is how much and how fast they leak. To that end, Minnesota passed a law back in 2007 that requires manufacturers to report the amount of R-134a that leaks from their vehicles. This requirement covers light and medium duty vehicles up to 10,000 pounds GVWR. Specifically, manufacturers must report make, model, type of vehicle, leakage rate in grams per year, original charge amount, and the percentage lost per year from each sample vehicle. This data is compiled by the Minnesota Pollution Control Agency, and what they've found so far is that cars leak an average of about 15.1 grams per year, which is just over 0.5 ounces. This equates to around 2.4% of the original system charge. So, while this may not seem like a lot, keep in mind that this is happening on every single vehicle, and it's happening year after year. So, not only is the cumulative leakage amount high amongst all vehicles on the street, but even on a per-car basis, it's also very high. Just think about it, after 4 years, the average vehicle has already lost about 10% of its charge. F Let's take a look at the Chevy Malibu, for example, and see what's been reported to the MPCA since this program's inception. What this data shows is that the Malibu comes in below the overall average, with a 1.2%/yr leakage rate. It also shows that the system got tighter in the newer models (2013 and 2014). For now, let's keep this in mind: these new, super-tight, low-leaker vehicles won't be seen in aftermarket service shops for a few years yet. We're still working on 10+ year old cars and trucks, with much higher leakage rates than this. It's too bad that no one was monitoring this data over the past 20 years; it would be interesting to see what could be learned from it. So, once again it can't be said enough: one of the most important maintenance steps a technician can take with a mobile air conditioner is to verify that charge. The compressor is the most important part of the system to protect, and proper lubrication is directly tied to refrigerant charge, and the only way to accurately check that charge is with a J2788 R/R/R machine. Of course, we also want to find and fix any leaks in the system, but to ensure its overall longevity, proper charge is paramount. ❆ Author's Note: Do you know of similar studies that have been conducted, or similar data that has been compiled? If so, MACS would love your input! Thanks! Steve Schaeber Manager of Service Training You can reach Steve at 30 ACTION * May 2014 Reader Reply

Table of Contents for the Digital Edition of ACtion Magazine - May 2014

Selling the right things
Season opener
Freeze Frame
Leonard's Law
Service Port
Virtual View
Last Watch
Member Profile
By the Numbers
Cooling Corner
Industry News
Association News
Letter to the editor
New Products

ACtion Magazine - May 2014