The best transport refrigeration units will have hot gas defrost. So what is hot gas defrost and why should I care. Good question. These are the little things that make a big difference to the well being of your product that you have stored inside your box.
Think back to your school days I know its a reach for some of us. Remember Mrs. McGillicutty’s class on the day she explained what happens to water when it reaches a certain temperature. If you were able to stay awake long enough to hear her say that at 32 degrees water changes from a liquid to a solid in this case ice.
I know folks are saying that's great Tom, but I only need to keep my product refrigerated at 35-40 degrees Fahrenheit that doesn’t apply to me. It absolutely does and here is why:
In order to maintain a box temperature of 35-40 degrees Fahrenheit plus open and closing doors, your evaporator coil has to be 10-12 degrees colder or about 25 degrees to maintain that 35 degree box temperature. So it is a scientific fact that you will get an ice build up on your coil its just a matter of when. Things like moist hot days and door openings can speed up the process but at some point you will need to defrost the ice accumulation on your coil.
There are a few ways to go about this the least effective is someone telling you to just shut off unit for an hour to hour and a half with uncertainty that its defrosted. Can your product really handle those dramatic temperature swings. I always tell our folks that if someone gives you this option run the other direction because they obviously have no concern for the check you wrote for the product inside.
The next method is a step up but not the best and that's electric defrost. The easiest way to describe this is its like having a toaster oven element on the backside of your coil and usually take 30-45 minutes a cycle. It will only defrost the ice where the heat coil is and doesn’t completely remove the ice so you will have to defrost more frequently and running these heat strips are more expensive to operate. Heat strips or electric defrost are less expensive to purchase but more expensive to operate, that's the important takeaway here.
The best and most effective way to defrost the evaporator coil is with hot gas defrost. The simpliest way to explain this is it’s like a heat pump that takes the heat generated from the working compressor and flashes that heat back through the coil internally and in about 3-5 minutes your back in business. This happens so fast that there are no real temp swings in your product insuring safe storage and delivery throughout the day. The takeaways here are the time 3-5 minutes and it happens internally so all the ice is removed, it’s more cost efficient to run and operate.
For more info check out our website at www.coolertrailers.com or plug in our name in itunes and download our podcast to listen to while on the go.
Cooler Trailers incorporate hot gas in to our refrigerated transportation units because it is a more efficient way to keep your investment safe and after all increasing shelf life is what its all about. Our customers agree that Cooler Trailers provides the best transport refrigeration units for this niche.