In our previous post on how to save 10% in refrigeration costs, we explained how to keeping correct gas levels and clean coils will save you some bucks.

In our second installment, we will get slightly more technical. There is no secret to increasing the efficiency of a vapour compression based refrigeration. Any Cool person will tell you exactly the same thing: Just raise the suction, man.

There are a few ways to raise the suction. The first and most simple is to raise the room temperature set point. By doing this, you achieve two things. First, you reduce the transmission heat load (basically the heat the comes through the walls) and second, because the set point is achieved sooner, the compressor cycles out sooner.

Of course, there is lots of thermodynamics involved, but suffice to say that the longer the compressor runs, the lower the suction pressure goes and the harder the compressor works, to the point where the poor compressor really has to earn his keep. So with shorter run times, the suction pressures are higher which leads to better efficiency.

This brings us to our second way, namely compressor controls. Knowing that short run times results in higher efficiency, your controls should be set up for shorter, more frequent on-times. Simple as that.

Please let us know how you saved some bucks by raising the suction.